RU2797560C2 - Antibodies to fgfr2 in combination with chemotherapy in cancer treatment - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine and pharmaceuticals. 1 object is a method of treating gastric cancer in a human subject, comprising administering to the subject a therapeutically effective amount of an antibody to fibroblast growth factor receptor 2 IIIb (anti-FGFR2-IIIb) and applying a modified FOLFOX6 chemotherapy regimen (mFOLFOX6), where the antibody to FGFR2-IIIb is afucosylated, where (1) anti-FGFR2-IIIb antibody is administered at a dose of 6–15 mg/kg, (2) at least one intermediate dose of anti-FGFR2-IIIb antibody is administered between two doses (1), (3) mFOLFOX6 chemotherapy includes administration of 50–100 mg/m² of oxaliplatin, 100–400 mg/m² of leucovorin and 100–400 mg/m² of 5-fluorouracil (5-FU) by intravenous infusion or intravenous bolus injection followed by 2,200–2,400 mg/m² of 5-FU for 44–48 hours, and (4) introduction of antibodies to FGFR2-IIIb according to (1) and mFOLFOX6 according to (3) are carried out simultaneously or sequentially once every 13–15 days. Object 2 is a method of treating locally advanced, unresectable or metastatic gastric cancer that overexpresses FGFR2-IIIb in a human subject.

EFFECT: treatment of gastric cancer using the claimed mode of administration of the FGFR2-IIIb antibody in combination with chemotherapy according to the mFOLFOX6 scheme.

43 cl, 3 dwg, 8 tbl, 2 ex

Description

[001] This application claims priority over U.S. Provisional Application No. 62/507,053, filed May 16, 2017, and U.S. Provisional Application No. 62/581,992, filed November 6, 2017, the contents of which are incorporated herein in their entirety. through a link.

FIELD OF TECHNOLOGY

[002] This application relates to the use of antibodies to fibroblast growth factor receptor 2 (FGFR2), including antibodies to the FGFR2-IIIb isoform of FGFR2 (also known as FGFR2b), in the treatment of certain cancers in combination with mFOLFOX6 chemotherapy.

BACKGROUND OF THE INVENTION

[003] Members of the fibroblast growth factor (FGF) family bind to four known tyrosine kinase receptors, fibroblast growth factor receptors 1-4 (FGFR14) and their isoforms, with different FGFs binding different FGFRs to varying degrees (Zhang et al., J. Biol Chem 281:15694, 2006). The protein sequence of human FGFR2 is presented, for example, in the AF487553 locus of the GenBank database. Each FGFR consists of an extracellular domain (ECD) containing three immunoglobulin (Ig)-like domains (D1, D2, and D3), one transmembrane helix, and an intracellular kinase catalytic domain (Mohammadi et al., Cytokine Growth Factor Revs, 16:107, 2005). FGFs bind to receptors primarily through regions in the D2 and D3 domains of the receptors. In the linker between the domains D1 and D2 is a continuous section of acidic amino acids, called "acid box" (AB - "acid box"). The region containing D1 and AB is believed to be involved in receptor autoinhibition, which is attenuated upon ligand binding.

[004] FGFRs are characterized by multiple alternative splicing of their mRNA resulting in multiple isoforms (Ornitz et al., J. Biol. Chem. 271: 15292, 1996; see also Swiss-Prot: P21802 and isoforms P21802-1 through -20 relative to the sequence of FGFR2 and its isoforms). Notably, there are forms containing all three Ig domains (α isoform) or only two Ig domains D2 and D3 without D1 (β isoform). In FGFR1, FGFR2, and FGFR3, all forms contain the first half of D3, designated IIIa, but two alternative exons can be used for the second half of D3, resulting in forms IIIb and IIIc. In FGFR2, they are respectively designated as FGFR2-IIIb and FGFR2-IIIc (or simply FGFR2b and FGFR2c); the corresponding beta forms are designated FGFR2(beta)IIIb and FGFR2(beta)IIIc. The FGFR2-IIIb form of FGFR2 (also referred to as K-sam-II) is a high-affinity receptor for both FGF1 and members of the KGF family (FGF7, FGF10 and FGF22), while FGFR2-IIIc (also referred to as K-sam-I) is well binds both FGF1 and FGF2, but does not bind members of the KGF family (Miki et al., Proc. Natl. Acad. Sci. USA 89:246, 1992). Indeed, FGFR2-IIIb is the only receptor for members of the KGF family (Ornitz et al., 1996, op. cit .) and is therefore also referred to as KGFR.

[005] FGFRs and their isoforms are expressed differently in different tissues. FGFR2-IIIb (and IIIb forms of FGFR1 and FGFR3) is expressed in epithelial tissues, while FGFR2-IIIc is expressed in mesenchymal tissues (Duan et al., J. Biol. Chem. 267:16076, 1992; Ornitz et al. , 1996, op.cit. ). Certain FGF ligands of these receptors have an opposite expression profile. Thus, members of the KGF subfamily, including FGF7 (KGF), FGF10, and FGF22, only bind to FGFR2-IIIb (Zhang et al., op. cit .) and are expressed in mesenchymal tissues and may thus be paracrine effectors of epithelial cells ( Ornitz et al., 1996, op.cit .). In contrast, members of the FGF4 subfamily, FGF4-6, bind to FGFR2-IIIc and are expressed in both epithelial and mesenchymal lineages and may thus perform either autocrine or paracrine functions. The expression profiles of FGFR2 isoforms and their ligands provide for the involvement of FGFR2 in epithelial-mesenchymal interactions (Finch et al., Dev. Dyn. 203:223, 1995), so it is not surprising that FGFR2-IIIb knockout in mice leads to the development of severe embryonic defects and lethality. (De Moerlooze et al., Development 127:483, 2000).

[006] KGF (FGF7) and KGFR (FGFR2-IIIb) are overexpressed in many pancreatic cancers (Ishiwata et al., Am. J. Pathol. 153: 213, 1998), and their co-expression correlates with poor prognosis (Cho et al., Am J Pathol 170:1964, 2007). Somatic mutations in the FGFR2 gene have been found in 12% of a large panel of endometrial (uterine) carcinomas, and were required for tumor cell survival in a few cases studied (Dutt et al., Proc. Natl. Acad. Sci. USA 105:8713, 2008) . In two tumors, the FGFR2 mutation was found to be the same S252W substitution as that associated with Apert's syndrome. Amplification and overexpression of FGFR2 are associated with undifferentiated, diffuse type of gastric cancer, which has a particularly poor prognosis, and inhibition of FGFR2 activity by small molecule compounds effectively inhibited the proliferation of such cancer cells (Kunii et al., Cancer Res. 68:2340, 2008; Nakamura et al., Gastroenterol 131:1530, 2006).

[007] Inhibition of FGFR signaling has been reported to improve antitumor immunity and reduce the likelihood of metastasis in breast cancer. ( See , for example, T. Ye et al., Breast Cancer Res. Treat. 143: 435-446 (2014).) Anti-FGFR2 antibodies have also been investigated, for example, in gastric cancer models. Specific antibodies to FGFR2 are described, for example, in US Pat. No. 8,101,723 B2, including monoclonal antibodies that bind human FGFR2-IIIb but do not bind as well or not at all to FGFR2-IIIc, and vice versa. US Patent Publication No. 2015-0050273 A1 describes certain afucosylated antibodies that bind to FGFR2-IIIb.

SUMMARY OF THE INVENTION

[008] The present invention includes, for example, methods of treating gastrointestinal cancer, such as gastric cancer, in a subject, comprising administering to the subject a therapeutically effective amount of antibodies to fibroblast growth factor receptor 2 (anti-FGFR2) and administering a modified FOLFOX6 chemotherapy regimen ( mFOLFOX6)). In some embodiments, the anti-FGFR2 antibody is an anti-FGFR2-IIIb antibody. In some embodiments, an anti-FGFR2-IIIb antibody has one or more of the following: binds FGFR2-IIIb with higher affinity than FGFR2-IIIc, or does not bind FGFR2-IIIc in a detectable manner; inhibits the binding of FGF2 to human FGFR2; inhibits the binding of FGF7 to human FGFR2; inhibits human tumor growth in a mouse tumor model; induces ADCC activity (antibody-dependent cell-mediated cytotoxicity); has increased activity of ADCC; is afucosylated; and is able to increase the number of one or more PD-L1 positive cells, NK cells, CD3+ T cells, CD4+ T cells, CD8+ T cells and macrophages in tumor tissue in a mouse tumor model compared to a control.

[009] In some embodiments, an anti-FGFR2-IIIb antibody comprises heavy chain and light chain variable regions, wherein the heavy chain variable region comprises: H1 heavy chain hypervariable region (HVR-H1) comprising the amino acid sequence of SEQ ID NO: 6; HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; and HVR-H3 containing the amino acid sequence of SEQ ID NO: 8; and the variable region of the light chain contains: hypervariable region of the light chain L1 (HVR-L1)containing the amino acid sequence of SEQ ID NO: 9; (v) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; and HVR-L3 comprising the amino acid sequence of SEQ ID NO: 11. In some embodiments, the heavy chain variable domain of an anti-FGFR2-IIIb antibody comprises an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO: 4. In some embodiments, the variable domain the light chain domain of an anti-FGFR2-IIIb antibody comprises an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO: 5. In some embodiments, the heavy chain variable domain of an anti-FGFR2-IIIb antibody comprises the amino acid sequence of SEQ ID NO: 4. In some embodiments, embodiments, the light chain variable domain of an anti-FGFR2-IIIb antibody comprises the amino acid sequence of SEQ ID NO: 5. In some embodiments, the heavy chain of an anti-FGFR2-IIIb antibody contains an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO: 2. B in some embodiments, the anti-FGFR2-IIIb antibody comprises an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO: 3. In some embodiments, the heavy chain of the anti-FGFR2-IIIb antibody comprises the amino acid sequence of SEQ ID NO: 2. In some embodiments, the light chain of an anti-FGFR2-IIIb antibody comprises the amino acid sequence of SEQ ID NO: 3. In some embodiments, an anti-FGFR2-IIIb antibody is chimeric, humanized, or human. In some embodiments, the anti-FGFR2-IIIb antibody is selected from Fab, Fv, scFv, Fab', and (Fab') ₂ .

[0010] In some embodiments of the methods provided herein, an anti-FGFR2-IIIb antibody has one or more of the following properties: no fucose at position Asn297; contains the light chain constant region κ; contains the IgG1 heavy chain constant region; has increased ADCC activity in vitro compared to an antibody having the same amino acid sequence that is fucosylated at position Asn297; has increased affinity for Fc-gamma RIIIA compared to an antibody having the same amino acid sequence that is fucosylated at position Asn297; and is able to increase the number of one or more PD-L1 positive cells, NK cells, CD3+ T cells, CD4+ T cells, CD8+ T cells and macrophages in tumor tissue in a mouse tumor model compared to a control.

[0011] In some embodiments of the methods described herein, the subject has gastric cancer that is locally advanced, unresectable, or metastatic. In some embodiments, the gastric cancer is gastroesophageal cancer.

[0012] In some embodiments of the methods described herein, the anti-FGFR2-IIIb antibody is administered at a dose of 6-15 mg/kg, 10-15 mg/kg, 6 mg/kg, 7 mg/kg, 8 mg/kg , 9 mg/kg, 10 mg/kg, 11 mg/kg, 12 mg/kg, 13 mg/kg, 14 mg/kg or 15 mg/kg. In some embodiments, the anti-FGFR2-IIIb antibody is administered once every 10-21 days, once every 10-15 days, once every 10 days, once every 11 days, once every 12 days, once every 13 days, once once every 14 days, once every 15 days, once every 16 days, once every 17 days, once every 18 days, once every 19 days, once every 20 days, or once every 21 days. In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dose of 6 mg/kg, 10 mg/kg, or 15 mg/kg, with the anti-FGFR2-IIIb antibody administered once every 14 days.

[0013] In some embodiments, the anti-FGFR2-IIIb antibody is administered at the following dosage regimen: (a) at a dose of 6-15 mg/kg, with the anti-FGFR2-IIIb antibody administered once every 14 days; (b) at a dose of 6 mg/kg, and the antibody to FGFR2-IIIb is administered once every 14 days; (c) at a dose of 10 mg/kg, and the antibody to FGFR2-IIIb is administered once every 14 days; or (d) at a dose of 15 mg/kg, wherein the anti-FGFR2-IIIb antibody is administered once every 14 days. In some embodiments, (a) the anti-FGFR2-IIIb antibody is administered at a dose of 6-15 mg/kg, 10-15 mg/kg, 6 mg/kg, 7 mg/kg, 8 mg/kg, 9 mg/kg, 10 mg / kg, 11 mg / kg, 12 mg / kg, 13 mg / kg, 14 mg / kg or 15 mg / kg once every 11-17 days, 12-16 days, 13-15 days or 14 days and (b) at least one intermediate dose of 3-8 mg/kg, 5-8 mg/kg, 7-8 mg/kg, 3 mg/kg, 4 mg/kg, 5 mg/kg, 6 mg/ kg, 7 mg/kg or 8 mg/kg is administered between two doses (a) and dose (b) is lower than dose (a). In some embodiments, (i) the dose of (a) is 10-15 mg/kg once every 13-15 days; (ii) the dose of (a) is 15 mg/kg once every 13-15 days; (iii) the dose of (b) is 5-8 mg/kg and is administered 6-8 days after at least one dose of (a) and 6-8 days before the next dose of (a); (iv) dose (a) is 10-15 mg/kg once every 13-15 days and dose (b) is 7-8 mg/kg administered 6-8 days after at least one dose of (a) and 6-8 days before the next dose (a); (v) dose (a) is 15 mg/kg once every 14 days and dose (b) is 7-8 mg/kg administered 7 days after at least one dose of (a) and 7 days before the next doses (a); (vi) dose (a) is 15 mg/kg once every 14 days and dose (b) is 7.5 mg/kg administered 7 days after at least one dose of (a) and 7 days before the next doses from (a); and/or (vii) the dose of (b) is administered after the first dose of (a) in any of (i)-(vi). In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dose of 15 mg/kg once every 14 days, and 6-8 days after the first administration of the anti-FGFR2-IIIb antibody, the anti-FGFR2-IIIb antibody is additionally administered at a dose of 7.5 mg /kg. In some such embodiments, the anti-FGFR2-IIIb antibody is administered at a dose of 15 mg/kg once every 14 days, while 7 days after the first administration of the anti-FGFR2-IIIb antibody, the anti-FGFR2-IIIb antibody is administered at a dose of 7.5 mg /kg. In some such embodiments, the 7.5 mg/kg dose is administered only once, i.e., between the first and second administrations of 15 mg/kg.

[0014] In some embodiments of the methods of the present invention, mFOLFOX6 comprises administering 85 mg/m ² oxaliplatin, 400 mg/m ² leucovorin, and 400 mg/m ² 5-fluorouracil (5-FU) by intravenous (IV) infusion, or intravenous bolus injection. In some embodiments, mFOLFOX6 comprises administering 85 mg/m ² oxaliplatin, 400 mg/m ² leucovorin, and 400 mg/m ² 5-fluorouracil (5-FU) by intravenous (IV) infusion or intravenous bolus injection followed by 2400 mg/m ² 5-FU by intravenous infusion over 44-48 hours. In some embodiments, mFOLFOX6 is administered once every 10-21 days, once every 10-15 days, once every 10 days, once every 11 days, once every 12 days, once every 13 days, once every 14 days , once every 15 days, once every 16 days, once every 17 days, once every 18 days, once every 19 days, once every 20 days, or once every 21 days. In some embodiments, mFOLFOX6 is administered once every 14 days. In some embodiments, mFOLFOX6 comprises administering 85 mg/m ² oxaliplatin, 400 mg/m ² leucovorin, and 400 mg/m ² 5-fluorouracil (5-FU) by intravenous (IV) infusion or intravenous bolus injection followed by 2400 mg/m ² 5-FU by intravenous infusion over 44-48 hours, where mFOLFOX6 is administered once every 14 days.

[0015] In some embodiments of the methods of the present invention, the anti-FGFR2-IIIb antibody and mFOLFOX6 are administered simultaneously or sequentially. In some embodiments, one or more administrations of mFOLFOX6 are performed prior to administration of the anti-FGFR2-IIIb antibody. In some embodiments, two administrations of mFOLFOX6 are performed prior to administration of the anti-FGFR2-IIIb antibody. In some embodiments, the anti-FGFR2-IIIB antibody is administered on the same day as mFOLFOX6 and prior to mFOLFOX6 administration.

[0016] In some embodiments, the gastric cancer was previously determined to overexpress FGFR2-IIIb and/or the gastric cancer was previously determined to have an FGFR2 gene amplification. In some embodiments, the method further comprises determining if the gastric cancer overexpresses FGFR2-IIIb and/or determining if the gastric cancer has FGFR2 gene amplification. In some embodiments, FGFR2-IIIb overexpression is determined at the protein level by an immunohistochemical (IHC) method. In some embodiments, overexpression has been previously determined or is determined by the IHC 3+ signal in at least 10%, 20%, 30%, 40%, or 50% of the tumor cells. In some embodiments, amplification of the FGFR2 gene has been previously determined or is determined by obtaining the ratio of FGFR2 to chromosome 10 centromere (CEN10) using fluorescent in situ hybridization (FISH), where the FGFR2 gene is considered amplified if the FGFR2/CEN10 ratio determined by FISH is greater than or equal to 2. In some embodiments, FGFR2 amplification has been previously detected or is detected in circulating tumor DNA (cDNA).

[0017] Some embodiments of the present invention encompass methods of treating locally advanced, unresectable, or metastatic gastric cancer in a subject, comprising administering to the subject a therapeutically effective amount of an antibody to fibroblast growth factor receptor 2 IIIb (anti-FGFR2-IIIb antibodies) and administering a modified FOLFOX6 chemotherapy regimen ( mFOLFOX6), where the antibody to FGFR2-IIIb contains the variable regions of the heavy chain and light chain, where the variable region of the heavy chain contains:

(i) HVR-H1 containing the amino acid sequence of SEQ ID NO: 6;

(ii) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; And

(iii) HVR-H3 containing the amino acid sequence of SEQ ID NO: 8;

and the variable region of the light chain contains:

(iv) HVR-L1 containing the amino acid sequence of SEQ ID NO: 9;

(v) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; And

(vi) HVR-L3 containing the amino acid sequence of SEQ ID NO: 11;

[0018] where the antibody to FGFR2-IIIb is administered intravenously at a dose of 10-15 mg/kg followed by the introduction of mFOLFOX6, including the introduction of 85 mg/m ² oxaliplatin, 400 mg/m ² leucovorin and 400 mg/m ² 5-fluorouracil (5 -FU) by intravenous infusion or intravenous bolus injection followed by the introduction of 2400 mg/m ² 5-FU by intravenous infusion over 44-48 hours; and where the antibody to FGFR2-IIIb and mFOLFOX6 is administered every 2 weeks. Some embodiments of the present invention encompass methods of treating locally advanced, unresectable, or metastatic gastric cancer in a subject, comprising administering to the subject a therapeutically effective amount of an antibody to fibroblast growth factor receptor 2 IIIb (anti-FGFR2-IIIb antibodies) and administering a modified FOLFOX6 (mFOLFOX6) chemotherapy regimen, where the antibody to FGFR2-IIIb contains the variable regions of the heavy chain and light chain, where the variable region of the heavy chain contains:

(i) HVR-H1 containing the amino acid sequence of SEQ ID NO: 6;

(ii) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; And

(iii) HVR-H3 containing the amino acid sequence of SEQ ID NO: 8;

and the variable region of the light chain contains:

(iv) HVR-L1 containing the amino acid sequence of SEQ ID NO: 9;

(v) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; And

(vi) HVR-L3 containing the amino acid sequence of SEQ ID NO: 11;

where the antibody to FGFR2-IIIb and mFOLFOX6 is administered every 13-15 days and, optionally, where a single dose of antibody to FGFR2-IIIb 3-8 mg/kg is administered 6-8 days after the first dose of 6-15 mg/kg of antibody to FGFR2 -IIIb and before the second dose of 6-15 mg/kg of anti-FGFR2-IIIb antibody. In some such embodiments, (a) the anti-FGFR2-IIIb antibody is administered intravenously at a dose of 15 mg/kg, (b) the anti-FGFR2-IIIb antibody and mFOLFOX6 are administered every 14 days on the same day, and (c) a single dose of 7 5 mg/kg anti-FGFR2-IIIb antibody is administered 7 days after the first 15 mg/kg dose of anti-FGFR2-IIIb antibody and before the second 15 mg/kg dose of anti-FGFR2-IIIb antibody.

[0019] In some embodiments, the gastric cancer was previously determined to overexpress FGFR2-IIIb as indicated by an IHC 3+ signal in at least 10% of the tumor cells, and/or the gastric cancer was previously determined to have gene amplification FGFR2 in ctDNA. In some such embodiments, the subject received two administrations of mFOLFOX6 prior to the first administration of the anti-FGFR2-IIIb antibody.

[0020] The present disclosure also encompasses compositions comprising an anti-FGFR2-IIIb antibody described herein and each of oxaliplatin, leucovorin, and 5-FU, for example, for use in the treatment of gastrointestinal cancers, such as gastric cancer, in patient in any of the above ways. In some embodiments, the compositions comprise a combination of an anti-FGFR2-IIIb antibody described herein and at least one of oxaliplatin, leucovorin, and 5-FU. In some embodiments, the anti-FGFR2-IIIb antibody and at least one of the drugs oxaliplatin, leucovorin, and 5-FU are in separate containers or compartments. In some such embodiments, the compositions contain a combination of the antibody and each of oxaliplatin, leucovorin, and 5-FU in separate containers or compartments. In some embodiments, the compositions further comprise instructions for use in cancer of the gastrointestinal tract, for example in the treatment of gastric cancer.

[0021] In some embodiments of the methods or compositions of the present invention, an anti-FGFR2-IIIb antibody has the heavy and light chain hypervariable region (HVR) amino acid sequences H1, H2, H3, L1, L2, and L3 of the monoclonal antibodies GAL-FR21, GAL-FR22, or GAL-FR23 described in US Pat. No. 8,101,723 B2. In some embodiments, the heavy chain variable region of an anti-FGFR2-IIIb antibody comprises: (i) HVR-H1 comprising the amino acid sequence of SEQ ID NO: 6; (ii) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; and (iii) HVR-H3 containing the amino acid sequence of SEQ ID NO: 8; and the variable region of the light chain contains: (iv) HVR-L1 containing the amino acid sequence of SEQ ID NO: 9; (v) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; and (vi) HVR-L3 containing the amino acid sequence of SEQ ID NO: 11.

[0022] In some embodiments, an anti-FGFR2-IIIb antibody has a heavy chain variable domain that is at least 95%, e.g., at least 97%, at least 98%, or at least 99% identical to the amino acid sequence of SEQ ID NO:4 or contains the amino acid sequence of SEQ ID NO:4. In some embodiments, an anti-FGFR2-IIIb antibody has a light chain variable domain that is at least 95%, e.g., at least 97%, at least 98% identical or at least 99% of the amino acid sequence of SEQ ID NO:5 or contains the amino acid sequence of SEQ ID NO:5. In some embodiments, the heavy chain variable domain is at least 95%, e.g., at least 97%, at least 98% or at least 99% of the amino acid sequence of SEQ ID NO: 4, or contains the amino acid sequence of SEQ ID NO: 4, and the light chain variable domain is at least 95% identical, e.g., at least 97%, at least 98 % or at least 99% of the amino acid sequence of SEQ ID NO: 5 or contains the amino acid sequence of SEQ ID NO: 5. In some embodiments, the FGFR2-IIIb antibody has a heavy chain that is at least 95% identical, at least 97%, at least 98%, or at least 99% of the amino acid sequence of SEQ ID NO: 2; or contains the amino acid sequence of SEQ ID NO: 2. In some embodiments, the FGFR2-IIIb antibody has a light chain that is at least 95%, such as at least 97%, at least 98%, or at least 99% identical. % amino acid sequence of SEQ ID NO: 3 or contains the amino acid sequence of SEQ ID NO: 3. In some embodiments, the heavy chain is at least 95% identical, such as at least 97%, at least 98%, or at least 99 % amino acid sequence of SEQ ID NO:2 or contains the amino acid sequence of SEQ ID NO:2 and the light chain is at least 95%, e.g., at least 97%, at least 98%, or at least 99% identical to the amino acid sequence SEQ ID NO:3 or contains the amino acid sequence of SEQ ID NO:3.

[0023] In some embodiments, the heavy chain variable region of an anti-FGFR2-IIIb antibody comprises: (i) a CDR1 comprising the amino acid sequence of SEQ ID NO: 16; (ii) a CDR2 containing the amino acid sequence of SEQ ID NO: 17; and (iii) a CDR3 containing the amino acid sequence of SEQ ID NO: 18; and the variable region of the light chain contains: (iv) a CDR1 containing the amino acid sequence of SEQ ID NO: 20; (v) a CDR2 containing the amino acid sequence of SEQ ID NO: 21; and (vi) a CDR3 containing the amino acid sequence of SEQ ID NO: 22.

[0024] In some embodiments, an anti-FGFR2-IIIb antibody has a heavy chain variable domain that is at least 95%, e.g., at least 97%, at least 98%, or at least 99% identical to the amino acid sequence of SEQ ID NO: 15 or contains the amino acid sequence of SEQ ID NO: 15. In some embodiments, an anti-FGFR2-IIIb antibody has a light chain variable domain that is at least 95%, e.g., at least 97%, at least 98% identical or at least 99% of the amino acid sequence of SEQ ID NO:19 or contains the amino acid sequence of SEQ ID NO:19. In some embodiments, the heavy chain variable domain is at least 95%, e.g., at least 97%, at least 98% or at least 99% of the amino acid sequence of SEQ ID NO: 15, or contains the amino acid sequence of SEQ ID NO: 15, and the light chain variable domain is at least 95% identical, e.g., at least 97%, at least 98 % or at least 99% of the amino acid sequence of SEQ ID NO:19 or contains the amino acid sequence of SEQ ID NO:19.

[0025] In some embodiments, the anti-FGFR2-IIIb antibody is afucosylated. In some embodiments, the antibody lacks fucose at position Asn297. In some embodiments, the anti-FGFR2-IIIb antibody comprises a kappa light chain constant region. In some embodiments, the antibody comprises an IgG1 heavy chain constant region. In some embodiments, an afucosylated antibody has increased ADCC (antibody dependent cellular cytotoxicity) activity in vitro and/or in vivo compared to an antibody having the same amino acid sequence that is fucosylated in Asn297. In some embodiments, an afucosylated antibody has increased affinity for RIIIA Fc-gamma compared to an antibody having the same amino acid sequence that is fucosylated at position Asn297. In some embodiments, the afucosylated antibody is capable of increasing the number of one or more PD-L1 positive cells, NK cells, CD3+ T cells, CD4+ T cells, CD8+ T cells, and macrophages in tumor tissue in a mouse xenograft and/or in syngeneic tumor model compared to a control (eg, compared to a control antibody that does not target FGFR2).

[0026] It should be understood that both the above general description and the following detailed description are merely illustrative and explanatory, and do not limit the claims. The section headings used in this document are for organizational purposes only and should not be construed as limiting the claimed subject matter. All references in this document, including patent applications and publications, are incorporated herein by reference in their entirety for any purpose.

BRIEF DESCRIPTION OF GRAPHICS

[0027] In FIG. 1 shows the administration schedules for Part I of the dose escalation clinical trial described in Example 1 below. The initial cohort is at dose level 1 and further recruitment of participants will be at dose levels 1, 2, or -1 as shown in the figure according to analysis for the presence of dose-limiting toxicity (DLT) as shown in Table 1 below.

[0028] In FIG. 2 is a flow chart showing the patient examinations to be performed for Part I of the clinical trial described in Example 1 below.

[0029] In FIG. 3 shows the dosing schedules for dose escalation (phase 1) of the clinical trial described in Example 2. The initial cohorts are cohorts 1 and 2, with cohort 3 being opened if needed and another cohort 4 (not shown) also being opened if it is. necessary. Additional details are provided in Example 2 below.

Description of Specific Implementations

Definitions

[0030] Unless otherwise indicated, scientific and technical terms used in connection with the present invention should have meanings that are commonly understood by one of ordinary skill in the art. In addition, unless otherwise required by context, terms in the singular include the plural, and terms in the plural include the singular.

[0031] Examples of techniques used in connection with recombinant DNA, oligonucleotide synthesis, tissue culture and transformation (eg, electroporation, lipofection), enzymatic reactions, and purification techniques are known in the art. Many such techniques and procedures are described, among other places, for example, in Sambrook et al., Molecular Cloning: A Laboratory Manual ( ^2nd ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY (1989)). In addition, typical techniques for chemical synthesis, chemical analysis, pharmaceutical preparation, formulation and delivery, and treatment of patients are also known in the art.

[0032] In this application, the use of "or" means "and/or", unless otherwise indicated. In the context of a claim dependent on another dependent claim, the use of "or" refers to more than one previous independent or dependent claim only as an alternative. In addition, terms such as "element" or "component" include both elements and components that contain a single unit, and elements and components that contain more than one subunit, unless specifically indicated otherwise.

[0033] Used in accordance with the present invention, the following terms, unless otherwise indicated, should be understood as having the following meanings:

[0034] The terms "nucleic acid molecule" and "polynucleotide" can be used interchangeably and refer to a polymer of nucleotides. Such nucleotide polymers may include natural and/or non-natural nucleotides and include, but are not limited to, DNA, RNA, and PNA. "Nucleotide sequence" refers to the linear sequence of nucleotides that make up a nucleic acid molecule or polynucleotide.

[0035] The terms " polypeptide " and " protein " are used interchangeably to refer to a polymer of amino acid residues and are not limited to a minimum length. Such polymers of amino acid residues may contain naturally occurring or non-naturally occurring amino acid residues and include, but are not limited to, peptides, oligopeptides, dimers, trimers, and multimers of amino acid residues. This definition includes both full-length proteins and their fragments. The terms also include post-expression modifications of the polypeptide, such as glycosylation, sialylation, acetylation, phosphorylation, and the like. In addition, for the purposes of the present invention, "polypeptide" refers to a protein that contains modifications such as deletions, additions and substitutions (usually conservative in nature) in the native sequence, provided that the protein retains the desired activity. These modifications may be intentional, such as by site-directed mutagenesis, or may be accidental, such as due to mutations in host organisms that produce proteins, or errors due to PCR amplification.

[0036] "FGFR2" refers to human fibroblast growth factor receptor 2, including any of its alternatively spliced forms, such as splice forms IIIa, IIIb, and IIIc. The term FGFR2 encompasses wild-type FGFR2 and naturally occurring mutants, such as FGFR2-activating mutants such as FGFR2-S252W, which is found in some cancer cells. "FGFR2-IIIb" or "FGFR2b" is used interchangeably to refer to splice form IIIb of the human fibroblast growth factor receptor 2. An example sequence of human FGFR2-IIIb is shown in GenBank accession number NP_075259.4 dated July 7, 2013. A non-limiting example of the amino acid sequence of a mature human FGFR2-IIIb is shown in SEQ ID NO: 1. "FGFR2-IIIc" or "FGFR2c" are used interchangeably for designations for splice form IIIc of the human fibroblast growth factor receptor 2. An exemplary human FGFR2-IIIc sequence is shown in GenBank accession number NP_000132.3 dated July 7, 2013. A non-limiting example of a mature FGFR2-IIIc amino acid sequence is shown in SEQ ID NO: 12.

[0037] " FGFR2 extracellular domain " or " FGFR2 EVA " refers to the extracellular domain of human FGFR2, including natural and engineered variants. An example of FGFR2 EVA is shown in SEQ ID NO: 13.

[0038] The term " antibody " in the context of this document refers to a molecule containing at least the hypervariable regions (HVR) H1, H2 and H3 of the heavy chain and L1, L2 and L3 of the light chain, and this molecule is capable of binding to an antigen. The term antibody includes, but is not limited to, fragments that are capable of binding an antigen, such as Fv, single chain Fv (scFv), Fab, Fab', and (Fab')2. The term antibody also includes, but is not limited to, chimeric antibodies, humanized antibodies, and antibodies from various species such as mouse, human, cynomolgus monkey, etc. It also includes antibodies conjugated to other molecules such as small molecule drugs, bispecific antibodies and multispecific antibodies.

[0039] An "anti-FGFR2" antibody refers to an antibody that specifically binds to FGFR2. An "anti-FGFR2-IIIb" antibody or an "anti-FGFR2b" antibody refers to an antibody that specifically binds to FGFR2-IIIb (also referred to as FGFR2b. Such an antibody has higher affinity for FGFR2-IIIb than for other FGFR2 isoforms such as FGFR2- IIIc In some embodiments, the antibody may not bind to FGFR2-IIIc in a detectable manner The terms anti-FGFR2 antibody, anti-FGFR2-IIIb antibody, and anti-FGFR2b antibody clearly include afucosylated forms of such antibodies.

[0040] The term " heavy chain variable region " refers to the region containing the heavy chain HVR1, framework region (FR) 2, HVR2, FR3, and HVR3. In some embodiments, the heavy chain variable region also contains at least a portion of FR1 and/or at least a portion of FR4.

[0041] The term " heavy chain constant region " refers to a region containing at least three heavy chain constant domains, C _H 1 , C _H 2 and C _H 3. Non-limiting examples of heavy chain constant regions include γ, δ, and α. Non-limiting examples of heavy chain constant regions also include ε and μ. Each heavy chain constant region corresponds to an antibody isotype. For example, an antibody containing constant region γ is an IgG antibody, an antibody containing constant region δ is an IgD antibody, and an antibody containing constant region α is an IgA antibody. In addition, the antibody containing the constant region μ is an IgM antibody, and the antibody containing the constant region ε is an IgE antibody. Certain isotypes can be further subdivided into subclasses. For example, IgG antibodies include, but are not limited to, IgG1 (containing the γ ₁ constant region), IgG2 (containing the γ ₂ constant region), IgG3 (containing the γ ₃ constant region), and IgG4 (containing the γ ₄ constant region); IgA antibodies include, but are not limited to, IgA1 antibodies (containing the α ₁ constant region) and IgA2 antibodies (containing the α ₂ constant region); and IgM antibodies include, but are not limited to, IgM1 and IgM2.

[0042] The term " heavy chain " refers to a polypeptide containing at least a heavy chain variable region with or without a leader sequence. In some embodiments, the implementation of the heavy chain contains at least part of the constant region of the heavy chain. The term "full-length heavy chain" refers to a polypeptide containing a heavy chain variable region and a heavy chain constant region, with or without a leader sequence.

[0043] The term " light chain variable region " refers to a region containing light chain HVR1, framework region (FR) 2, HVR2, FR3, and HVR3. In some embodiments, the light chain variable region also contains FR1 and/or FR4.

[0044] The term " light chain constant region " refers to a region containing a C _L light chain constant domain. Non-limiting examples of light chain constant regions also contain λ and κ.

[0045] The term " light chain " refers to a polypeptide containing at least a light chain variable region with or without a leader sequence. In some embodiments, the implementation of the light chain contains at least part of the constant region of the light chain. The term "full length light chain" refers to a polypeptide containing a light chain variable region and a light chain constant region, with or without a leader sequence.

[0046] The term " hypervariable region " or " HVR " refers to each of the regions of the variable domain of an antibody that are hypervariable in sequence and/or form structurally defined loops ("hypervariable loops"). Typically, native four-chain antibodies contain six HVRs: three in V _H (H1, H2, H3) and three in V _L (L1, L2, L3). HVRs typically contain amino acid residues from hypervariable loops and/or from "complementarity determining regions" (CDRs), the latter having the highest sequence variability and/or being involved in antigen recognition. Examples of hypervariable loops correspond to amino acid residues 26-32 (L1), 50-52 (L2), 91-96 (L3), 26-32 (H1), 53-55 (H2) and 96-101 (H3). (Chothia and Lesk, J. Mol. Biol. 196:901-917 (1987).) Examples of CDRs (CDR-L1, CDR-L2, CDR-L3, CDR-H1, CDR-H2 and CDR-H3) residues 24-34 L1, 50-56 L2, 89-97 L3, 31-35B H1, 50-65 H2 and 95-102 H3. (Kabat et al. , Sequences of Proteins of Immunological Interest, ^5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD (1991)). The terms hypervariable regions (HVRs) and complementarity determining regions (CDRs) refer to portions of the variable region that form antigen-binding regions.

[0047] " Affinity " or " binding affinity " refers to the strength of the total number of non-covalent interactions between one binding site of a molecule ( eg , an antibody) and its binding partner ( eg , an antigen). In some embodiments, "binding affinity" refers to intrinsic binding affinity, which reflects a 1:1 interaction between members of a binding pair ( eg , antibody and antigen). The affinity of a molecule X for its partner Y can usually be represented by a dissociation constant (K _d ).

[0048] "Antibody-dependent cell-mediated cytotoxicity" or "ADCC" refers to a form of cytotoxicity in which secreted Ig bound to Fc receptors (FcRs) present on certain cytotoxic cells ( e.g., NK cells, neutrophils, and macrophages) allows these cytotoxic effector cells to specifically bind to an antigen-bearing target cell and then destroy the target cell with cytotoxins. The primary cells for mediating ADCC, NK cells, only express FcγRIII, while monocytes express FcγRI, FcγRII, and FcγRIII. FcR expression data on hematopoietic cells are summarized in Table 3 on page 464 of Ravetch and Kinet, Annu. Rev. Immunol 9:457-92 (1991). To evaluate ADCC activity of a molecule of interest, an in vitro ADCC assay is performed as described in US Pat. No. 5,500,362 or US Pat. No. 5,821,337 or US Pat. Suitable effector cells for such assays include peripheral blood mononuclear cells and NK cells. Alternatively or in addition, the ADCC activity of the molecule of interest can be assessed in vivo , eg in an animal model, eg as described in Clynes et al . Proc. Natl. Acad. sci. (USA) 95:652-656 (1998). Additional antibodies with altered Fc region amino acid sequences and increased or decreased ADCC activity are described, for example , in US Pat. No. 7,923,538 and US Pat. No. 7,994,290.

[0049] An antibody having "increased ADCC activity" refers to an antibody that more effectively mediates ADCC in vitro or in vivo compared to the parent antibody, wherein the antibody and the parent antibody differ in at least one structural aspect, and the amount of such antibody and the parent antibody used in the assay are essentially the same. In some embodiments, the antibody and parent antibody have the same amino acid sequence, but the antibody is afucosylated while the parent antibody is fucosylated. In some embodiments, ADCC activity will be determined using an in vitro ADCC assay such as disclosed in U.S. Publication No. 2015-0050273-A1, however, other assays or methods for determining ADCC activity may also be used, e.g. , in an animal model, etc. In some embodiments, the antibody with increased ADCC activity also has increased affinity for RIIIA Fc-gamma. In some embodiments, the antibody with increased ADCC activity has increased affinity for Fc-gamma RIIIA (V158). In some embodiments, an antibody with increased ADCC activity has increased affinity for Fc-gamma RIIIA (F158).

[0050] "Increased affinity for Fc-gamma RIIIA" refers to an antibody having greater affinity for Fc-gamma RIIIA (also referred to in some instances as CD16a) than the parent antibody, wherein the antibody and the parent antibody differ in at least one structural aspect. In some embodiments, the antibody and parent antibody have the same amino acid sequence, but the antibody is afucosylated while the parent antibody is fucosylated. Any suitable method for determining affinity for Fc gamma RIIIA may be used. In some embodiments, affinity for Fc gamma RIIIA is determined by the method described in US Publication No. 2015-0050273-A1. In some embodiments, an antibody with increased affinity for Fc gamma RIIIA also has increased ADCC activity. In some embodiments, an antibody with increased affinity for Fc gamma RIIIA has increased affinity for Fc gamma RIIIA (V158). In some embodiments, an antibody with increased affinity for Fc gamma RIIIA has increased affinity for Fc gamma RIIIA (F158).

[0051] A " chimeric antibody " as used herein refers to an antibody containing at least one first species variable region (e.g. mouse, rat, cynomolgus monkey, etc.) and at least one second species constant region (e.g. , humans, Javanese macaque, etc.). In some embodiments, the chimeric antibody comprises at least one murine variable region and at least one human constant region. In some embodiments, the chimeric antibody comprises at least one cynomolgus monkey variable region and at least a human constant region. In some embodiments, the chimeric antibody comprises at least one rat variable region and at least one mouse constant region. In some embodiments, all variable regions of the chimeric antibody are of the first species and all constant regions of the chimeric antibody are of the second species.

[0052] The term " humanized antibody " as used herein refers to an antibody in which at least one amino acid in the framework region of a non-human variable region has been replaced with a corresponding amino acid from the human variable region. In some embodiments, the humanized antibody contains at least one human constant region or fragment thereof. In some embodiments, the humanized antibody is a Fab, scFv, (Fab')2, etc.

[0053] "Human antibody" as used herein refers to antibodies derived from humans, antibodies produced from non-human animals that contain human immunoglobulin genes such as XenoMouse®, and antibodies selected using in vitro methods, e.g. , phage display, and the antibody repertoire is based on human immunoglobulin sequences.

[0054] "Afucosylated" antibody or "devoid of fucose" antibody refers to antibodies of the IgG1 or IgG3 isotypes lacking fucose in constant region glycosylation. Glycosylation of human IgG1 or IgG3 occurs at Asn297 (N297) as a glycosylation of a core fucosylated biantenna complex oligosaccharide ending in up to 2 Gal residues. In some embodiments, the afucosylated antibody lacks fucose at position Asn297. Such structures are designated as G0, G1 (α1,6 or α1,3) or G2 glycan residues depending on the number of terminal Gal residues. See, for example , Raju, TS, BioProcess Int . 1:44-53 (2003). Glycosylation of the CHO-type Fc region of antibodies is described, for example, in Routier, FH, Glycoconjugate J. 14: 201-207 (1997). In an antibody population, antibodies are considered afucosylated if <5% of the antibodies in the population contain fucose at position Asn297.

[0055] "Effector functions" refers to biological activity related to the Fc region of an antibody, which varies depending on the isotype of the antibody. Examples of antibody effector functions include: binding to Clq and complement dependent cytotoxicity (CDC); binding to the Fc receptor; antibody-dependent cell-mediated cytotoxicity (ADCC); phagocytosis; negative negative modulation of cell surface receptors ( eg B-cell receptor); and B cell activation.

[0056] With reference to antibodies to FGFR2, the terms "blocks binding" or "inhibits binding" of a ligand refers to the ability to inhibit the interaction between FGFR2 and an FGFR2 ligand such as human fibroblast growth factor 1 (FGF1) or FGF2. Such inhibition can occur by any mechanism, including direct interference with ligand binding, such as overlapping binding sites on FGFR2 and/or antibody-induced conformational changes in FGFR2 that alter the affinity of the ligand, or, for example, in the case of FGFR2 VAD or fused FGFR2 EVA molecule by competing for binding to FGFR2 ligands.

[0057] The term "isolated" in the context of this document refers to a molecule that has been separated from at least some of the components with which it normally occurs in nature. For example, a polypeptide is said to be "isolated" when it has been separated from at least some of the components of the cell in which it was produced. In the case where the polypeptide is secreted by the cell after expression, the physical separation of the supernatant containing the polypeptide from the cell that produces it is considered to be the "isolation" of the polypeptide. Similarly, a polynucleotide is said to be "isolated" if it is not part of a larger polynucleotide (such as, for example, genomic DNA or mitochondrial DNA, in the case of a DNA polynucleotide) in which it normally occurs in nature, or if it is separated from at least some of the components of the cell in which it was produced, for example in the case of an RNA polynucleotide. Thus, a DNA polynucleotide that is contained in a vector within a host cell may be referred to as "isolated" provided that the polynucleotide does not naturally occur in the vector.

[0058] The term " elevated level " means a higher level of a protein in a particular tissue of a subject compared to the same tissue in a control, for example, in a person or persons who do not suffer from cancer or other conditions described herein. The elevated level can be the result of any mechanism such as increased expression, increased stability, decreased degradation, increased secretion, reduced clearance, etc. squirrel.

[0059] The terms "reduce" or "decrease" or "increase" or "increase" in relation to a protein or cell type means a change in the level of that protein or cell type in a particular tissue of a subject, such as a tumor, by at least 10%. . In some embodiments, an agent, such as an anti-FGFR2 antibody, increases or decreases the level of a protein or cell type in a particular subject tissue, such as a tumor, by at least 15%, at least 20%, at least 25%, at least at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70 %, at least 75%, at least 80%, at least 85% or at least 90% relative to the level before contact with the antibody.

[0060] The terms " subject " and " patient " are used interchangeably herein to refer to a human. In some embodiments, methods of treating other mammals are also provided, including, but not limited to, rodents, monkeys, felines, canines, equines, bovines, porcine, ovine, goat, laboratory mammals, farm mammals, sporting mammals. animals, as well as mammalian pets.

[0061] The term " sample " in the context of this document refers to a composition obtained from a subject that contains a cellular and/or other molecular component that needs to be investigated, quantified and/or identified, for example, based on physical, biochemical, chemical and /or physiological characteristics. An example sample is a tissue sample.

[0062] The term "cancer" refers to a malignant proliferative disorder associated with uncontrolled cell proliferation, unrestricted cell growth, and reduced cell death by apoptosis. The term "cancer of the gastrointestinal tract" or "cancer of the gastrointestinal tract" refers to cancer of the gastrointestinal tract, such as gastric cancer, colorectal cancer, or pancreatic adenocarcinoma. In some embodiments, gastrointestinal cancer is "gastric cancer" or "GC" which, as used herein, includes gastroesophageal cancer.

[0063] In some embodiments, the implementation of the cancer contains amplification of the FGFR2 gene, while in some embodiments, the implementation of the cancer does not contain amplification of FGFR2. In some embodiments where amplification occurs, the FGFR2 amplification includes a ratio of FGFR2:CEN10 (chromosome 10 centromere) > 3. In some embodiments, the FGFR2 amplification includes a ratio of FGFR2:CEN10 ≥ 2. However, in other embodiments, the level of FGFR2 includes a ratio of FGFR2:CEN10 1 to 2, indicating that FGFR2 is not amplified. In some embodiments, mutations or translocations can cause amplification of the FGFR2 gene.

[0064] Amplification of the FGFR2 gene can be determined using, for example, fluorescent in situ hybridization (FISH) assay. Amplification of the FGFR2 gene can also be detected using a blood test or "liquid biopsy". In some blood-based assay embodiments, FGFR2 gene amplification can be detected in circulating tumor cell DNA or "CTC" (circulating tumor cell). Methods for the detection and molecular characterization of CTCs are described, for example, in Alix-Panabieres (2013) Clinical Chemistry 59:1 110-118. In some blood-based assay embodiments, FGFR2 gene amplification is detected in ctDNA. The term "cDNA" refers to "circulating tumor DNA" , which is tumor-derived fragmented DNA circulating in the bloodstream that is not associated with cells. Methods for detecting and molecular characterization of ctDNA are described, for example, in Han et al. (2017) Genomics, Proteomics & Bioinformatics 15:2 59-72 and includes PCR based methods and next generation sequencing (NGS).

[0065] In some embodiments, the cancer overexpresses FGFR2-IIIb. In some embodiments, the cancer overexpresses FGFR2-IIIb to a greater extent than FGFR2-IIIc. In some embodiments, the cancer expresses FGFR2-IIIb at a normalized level that is greater than 2, 3, 5, or 10 times the normalized level of FGFR2-IIIc expression. In some embodiments, the cancer overexpresses FGFR2-IIIb but does not contain an FGFR2 gene amplification, while in other embodiments, the cancer contains an FGFR2 gene amplification and also overexpresses FGFR2-IIIb. Expression of FGFR2-IIIb can be determined at the protein level by immunohistochemistry (IHC), for example, tumor samples taken from a patient, compared with healthy tissue. The terms "FGFR2-IIIb protein overexpression" and "FGFR2-IIIb overexpression" and the like mean elevated levels of FGFR2-IIIb protein, regardless of the cause of such elevated levels (i.e., whether the increased levels result from increased translation and/or reduced protein degradation, another mechanism). or combinations of mechanisms). In some embodiments, FGFR2-IIIb overexpression can be detected at the mRNA level using, for example, techniques such as reverse transcription polymerase chain reaction (RT-PCR) analysis compared to non-cancerous tissue.

[0066] The level of expression of FGFR2 or FGFR2-IIIb using IHC can be determined by assigning a tumor sample IHC score on a scale of 0-3. In the context of this document, a score of "0" is assigned if no reactivity is observed or membrane reactivity is observed only in <10% of tumor cells; a score of "1+" is assigned if there is weak or barely noticeable membrane reactivity in at least 10% of the tumor cells, or if the cells are reactive only in part of their membranes; a score of "2+" is assigned if there is weak or moderate total, basolateral or lateral membrane reactivity in at least 10% of tumor cells; and a score of "3+" is assigned if there is strong total basolateral or lateral membrane reactivity in at least 10% of the tumor cells. In some embodiments, IHC staining of tumor cells with 1+, 2+, or 3+ indicates overexpression of FGFR2-IIIb. In some embodiments, IHC staining of tumor cells with 2+ or 3+ indicates FGFR2-IIIb overexpression. In some embodiments, IHC staining of 3+ tumor cells indicates overexpression of FGFR2-IIIb.

[0067] A "modified FOLFOX6" or "mFOLFOX6" chemotherapy regimen refers to a regimen in which each combination of oxaliplatin (eg, Eloxatin®), leucovorin (eg, calcium leucovorin or folinic acid), and 5-fluorouracil (5-FU) is administered to a patient by intravenous infusion or intravenous bolus injection over about 2-8 hours, followed by an additional infusion of 5-FU by intravenous infusion over about a 2-day period, as provided in the various embodiments described herein.

[0068] " Treatment " as used herein means a therapeutic treatment, for example, in which the goal is to reduce the severity or slow the progression of the target condition or disorder, and also, for example, in which the goal is to inhibit the recurrence of the condition or disorder. In certain embodiments, the term " treatment " encompasses any administration or use of a therapeutic agent to a disease in a patient and includes inhibiting or slowing the disease or the progression of the disease; partial or complete relief of the disease, for example, by initiating regression, restoration or correction of lost, missing or impaired function; stimulating an inefficient process; or bringing the disease to a plateau in order to achieve a reduction in severity. The term " treatment " also includes reducing the severity of any phenotypic characteristic and/or reducing the prevalence, extent or likelihood of that characteristic. Those in need of treatment include those who already have the disorder, as well as those who are at risk for the recurrence of the disorder, or who need to prevent or slow the reappearance of the disorder.

[0069] The term " effective amount " or " therapeutically effective amount " refers to an amount of a drug effective to treat a disease or disorder in a subject. In certain embodiments, an effective amount refers to an amount effective at the dosages and for periods of time necessary to achieve the desired therapeutic or prophylactic result. The therapeutically effective amount of an anti-FGFR2 antibody or chemotherapy regimen of the present invention may vary depending on factors such as the course of the disease, the age, sex, and weight of the individual, and the ability of the antibody or antibodies to elicit the desired response in the individual. A therapeutically effective amount includes an amount in which any toxic or deleterious effects of the antibody or antibodies are outweighed by the therapeutically beneficial effects. In some embodiments, the term "effective amount" means an amount of an antibody that is effective in treating cancer.

[0070] Administration " in combination with " one or more additional therapeutic agents, such as a chemotherapy regimen, includes simultaneous (joint) and alternate (sequential) administration in any order.

[0071] A " pharmaceutically acceptable carrier " means a non-toxic solid, semi-solid, or liquid excipient, diluent, encapsulating material, adjuvant, or carrier conventional in the art for use with a therapeutic agent, which together constitutes a " pharmaceutical composition " for administration to a subject. The pharmaceutically acceptable carrier is non-toxic to recipients at the dosages and concentrations employed and is compatible with the other ingredients of the formulation. The pharmaceutically acceptable carrier is appropriate for the formulation being used. For example, if the therapeutic agent is to be administered orally, the carrier may be a gelatin capsule. If the therapeutic agent is to be administered subcutaneously, the carrier ideally does not irritate the skin and does not cause a reaction at the injection site.

[0072] Additional definitions may be given in the following sections.

Exemplary anti-FGFR2 antibodies

[0073] Exemplary anti-FGFR2 antibodies include antibodies that specifically bind FGFR2-IIIb, ie, anti-FGFR2-IIIb antibodies. In some embodiments, anti-FGFR2-IIIb antibodies bind FGFR2-IIIc with a lower affinity than they bind to FGFR2-IIIb. In some embodiments, anti-FGFR2-IIIb antibodies do not bind to FGFR2-IIIc in a detectable manner.

[0074] An exemplary anti-FGFR2-IIIb antibody for use in embodiments of the present invention is the anti-HugAL-FR21 antibody described in US Pat. through a link. Figures 13 and 14 of US Pat. No. 8,101,723 B2 show the amino acid sequences of the variable regions and full length chains of mature HuGAL-FR21 antibodies and are incorporated herein by reference. The heavy chain variable region sequences of the HuGAL-FR21 antibody are underlined in Figure 13 of US Pat. No. 8,101,723 B2 and are expressly incorporated herein by reference. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297. Additional antibodies that may be used in the embodiments herein include those described in US Patent Publication No. 2015-0050273-A1, which describes certain afucosylated anti-FGFR2-IIIb antibodies, and which is incorporated herein by reference.

[0075] In some embodiments, an anti-FGFR2-IIIb antibody comprises at least one, two, three, four, five, or six hypervariable regions (HVRs; e.g., CDRs) selected from (a) HVR-H1 containing the amino acid sequence SEQ ID NO: 6; (b) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; (c) HVR-H3 containing the amino acid sequence of SEQ ID NO: 8; (d) HVR-L1 containing the amino acid sequence of SEQ ID NO: 9; (e) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; and (f) HVR-L3 comprising the amino acid sequence of SEQ ID NO: 11. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0076] In some embodiments, an anti-FGFR2-IIIb antibody comprises a heavy chain variable region and a light chain variable region. In some embodiments, an anti-FGFR2-IIIb antibody comprises at least one heavy chain comprising a heavy chain variable region and at least a portion of a heavy chain constant region, and at least one light chain comprising a light chain variable region and at least a portion of light chain constant region. In some embodiments, an anti-FGFR2-IIIb antibody comprises two heavy chains, each heavy chain comprising a heavy chain variable region and at least a portion of a heavy chain constant region, and two light chains, each light chain comprising a light chain variable region and at least least part of the light chain constant region. In some embodiments, an anti-FGFR2-IIIb antibody comprises a heavy chain variable region comprising the amino acid sequence of SEQ ID NO: 4 and a light chain variable region comprising the amino acid sequence of SEQ ID NO: 5. In some embodiments, an anti-FGFR2-IIIb antibody comprises a heavy a chain containing the amino acid sequence of SEQ ID NO: 2; and a light chain containing the amino acid sequence of SEQ ID NO: 3. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0077] In some embodiments, the FGFR2-IIIb antibody comprises six HVRs comprising (a) an HVR-H1 comprising the amino acid sequence of SEQ ID NO: 6; (b) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; (c) HVR-H3 containing the amino acid sequence of SEQ ID NO: 8; (d) HVR-L1 containing the amino acid sequence of SEQ ID NO: 9; (e) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; and (f) an HVR-L3 comprising the amino acid sequence of SEQ ID NO: 11. In some embodiments, an anti-FGFR2-IIIb antibody contains six HVRs as described above and binds to FGFR2-IIIb. In some embodiments, the anti-FGFR-IIIb antibody does not bind to FGFR2-IIIc. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0078] In some embodiments, an anti-FGFR2-IIIb antibody competes with an FGFR2-IIIb antibody comprising six HVRs comprising (a) an HVR-H1 comprising the amino acid sequence of SEQ ID NO: 6; (b) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; (c) HVR-H3 containing the amino acid sequence of SEQ ID NO: 8; (d) HVR-L1 containing the amino acid sequence of SEQ ID NO: 9; (e) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; and (f) HVR-L3 comprising the amino acid sequence of SEQ ID NO: 11. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0079] In some embodiments, an anti-FGFR2-IIIb antibody comprises at least one, at least two, or all three HVR VH sequences selected from (a) an HVR-H1 comprising the amino acid sequence of SEQ ID NO: 6; (b) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; and (c) HVR-H3 comprising the amino acid sequence of SEQ ID NO: 8. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0080] In some embodiments, an anti-FGFR2-IIIb antibody comprises at least one, at least two, or all three HVR VL sequences selected from (a) an HVR-L1 comprising the amino acid sequence of SEQ ID NO: 9; (b) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; and (c) HVR-L3 comprising the amino acid sequence of SEQ ID NO: 11. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose in Asn297.

[0081] In some embodiments, an anti-FGFR2-IIIb antibody comprises (a) a VH domain comprising at least one, at least two, or all three HVR VH sequences selected from (i) an HVR-H1 comprising the amino acid sequence of SEQ ID NO: 6, (ii) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7, and (iii) HVR-H3 containing the amino acid sequence selected from SEQ ID NO: 8; and (b) a VL domain comprising at least one, at least two, or all three HVR VL sequences selected from (i) an HVR-L1 comprising the amino acid sequence of SEQ ID NO: 9, (ii) an HVR-L2 comprising the amino acid sequence of SEQ ID NO: 10, and (c) an HVR-L3 comprising the amino acid sequence of SEQ ID NO: 11. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0082] In some embodiments, the anti-FGFR2-IIIb antibody comprises a heavy chain variable domain (VH) sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity with the amino acid sequence of SEQ ID NO: 4. In some embodiments, a VH sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96 %, 97%, 98%, or 99% identity, contains substitutions (eg, conservative substitutions), insertions, or deletions relative to the reference sequence, but an anti-FGFR2-IIIb antibody containing this sequence retains the ability to bind to FGFR2-IIIb. In some embodiments, such an anti-FGFR2-IIIb antibody retains the ability to selectively bind to FGFR2-IIIb without detectable binding to FGFR2-IIIc. In some embodiments, a total of 1 to 10 amino acids have been substituted, inserted, and/or deleted in SEQ ID NO: 4. In some embodiments, the substitutions, insertions, or deletions occur in regions outside of the HVR (i.e., in the FR). Optionally, the FGFR2-IIIb antibody contains the VH sequence of SEQ ID NO: 5, including post-translational modifications of this sequence. In a specific embodiment, the VH contains one, two or three HVRs selected from: (a) HVR-H1 containing the amino acid sequence of SEQ ID NO: 6; (b) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; and (c) HVR-H3 comprising the amino acid sequence of SEQ ID NO: 8. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0083] In some embodiments, the anti-FGFR2-IIIb antibody comprises a light chain variable domain (VL) having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% sequence identity with the amino acid sequence of SEQ ID NO: 5. In some embodiments, a VL sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96% , 97%, 98%, or 99% identity, contains substitutions (eg, conservative substitutions), insertions, or deletions relative to a reference sequence, but an anti-FGFR2-IIIb antibody containing this sequence retains the ability to bind to FGFR2-IIIb. In some embodiments, the anti-FGFR2-IIIb antibody retains the ability to selectively bind to FGFR2-IIIb without binding to FGFR2-IIIc. In some embodiments, a total of 1 to 10 amino acids have been substituted, inserted, and/or deleted in SEQ ID NO: 5. In some embodiments, substitutions, insertions, or deletions occur in regions outside of the HVR (i.e., in the FR). Optionally, the FGFR2-IIIb antibody contains the VL sequence of SEQ ID NO: 4, including post-translational modifications of this sequence. In a specific embodiment, the VL contains one, two or three HVRs selected from (a) HVR-L1 containing the amino acid sequence of SEQ ID NO: 9; (b) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; and (c) HVR-L3 comprising the amino acid sequence of SEQ ID NO: 11. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0084] In some embodiments, the anti-FGFR2-IIIb antibody comprises a heavy chain variable domain (VH) sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97% , 98%, 99%, or 100% sequence identity with the amino acid sequence of SEQ ID NO: 4, and a light chain variable domain (VL) having at least 90%, 91%, 92%, 93%, 94%, 95% , 96%, 97%, 98%, 99%, or 100% sequence identity with the amino acid sequence of SEQ ID NO: 5. In some embodiments, a VH sequence having at least 90%, 91%, 92%, 93%, 94 %, 95%, 96%, 97%, 98%, or 99% identity, contains substitutions (e.g., conservative substitutions), insertions, or deletions relative to a reference sequence, and a VL sequence having at least 90%, 91%, 92% , 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity, contains substitutions (e.g., conservative substitutions), insertions, or deletions relative to the reference sequence, but an anti-FGFR2-IIIb antibody containing this sequence, retains the ability to bind to FGFR2-IIIb. In some embodiments, such an anti-FGFR2-IIIb antibody retains the ability to selectively bind to FGFR2-IIIb without binding to FGFR2-IIIc. In some embodiments, a total of 1 to 10 amino acids have been substituted, inserted, and/or deleted in SEQ ID NO: 4. In some embodiments, a total of 1 to 10 amino acids have been substituted, inserted, and/or deleted in SEQ ID NO: 5. In some embodiments, substitutions, insertions, or deletions occur in regions outside of the HVR (ie, in the FR). Optionally, the FGFR2-IIIb antibody comprises the VH sequence of SEQ ID NO: 4 and the VL sequence of SEQ ID NO: 5, including post-translational modifications of one or both of the sequences. In a specific embodiment, the VH contains one, two or three HVRs selected from: (a) HVR-H1 containing the amino acid sequence of SEQ ID NO: 6; (b) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; and (c) HVR-H3 containing the amino acid sequence of SEQ ID NO: 8; and VL contains one, two or three HVRs selected from (a) HVR-L1 containing the amino acid sequence of SEQ ID NO: 9; (b) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; and (c) HVR-L3 comprising the amino acid sequence of SEQ ID NO: 11. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0085] In some embodiments, the anti-FGFR2-IIIb antibody has a VH as in any of the embodiments above and a VL as in any of the embodiments above. In one embodiment, the antibody contains the VH and VL sequences from SEQ ID NO: 4 and SEQ ID NO: 5, including post-translational modifications of these sequences. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0086] In some embodiments, the anti-FGFR2-IIIb antibody comprises a heavy chain sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity with the amino acid sequence of SEQ ID NO: 2. In some embodiments, a heavy chain sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97% , 98% or 99% identity, contains substitutions (eg, conservative substitutions), insertions, or deletions relative to the reference sequence, but an FGFR2-IIIb antibody containing this sequence retains the ability to bind to FGFR2-IIIb. In some embodiments, such an anti-FGFR2-IIIb antibody retains the ability to selectively bind to FGFR2-IIIb without detectable binding to FGFR2-IIIc. In some embodiments, a total of 1 to 10 amino acids have been substituted, inserted, and/or deleted in SEQ ID NO: 2. In some embodiments, the substitutions, insertions, or deletions occur in regions outside of the HVR (i.e., in the FR). Optionally, the heavy chain of an anti-FGFR2-IIIb antibody contains the VH sequence of SEQ ID NO: 2, including post-translational modifications of this sequence. In a specific embodiment, the heavy chain contains one, two or three HVRs selected from: (a) HVR-H1 containing the amino acid sequence of SEQ ID NO: 6; (b) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; and (c) HVR-H3 comprising the amino acid sequence of SEQ ID NO: 8. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0087] In some embodiments, the anti-FGFR2-IIIb antibody comprises a light chain having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99% or 100% sequence identity with the amino acid sequence of SEQ ID NO: 3. In some embodiments, a light chain sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identity, contains substitutions (eg, conservative substitutions), insertions, or deletions relative to the reference sequence, but an anti-FGFR2-IIIb antibody containing this sequence retains the ability to bind to FGFR2-IIIb. In some embodiments, such an anti-FGFR2-IIIb antibody retains the ability to selectively bind to FGFR2-IIIb without detectable binding to FGFR2-IIIc. In some embodiments, a total of 1 to 10 amino acids have been substituted, inserted, and/or deleted in SEQ ID NO: 3. In some embodiments, the substitutions, insertions, or deletions occur in regions outside of the HVR (i.e., in the FR). Optionally, the FGFR2-IIIb antibody contains the VL sequence of SEQ ID NO: 3, including post-translational modifications of this sequence. In a specific embodiment, the light chain contains one, two or three HVRs selected from (a) HVR-L1 containing the amino acid sequence of SEQ ID NO: 9; (b) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; and (c) HVR-L3 comprising the amino acid sequence of SEQ ID NO: 11. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0088] In some embodiments, the anti-FGFR2-IIIb antibody comprises a heavy chain sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99 % or 100% sequence identity with the amino acid sequence of SEQ ID NO: 2, and a light chain sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% , 99%, or 100% sequence identity with the amino acid sequence of SEQ ID NO: 3. In some embodiments, a heavy chain sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96% , 97%, 98%, or 99% identity, contains substitutions (eg, conservative substitutions), insertions, or deletions relative to a reference sequence, but an anti-FGFR2-IIIb antibody containing this sequence retains the ability to bind to FGFR2-IIIb. In some embodiments, such an anti-FGFR2-IIIb antibody retains the ability to selectively bind to FGFR2-IIIb without detectable binding to FGFR2-IIIc. In some embodiments, a light chain sequence having at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identity contains substitutions (e.g., conservative substitutions), insertions, or deletions relative to the reference sequence, but an anti-FGFR2-IIIb antibody containing this sequence retains the ability to bind to FGFR2-IIIb. In some embodiments, such an anti-FGFR2-IIIb antibody retains the ability to selectively bind to FGFR2-IIIb without detectable binding to FGFR2-IIIc. In some embodiments, a total of 1 to 10 amino acids have been substituted, inserted, and/or deleted in SEQ ID NO: 2. In some embodiments, a total of 1 to 10 amino acids have been substituted, inserted, and/or deleted in SEQ ID NO: 3. In some embodiments, substitutions, insertions, or deletions occur in regions outside of the HVR (ie, in the FR). Optionally, the heavy chain of the anti-FGFR2-IIIb antibody contains the VH sequence of SEQ ID NO: 2, including post-translational modifications of this sequence, and the light chain of the anti-FGFR2-IIIb antibody contains the VL sequence of SEQ ID NO: 3, including post-translational modifications of this sequence. In a specific embodiment, the heavy chain contains one, two or three HVRs selected from: (a) HVR-H1 containing the amino acid sequence of SEQ ID NO: 6; (b) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; and (c) HVR-H3 containing the amino acid sequence of SEQ ID NO: 8; and the light chain contains one, two or three HVRs selected from (a) HVR-L1 containing the amino acid sequence of SEQ ID NO: 9; (b) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; and (c) HVR-L3 comprising the amino acid sequence of SEQ ID NO: 11. In some embodiments, the antibody is afucosylated. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0089] Additional exemplary anti-FGFR2 antibodies are the GAL-FR22 and GAL-FR23 antibodies described in US Pat. No. 8,101,723 B2, incorporated herein by reference. The light and heavy chain variable regions of GAL-FR22, for example, are shown as SEQ ID NOs: 7 and 8 in patent no. patent, which are included in the present description by reference. Hybridomas producing GAL-FR21, GAL-FR22, and GAL-FR23 were deposited with the American Type Culture Collection, PO Box 1549, Manassas VA, USA, 20108, under ATCC numbers 9586, 9587, and 9408, Nov. 6, Nov. 6, and 12 August 2008, respectively. Thus, in some embodiments, an anti-FGFR2 antibody is an antibody comprising the amino acid sequence of an antibody derived from one of these three hybridoma strains.

[0090] The GAL-FR22 heavy and light chain variable regions are also represented herein as SEQ ID NOS: 39 and 43, while the Kabat CDRs are presented herein as SEQ ID NOS: 40-42 and 44- 46. Thus, in some embodiments, the heavy chain variable region of an anti-FGFR2-IIIb antibody comprises: (i) a CDR1 comprising the amino acid sequence of SEQ ID NO: 40; (ii) a CDR2 containing the amino acid sequence of SEQ ID NO: 41; and (iii) a CDR3 containing the amino acid sequence of SEQ ID NO: 42; the variable region of the light chain contains: (iv) a CDR1 containing the amino acid sequence of SEQ ID NO: 44; (v) a CDR2 containing the amino acid sequence of SEQ ID NO: 45; and (vi) a CDR3 containing the amino acid sequence of SEQ ID NO: 46.

[0091] In some embodiments, the anti-FGFR2 antibody comprises an anti-FGFR2-IIIb antibody in which the heavy chain variable domain is at least 95%, e.g., at least 97%, at least 98%, or at least 99% identical. amino acid sequence of SEQ ID NO:39, or contains the amino acid sequence of SEQ ID NO:39. In some embodiments, an anti-FGFR2 antibody comprises an anti-FGFR2-IIIb antibody in which the light chain variable domain is at least 95% identical, e.g., at least 97%, at least 98%, or at least 99% of the amino acid sequence of SEQ ID NO: 43; or contains the amino acid sequence of SEQ ID NO: 43. In some embodiments, the heavy chain variable domain is at least 95%, such as at least 97%, at least 98%, or at least 99% identical to the amino acid sequence of SEQ ID NO :39 or contains the amino acid sequence of SEQ ID NO: 39 and the light chain variable domain is at least 95%, e.g. at least 97%, at least 98%, or at least 99% identical to the amino acid sequence of SEQ ID NO: 43 or contains the amino acid sequence of SEQ ID NO: 43. In some embodiments, the antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0092] In any of the methods described herein, the FGFR2 antibody can be a humanized antibody, a chimeric antibody, or a human antibody. In any of the compositions or methods described herein, the FGFR2 antibody may be selected from Fab, Fv, scFv, Fab' and (Fab')2. In any of the compositions or methods described herein, the FGFR2 antibody may be selected from IgA, IgG and IgD. In any of the compositions or methods described herein, the FGFR2 antibody may be an IgG. In any of the methods described herein, the antibody may be IgG1 or IgG3.

Typical properties of antibodies

[0093] In some embodiments, an anti-FGFR2-IIIb antibody binds FGFR2-IIIb with higher affinity than FGFR2-IIIc or does not bind FGFR2-IIIc in a detectable manner; inhibits FGF2 binding to human FGFR2; and/or inhibits FGF7 binding to human FGFR2. Antibody binding to FGFR2 and inhibition of binding between FGFR2 and FGF can be assessed, for example, using ELISA assays as described in US Pat. -17600. In some embodiments, the antibody induces ADCC activity, and in some embodiments, has increased ADCC activity, for example, as described in WO 2015/-17600. For example, ADCC activity can be determined as described in Example 3 of WO 2015/-17600. In some embodiments, the antibody can inhibit human tumor growth in a mouse model, for example, as shown in Example 1 of International Application No. PCT/US2016/063332. In some embodiments, an anti-FGFR2-IIIb antibody is capable of increasing the number of one or more PD-L1 positive cells, NK cells, CD3+ T cells, CD4+ T cells, CD8+ T cells, and macrophages in tumor tissue in a mouse tumor model according to compared with the control, for example, as described in example 2 of the international application No. PCT/US2016/063332.

Afucosylated anti-FGFR2 antibodies

[0094] In some embodiments, anti-FGFR2 antibodies, e.g., anti-FGFR2-IIIb antibodies as described above, have a carbohydrate structure that lacks fucose attached (directly or indirectly) to the Fc region (i.e., afucosylated antibodies), i.e., the antibodies are afucosylated. In some embodiments, the afucosylated antibody is an IgG1 or IgG3 antibody that lacks fucose at position Asn297.

[0095] In the context of this document, antibodies are considered afucosylated when a plurality of such antibodies contains at least 95% afucosylated antibodies. The amount of fucose can be determined by calculating the average amount of fucose in the sugar chain in Asn297 relative to the sum of all glycostructures attached to Asn297 ( eg complex, hybrid and high-mannose structures). Non-limiting examples of methods for detecting fucose in an antibody include MALDI-TOF mass spectrometry ( see e.g. WO 2008/077546), HPLC measurement of released fluorescently labeled oligosaccharides ( see e.g. Schneider et al., “N-Glycan analysis of monoclonal antibodies and other glycoproteins using UHPLC with fluorescence detection,” Agilent Technologies, Inc. (2012); Lines, J. Pharm. Biomed. Analysis , 14: 601-608 (1996); Takahasi, J. Chrom ., 720: 217-225 (1996)), measurement by capillary electrophoresis of released fluorescently labeled oligosaccharides ( see e.g. Ma et al., Anal. Chem. , 71: 5185-5192 (1999)) and HPLC with pulsed amperometric detection to measure composition of monosaccharides ( see, for example, Hardy, et al., Analytical Biochem. , 170: 54-62 (1988)).

[0096] Asn297 refers to an asparagine residue located approximately at position 297 in the Fc region (EU numbering of residues in the Fc region); however, in a given antibody sequence, Asn297 can also be located approximately ±3 amino acids upstream or downstream of position 297, i.e. between positions 294 and 300, due to minor sequence variations in antibodies. In the anti-FGFR2-IIIb antibody described herein, Asn297 is located in the QY N ST sequence (positions 292-296 of SEQ ID NO: 2) and is bolded and underlined in the sequence table shown below, SEQ ID NO: 2.

[0097] Fucosylation variants may have improved ADCC function. See, for example, US Patent Publications No. US 2003/0157108 (Presta, L.); US 2004/0093621 (Kyowa Hakko Kogyo Co., Ltd). Examples of publications relating to "afucosylated" or "fucose-deficient" antibodies include: US 2003/0157108; WO2000/61739; WO 2001/29246; US 2003/0115614; US 2002/0164328; US 2004/0093621; US 2004/0132140; US 2004/0110704; US 2004/0110282; US 2004/0109865; WO2003/085119; WO2003/084570; WO2005/035586; W02005/035778; WO2005/053742; WO2002/031140; Okazaki et al. J. Mol. biol . 336:1239-1249 (2004); Yamane-Ohnuki et al. Biotech. Bioeng . 87:614 (2004). Examples of cell lines capable of producing afucosylated antibodies include Lec13 CHO cells lacking protein fucosylation (Ripka et al. Arch. Biochem. Biophys. 249: 533-545 (1986); US Patent Application No. US 2003/0157108 A1, Presta, L; and WO 2004/056312 A1, Adams et al ., especially in Example 11), and knockout cell lines, such as cell lines lacking a functional alpha-1,6-fucosyltransferase gene, FUT8, e.g., CHO knockout cells ( cf. eg Yamane-Ohnuki et al Biotech Bioeng 87:614 (2004); Kanda, Y et al Biotechnol Bioeng 94(4):680-688 (2006); and WO2003/085107) .

[0098] Anti-FGFR2 antibodies herein may also contain bisected oligosaccharides, for example, in which a two-antennary oligosaccharide attached to the Fc region of the antibody is bisected by GlcNAc. Such antibodies may have reduced fucosylation and/or improved ADCC function. Examples of such antibodies are described, for example, in WO 2003/011878 (Jean-Mairet et al .); U.S. Patent No. 6,602,684 (Umana et al .); and US 2005/0123546 (Umana et al .). In some embodiments, anti-FGFR2 antibodies have at least one galactose residue in the oligosaccharide attached to the Fc region. Such antibodies may have improved CSC function. Such antibodies are described, for example, in WO 1997/30087 (Patel et al .); WO 1998/58964 (Raju, S.); and WO 1999/22764 (Raju, S.).

[0099] In some embodiments, an afucosylated anti-FGFR2 antibody mediates ADCC in the presence of human effector cells more efficiently than an antibody with the same amino acid sequence that contains fucose. Typically, ADCC activity can be determined using the in vitro ADCC assay disclosed in US Patent Publication No. 2015-0050273 A1, however, other assays or methods for determining ADCC activity, such as in an animal model, etc., can also be used.

[00100] In some embodiments, an anti-FGFR2 antibody comprises the heavy and light chain sequences of SEQ ID NOs: 2 and 3. In some embodiments, an antibody comprising the heavy and light chain sequences of SEQ ID NOs: 2 and 3 is afucosylated.

Typical antibody constant regions

[00101] In some embodiments, the anti-FGFR2 described herein comprises one or more human constant regions. In some embodiments, the human heavy chain constant region is an isotype selected from IgA, IgG, and IgD. In some embodiments, the human light chain constant region has an isotype selected from κ and λ.

[00102] In some embodiments, an antibody described herein comprises a human IgG constant region. In some embodiments, when an effector function is desired, an antibody comprising a human IgG1 heavy chain constant region or a human IgG3 heavy chain constant region is selected. In some embodiments, an antibody described herein contains a human IgG1 constant region. In some embodiments, an antibody described herein contains a human IgG1 constant region wherein N297 is not fucosylated. In some embodiments, an antibody described herein comprises a human IgG1 constant region and a human κ light chain.

[00103] In the present description and claims, unless explicitly indicated or known to a person skilled in the art, the numbering of residues in the immunoglobulin heavy chain corresponds to the EU index in accordance with the nomenclature of Kabat et al ., Sequences of Proteins of Immunological Interest , 5 ^th Ed . Public Health Service, National Institutes of Health, Bethesda, Md. (1991), the contents of which are expressly incorporated herein by reference. "EU index according to Kabat" refers to the EU residue numbering of a human IgG1 antibody.

[00104] In certain embodiments, an antibody of the invention comprises a variant Fc region having at least one amino acid substitution compared to the Fc region of a wild-type IgG or wild-type antibody. In some embodiments, the Fc region variant has two or more amino acid substitutions in the Fc region of the wild-type antibody. In some embodiments, the variant Fc region has three or more amino acid substitutions in the Fc region of the wild-type antibody. In certain embodiments, a variant Fc region has at least one, two, or three or more Fc region amino acid substitutions described herein. In certain embodiments, the variant Fc region herein will have at least about 80% homology to the native sequence Fc region and/or to the Fc region of the parent antibody. In certain embodiments, the variant Fc region herein will have at least about 90% homology to the native sequence Fc region and/or to the Fc region of the parent antibody. In certain embodiments, the variant Fc region herein will have at least about 95% homology to the native sequence Fc region and/or to the Fc region of the parent antibody.

[00105] In certain embodiments, an antibody provided herein is modified to increase or decrease the degree to which the antibody is glycosylated. The addition or removal of glycosylation sites to an antibody can conveniently be accomplished by changing the amino acid sequence such that one or more glycosylation sites are created or removed.

[00106] When an antibody contains an Fc region, the carbohydrate attached to it can be changed. Native antibodies produced by mammalian cells typically contain a branched, dual-antennary oligosaccharide that is typically N-linked to the Asn297 domain of the CH2 Fc region. See, for example, Wright et al. TIBTECH 15:26-32 (1997). The oligosaccharide may include various carbohydrates, for example, mannose, N-acetylglucosamine (GlcNAc), galactose and sialic acid, as well as fucose attached to GlcNAc in the "stem" of the two-antennary structure of the oligosaccharides. In some embodiments, modifications can be made to the oligosaccharide in an antibody of the invention to create antibodies with certain improved properties.

[00107] Antibodies can also have amino-terminal leader extensions. For example, one or more amino acid residues of the amino-terminal leader sequence are present at the amino-terminus of any one or more heavy or light chains of an antibody. A typical amino-terminal leader extension contains or consists of three VHS amino acid residues present in one or both of the antibody light chains.

[00108] The in vivo or serum half-life of high-affinity human FcRn-binding polypeptides can be analyzed, for example , in transgenic mice, humans, or non-human primates administered polypeptides with a variant Fc region. See also, for example , Petkova et al . International Immunology 18(12):1759-1769 (2006).

Typical chimeric antibodies

[00109] In certain embodiments, an anti-FGFR2 antibody provided herein is a chimeric antibody. Some chimeric antibodies are described, for example in US Pat. No. 4,816,567; and Morrison et al ., (1984) Proc. Natl. Acad. sci. USA , 81: 6851-6855 (1984)). In one example, a chimeric antibody contains a non-human variable region ( eg , a variable region derived from a mouse, rat, hamster, rabbit, or non-human primate such as a monkey) and a human constant region. In a further example, a chimeric antibody is a "class-switched" antibody in which the class or subclass has been changed from the parent antibody. Chimeric antibodies include their antigen-binding fragments.

[00110] Non-limiting exemplary chimeric antibodies include anti-FGFR2 chimeric antibodies comprising the heavy chain HVR1, HVR2 and HVR3 and/or light chain HVR1, HVR2 and HVR3 sequences described herein.

[00111] In some embodiments, the chimeric antibody described herein contains one or more human constant regions. In some embodiments, the human heavy chain constant region is an isotype selected from IgA, IgG, and IgD. In some embodiments, the human light chain constant region has an isotype selected from κ and λ. In some embodiments, a chimeric antibody described herein contains a human IgG constant region. In some embodiments, a chimeric antibody described herein comprises a human IgG4 heavy chain constant region. In some embodiments, a chimeric antibody described herein comprises a human IgG4 constant region and a human κ light chain.

[00112] As noted above, whether an effector function is needed or not may depend on the particular treatment chosen for the antibody. Thus, in some embodiments, when an effector function is desired, a chimeric antibody comprising a human IgG1 heavy chain constant region or a human IgG3 heavy chain constant region is selected. In some embodiments, when effector function is not desired, a chimeric antibody containing a human IgG4 or IgG2 heavy chain constant region is selected. In some embodiments, the chimeric antibody described herein contains a human IgG1 constant region wherein N297 is not fucosylated. In some embodiments, the chimeric antibody described herein comprises a human IgG1 constant region and a human κ light chain.

Typical humanized antibodies

[00113] In some embodiments, humanized antibodies that bind FGFR2 are used. Humanized antibodies are useful as therapeutic molecules because humanized antibodies reduce or abolish the human immune response to non-human antibodies (such as the human anti-mouse antibody (HAMA) response), which can lead to an immune response to an antibody-based therapeutic agent and reduce the effectiveness of a therapeutic agent. facilities.

[00114] In certain embodiments, the chimeric antibody is a humanized antibody. Typically, a non-human antibody is humanized to reduce immunogenicity in humans while retaining the specificity and affinity of the parent non-human antibody. Typically, a humanized antibody contains one or more variable domains in which the HVRs or CDRs (or portions thereof) are derived from a non-human antibody and the FRs (or portions thereof) are derived from human antibody sequences. The humanized antibody will optionally also contain at least a portion of the human constant region. In some embodiments, some FR residues in a humanized antibody are replaced with corresponding residues from a non-human antibody ( eg, the antibody from which the HVR residues are derived), eg, to restore or improve the specificity or affinity of the antibody.

[00115] Humanized antibodies and methods for their preparation are discussed, for example, in Almagro and Fransson, (2008) Front. biosci . 13: 1619-1633, and are further described in, for example , Riechmann et al ., (1988) Nature 332:323-329; Queen et al ., (1989) Proc. Natl Acad. sci. USA 86: 10029-10033; U.S. Patent Nos. 5,821,337; 7,527,791; 6,982,321; and 7,087,409; Kashmiri et al ., (2005) Methods 36:25-34 (SDR Grafting Description (a-CDR)); Padlan, (1991) Mol. Immunol. 28:489-498 (description "surface change");Dall'Acqua et al ., (2005) Methods 36:43-60 (description of "FR permutation"); and Osbourn et al ., (2005) Methods 36:61-68 and Klimka et al ., (2000) Br. J. Cancer , 83:252-260 (description of a "guided selection" approach to FR permutation).

[00116] Human framework regions that can be used for humanization include, but are not limited to: framework regions selected using the "best fit" method (see, for example , Sims et al . (1993) J. Immunol. 151: 2296); framework regions derived from the consensus sequence of human antibodies of a particular subgroup of light or heavy chain variable regions (see, e.g. , Carter et al . (1992) Proc. Natl. Acad. Sci. USA , 89:4285; and Presta et al . ( 1993) J. Immunol , 151:2623); mature human framework regions (somatically mutated) or human germline framework regions (see, for example , Almagro and Fransson, (2008) Front. Biosci . 13:1619-1633); and framework regions derived from screening FR libraries (see e.g. Baca et al ., (1997) J. Biol. Chem . 272: 10678-10684 and Rosok et al ., (1996) J. Biol. Chem. 271 : 22611-22618).

[00117] In some embodiments, humanized antibodies comprise one or more human constant regions. In some embodiments, the human heavy chain constant region is an isotype selected from IgA, IgG, and IgD. In some embodiments, the human light chain constant region has an isotype selected from κ and λ.

[00118] In some embodiments, the humanized antibody described herein contains a human IgG constant region. In some embodiments, when an effector function is desired, the antibody comprises a human IgG1 heavy chain constant region or a human IgG3 heavy chain constant region. In some embodiments, a humanized antibody described herein contains a human IgG1 constant region. In some embodiments, the humanized antibody described herein contains a human IgG1 constant region wherein N297 is not fucosylated. In some embodiments, a humanized antibody described herein comprises a human IgG1 constant region and a human κ light chain.

human antibodies

[00119] Human antibodies to FGFR2 can be obtained by any suitable method. Non-limiting exemplary methods include generating human antibodies from transgenic mice that contain human immunoglobulin loci. See, for example , Jakobovits et al., Proc. Natl. Acad. sci. USA 90: 2551-55 (1993); Jakobovits et al., Nature 362: 255-8 (1993); Lonberg et al., Nature 368: 856-9 (1994); and US Patent Nos. 5,545,807; 6 713 610; 6 673 986; 6,162,963; 5 545 807; 6 300 129; 6 255 458; 5 877 397; 5 874 299; and 5 545 806.

[00120] Non-limiting exemplary methods include generating human antibodies using phage display libraries. See, for example, Hoogenboom et al., J. Mol. Biol. 227: 381-8 (1992); Marks et al., J. Mol. Biol. 222:581:-97 (1991) and PCT Publication No. WO 99/10494).

[00121] In some embodiments, the implementation of the human antibody contains one or more human constant regions. In some embodiments, the human heavy chain constant region is an isotype selected from IgA, IgG, and IgD. In some embodiments, the human light chain constant region has an isotype selected from κ and λ. In some embodiments, a human antibody described herein contains a human IgG constant region. In some embodiments, a human antibody described herein comprises a human IgG4 heavy chain constant region. In some such embodiments, the human antibody described herein contains the S241P mutation in the human IgG4 constant region. In some embodiments, a human antibody described herein comprises a human IgG4 constant region and a human κ light chain.

[00122] In some embodiments, when an effector function is desired, a human antibody comprising a human IgG1 heavy chain constant region or a human IgG3 heavy chain constant region is selected. In some embodiments, when effector function is not desired, a human antibody containing a human IgG4 or IgG2 heavy chain constant region is selected. In some embodiments, the humanized antibody described herein contains a human IgG1 constant region wherein N297 is not fucosylated. In some embodiments, a humanized antibody described herein comprises a human IgG1 constant region and a human κ light chain.

Exemplary Antibody Conjugates

[00123] In some embodiments, the anti-FGFR2 antibody is conjugated to a label and/or a cytotoxic agent. In the context of this document, a label is a fragment that facilitates the detection of an antibody and/or facilitates the detection of a molecule to which the antibody binds. Non-limiting examples of labels include, but are not limited to, radioisotopes, fluorescent groups, enzyme groups, chemiluminescent groups, biotin, epitope labels, metal binding labels, etc. A person skilled in the art can select an appropriate label according to the intended application.

[00124] As used herein, a cytotoxic agent is a moiety that reduces the proliferative capacity of one or more cells. A cell has a reduced proliferative capacity when the cell becomes less capable of proliferating, for example, because the cell undergoes apoptosis or otherwise dies, the cell cannot go through the cell cycle and/or cannot divide, the cell differentiates, and so on. Non-limiting typical cytotoxic agents include, but are not limited to, radioisotopes, toxins, and chemotherapeutic agents. The person skilled in the art can select the appropriate cytotoxic agent according to the intended use.

[00125] In some embodiments, the label and/or cytotoxic agent is conjugated to the antibody using in vitro chemical methods. Non-limiting illustrative chemical conjugation methods are known in the art and include services, methods, and/or reagents commercially available from, for example, Thermo Scientific Life Science Research Produces (formerly Pierce; Rockford, IL, USA), Prozyme (Rockford, Illinois, USA), Prozyme (Rockford, Illinois, USA). Hayward, CA, USA), SACRI Antibody Services (Calgary, Canada), AbD Serotec (Raleigh, NC, USA), and others. In some embodiments, when the label and/or cytotoxic agent is a polypeptide, the label and/or cytotoxic agent can be expressed from a single expression vector together with at least one antibody chain to produce a polypeptide containing the label and/or cytotoxic agent fused to the antibody chain. The person skilled in the art can select the appropriate method for conjugating the label and/or cytotoxic agent to the antibody according to the intended use.

Nucleic acid molecules encoding antibodies

[00126] Proposed nucleic acid molecules containing polynucleotides that encode one or more chains of the antibody. In some embodiments, the nucleic acid molecule comprises a polynucleotide that encodes for the heavy chain or light chain of an antibody. In some embodiments, the nucleic acid molecule contains both a polynucleotide that encodes a heavy chain and a polynucleotide that encodes a light chain of an antibody. In some embodiments, the first nucleic acid molecule contains a first polynucleotide that encodes a heavy chain, and the second nucleic acid molecule contains a second polynucleotide that encodes a light chain.

[00127] In some such embodiments, the heavy chain and light chain are expressed from a single nucleic acid molecule or from two separate nucleic acid molecules as two separate polypeptides. In some embodiments, for example, when the antibody is a scFv, one polynucleotide encodes a single polypeptide containing both the heavy chain and the light chain linked together.

[00128] In some embodiments, the implementation of the polynucleotide encoding the heavy chain or light chain of the antibody contains a nucleotide sequence that encodes a leader sequence that, when translated, is at the N-terminus of the heavy chain or light chain. As discussed above, the leader sequence may be a native heavy or light chain leader, or may be another heterologous leader sequence.

[00129] Nucleic acid molecules can be constructed using recombinant DNA techniques generally accepted in the art. In some embodiments, the nucleic acid molecule is an expression vector that is suitable for expression in a selected host cell.

Expression and production of antibodies

Vectors

[00130] Vectors are provided that contain polynucleotides that encode heavy chains and/or light chains of antibodies. Also provided are vectors containing polynucleotides that encode heavy chains and/or light chains of antibodies. Such vectors include, but are not limited to, DNA vectors, phage vectors, viral vectors, retroviral vectors, and the like. In some embodiments, the vector comprises a first polynucleotide sequence encoding a heavy chain and a second polynucleotide sequence encoding a light chain. In some embodiments, the heavy chain and light chain are expressed from the vector as two separate polypeptides. In some embodiments, the heavy chain and light chain are expressed as part of a single polypeptide, such as when the antibody is a scFv.

[00131] In some embodiments, the first vector contains a polynucleotide that encodes a heavy chain, and the second vector contains a polynucleotide that encodes a light chain. In some embodiments, the first vector and the second vector are transfected into host cells in similar amounts (such as similar molar amounts or similar mass amounts). In some embodiments, a molar or mass ratio between 5:1 and 1:5 of the first vector and the second vector is transfected into host cells. In some embodiments, a weight ratio between 1:1 and 1:5 is used for the heavy chain encoding vector and the light chain encoding vector. In some embodiments, a 1:2 weight ratio is used for the heavy chain encoding vector and the light chain encoding vector.

[00132] In some embodiments, a vector is selected that is optimized for expression of polypeptides in CHO cells or cells derived from CHO or NSO cells. Examples of such vectors are described, for example, in Running Deer et al., Biotechnol. Prog. 20:880-889 (2004).

[00133] In some embodiments, the vector is selected for in vivo expression of antibody heavy chains and/or antibody light chains in animals, including humans. In some such embodiments, expression of the polypeptide is under the control of a promoter that functions in a tissue-specific manner. For example, liver-specific promoters are described, for example, in PCT Publication No. WO 2006/076288.

Host cells

[00134] In various embodiments, the heavy chains and/or light chains of antibodies can be expressed in prokaryotic cells, such as bacterial cells; or in eukaryotic cells such as fungal (such as yeast), plant cells, insect cells and mammalian cells. Such expression can be carried out, for example, in accordance with procedures known in the art. Typical eukaryotic cells that can be used to express polypeptides include, but are not limited to, COS cells, including COS 7 cells; cells 293, including cells 293-6E; CHO cells, including CHO-S and DG44 cells; PER.C6® cells (Crucell); and NSO cells. In some embodiments, heavy chains and/or light chains of antibodies can be expressed in yeast. See, for example, US Publication No. US 2006/0270045 A1. In some embodiments, a particular eukaryotic host cell is selected based on its ability to perform the desired post-translational modifications to the heavy chains and/or light chains of the antibody. For example, in some embodiments, CHO cells produce polypeptides that have a higher level of sialylation than the same polypeptide produced in 293 cells.

[00135] Introduction of one or more nucleic acids into the desired host cell can be carried out by any method, including, but not limited to, calcium phosphate transfection, DEAE-dextran mediated transfection, cationic lipid mediated transfection, electroporation, transduction, infection, and etc. Non-limiting examples of methods are described, for example, in Sambrook et al., Molecular Cloning, A Laboratory Manual, ^3rd ed. Cold Spring Harbor Laboratory Press (2001). Nucleic acids can be transiently or stably transfected into desired host cells according to any suitable method.

[00136] In some embodiments, one or more polypeptides can be produced in vivo in an animal that has been engineered or transfected with one or more nucleic acid molecules encoding the polypeptides, in accordance with any suitable method.

Purification of antibodies

[00137] Antibodies can be purified by any suitable method. Such methods include, but are not limited to, the use of affinity matrices or hydrophobic interaction chromatography. Suitable affinity ligands include antigen and ligands that bind antibody constant regions. For example, a protein A column, a protein G column, a protein A/G column, or an immobilized antibody column can be used to bind the constant region and to purify the antibody. Hydrophobic interaction chromatography, such as a butyl or phenyl column, may also be suitable for the purification of some polypeptides. Many methods for purifying polypeptides are known in the art.

Cell-free production of antibodies

[00138] In some embodiments, the antibody is produced in a cell-free system. Non-limiting examples of cell-free systems are described, for example, in Sitaraman et al., Methods Mol. Biol. 498: 229-44 (2009); Spirin, Trends Biotechnol. 22:538-45 (2004); Endo et al., Biotechnol. Adv. 21:695-713 (2003).

Modified FOLFOX6

[00139] A modified FOLFOX6 (mFOLFOX6) chemotherapy regimen includes a regimen in which a combination of oxaliplatin (eg, Eloxatin®), leucovorin (eg, calcium leucovorin or folinic acid), and 5-fluorouracil (5-FU) is administered intravenously alternately for approximately 2 - diurnal period. Modified FOLFOX6 has been used as a first line therapy for the treatment of advanced gastric cancer. A phase 3 randomized trial comparing mFOLFOX6 with 5FU/LV/cisplatin (FLP) in 220 patients with gastric cancer showed a statistically non-significant improvement in time to progression; however, mFOLFOX6 was associated with a significant reduction in grade 3/4 adverse events, including neutropenia, anemia, and peripheral neuropathy. (Al-Batran et al., J. Clin. Oncol. 26: 1435-42 (2008).) Subsequent studies confirmed the safety and efficacy of mFOLFOX6 in advanced gastric cancer. (B. Keam, BMC Cancer , 8:148 (2008).)

[00140] In some embodiments, the combination of oxaliplatin (e.g., Eloxatin®), leucovorin (e.g., calcium leucovorin or folinic acid), and 5-fluorouracil (5-FU) is administered by intravenous infusion or intravenous bolus injection over about 2-8 hours, followed by an additional infusion of 5-FU by intravenous infusion over approximately 44-48 hours. In some embodiments, the mFOLFOX6 regimen includes: administration of oxaliplatin on the 1st day at a dose of 50-100 mg/m ² IV, for example, for 2 hours, then the administration of leucovorin on the 1st day at a dose of 100-400 mg/day. m ² IV, for example, for 2 hours, then the introduction of 5-FU at a dose of 100-400 mg/m ² using an IV bolus injection or IV infusion, all on the 1st day, followed by additional infusion of 5-FU at a dose of 2000-2500 mg/m ² within 44-48 hours, for example 46 hours. In some embodiments, the mFOLFOX6 regimen includes: administration of oxaliplatin on the 1st day at a dose of 75-100 mg/m ² IV, for example, for 2 hours, then the administration of leucovorin on the 1st day at a dose of 200-400 mg/day. m ² IV, for example, for 2 hours, then the introduction of 5-FU at a dose of 200-400 mg / m ² using an IV bolus injection or IV infusion, all on the 1st day, followed by additional infusion of 5-FU at a dose of 2200-2400 mg/m ² within 44-48 hours, for example 46 hours. In some embodiments, the mFOLFOX6 regimen includes: administration of oxaliplatin on the 1st day at a dose of 75-90 mg/m ² IV, for example, for 2 hours, then the administration of leucovorin on the 1st day at a dose of 300-400 mg/day. m ² IV, for example, for 2 hours, then the introduction of 5-FU at a dose of 300-400 mg/m ² using an IV bolus injection or IV infusion, all on the 1st day, followed by additional infusion of 5-FU at a dose of 2200-2400 mg/m ² within 44-48 hours, for example 46 hours.

[00141] In some embodiments, the mFOLFOX6 regimen includes: administration of oxaliplatin on day 1 at a dose of 85 mg/m ² IV, for example, for 2 hours, then the administration of leucovorin on day 1 at a dose of 400 mg/m ² IV, for example, over 2 hours, followed by 5-FU at 400 mg/m ² by IV bolus injection or IV infusion, all on day 1, followed by an additional infusion of 5- FU at a dose of 2400 mg/m ² within 44-48 hours, for example 46 hours. For example, an initial dose for mFOLFOX6 as a first-line therapy for gastric cancer may include 85 mg/m ² oxaliplatin, 350 mg calcium folinate (folinic acid), 400 mg/m ² doses of fluorouracil followed by an infusion of 2400 mg/m ² fluorouracil within 46 hours.

[00142] In some embodiments, the mFOLFOX6 regimen may be administered once every 10-21 days, for example, once every 10-15 days, once every 10 days, once every 11 days, once every 12 days, once every 13 days, once every 14 days, once every 15 days, once every 16 days, once every 17 days, once every 18 days, once every 19 days, once every 20 days or once every 21 days.

[00143] In some embodiments, mFOLFOX6 may be administered once every "2 weeks", which in the context of the general dosing regimen herein means once every 14 days plus or minus 3 days, or once every 11-17 days.

Therapeutic compositions and methods.

Ways to treat cancer

[00144] In some embodiments, methods of treating cancer are provided, comprising administering an effective amount of an anti-FGFR2 antibody, such as an anti-FGFR2-IIIb antibody, as described herein, in combination with a modified FOLFOX6 (mFOLFOX6) chemotherapy regimen. In some embodiments, the cancer is gastrointestinal (GI) cancer, such as gastric cancer, colorectal cancer, and pancreatic adenocarcinoma. In some embodiments, the cancer is inoperable, locally advanced, or metastatic gastric cancer.

[00145] In some embodiments of the methods, the anti-FGFR2-IIIb antibody is administered at a dose of 6-15 mg/kg, 10-15 mg/kg, 6 mg/kg, 7 mg/kg, 8 mg/kg, 9 mg/kg, 10 mg/kg, 11 mg/kg, 12 mg/kg, 13 mg/kg, 14 mg/kg or 15 mg/kg. In some embodiments, the anti-FGFR2-IIIb antibody is administered once every 7-21 days, once every 7-15 days, once every 7-10 days, once every 10-14 days, once every 11-17 days, once in 12-16 days, once in 13-15 days, once in 7 days, once in 8 days, once in 9 days, once in 10 days, once in 11 days, once in 12 days, once every 13 days, once every 14 days, once every 15 days, once every 16 days, once every 17 days, once every 18 days, once every 19 days, once every 20 days, or once every 21 days. In some embodiments, the anti-FGFR2-IIIb antibody may be administered once every 2 weeks, ie once every 14 days plus or minus 3 days, or once every 11-17 days.

[00146] In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dosage regimen of 6-15 mg/kg every 2 weeks. In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dosage regimen of 6-15 mg/kg every 13-15 days. In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dosage regimen of 6-15 mg/kg every 14 days. In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dosage regimen of 6, 10, or 15 mg/kg every 2 weeks. In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dosage regimen of 6, 10, or 15 mg/kg every 13-15 days. In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dosage regimen of 6, 10, or 15 mg/kg every 14 days.

[00147] In some embodiments, a dosing regimen is used in which two doses are administered 2 weeks apart and an intermediate booster dose is administered in the time period between the two doses, the intermediate booster dose being lower than the two doses. Dosing in this manner may help maintain the antibody in the circulation at a reasonable or relatively stable concentration over an extended period of time. For example, if post-dose circulating antibody concentration drops to a trough approximately one week after administration, then a lower booster dose at or near that point followed by a regular dose approximately one week after the booster dose may help stabilize the total circulating antibody concentration at over an extended period of time and avoid drops in concentration between doses.

[00148] Accordingly, in some embodiments, the anti-FGFR2-IIIb antibody is administered at a dosage regimen of 6-15 mg/kg every 2 weeks, and an intermediate booster dose that is lower than the 6-15 mg/kg dose is administered through 1 week (i.e. 7 plus or minus 2 days or 5-9 days) after the first of two 6-15 mg/kg doses and 1 week (i.e. 5-9 days) before the second of two 6-15 mg doses /kg. In some such embodiments, the booster dose is 3-8 mg/kg. In some embodiments, the booster dose is half of the immediately preceding dose and the subsequent dose. In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dosing schedule of 6-15 mg/kg every 2 weeks and an intermediate booster dose of 3-8 mg/kg is administered 6-8 days after the first of two doses of 6-15 mg/kg and 6-8 days prior to the second of two doses of 6-15 mg/kg. In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dosing schedule of 10-15 mg/kg every 2 weeks and an intermediate booster dose of 5-8 mg/kg is administered 6-8 days after the first of two doses of 10-15 mg/kg and 6-8 days prior to the second of two doses of 10-15 mg/kg. In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dosing regimen of 15 mg/kg every 2 weeks, and an intermediate booster dose of 7-8 mg/kg is administered 6-8 days after the first two doses of 15 mg/kg and 6-8 days days prior to the second of two doses of 15 mg/kg. In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dosing schedule of 15 mg/kg every 13-15 days, and an intermediate booster dose of 7-8 mg/kg is administered 6-8 days after the first of two 15 mg/kg doses and beyond 6-8 days prior to the second of two doses of 15 mg/kg. In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dosing schedule of 15 mg/kg every 14 days, and an intermediate booster dose of 7-8 mg/kg is administered 6-8 days after the first of two 15 mg/kg doses and 6- 8 days prior to the second of two doses of 15 mg/kg. In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dosing schedule of 15 mg/kg every 14 days, and an intermediate booster dose of 7-8 mg/kg is administered 7 days after the first of two 15 mg/kg doses and 7 days prior to administration the second of two doses of 15 mg/kg. In some of the above embodiments, the booster dose is administered only once, for example, only between the first and second doses of the antibody to the patient. In other embodiments, it is administered only twice, eg between the first and second and second and third doses of the antibody.

[00149] In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dosing schedule of 15 mg/kg every 14 days, and an intermediate booster dose of 7.5 mg/kg is administered 7 days after the first of two 15 mg/kg doses and 7 days days prior to the second of two doses of 15 mg/kg. In some embodiments, the anti-FGFR2-IIIb antibody is administered at a dose of 15 mg/kg once every 14 days, starting on the 1st and 7 days after the first administration of the anti-FGFR2-IIIb antibody (i.e., on the 8th day) , the antibody to FGFR2-IIIb is administered at a booster dose of 7.5 mg/kg. In some such embodiments, the 7.5 mg/kg booster dose is administered only once, eg, only between the first and second administrations of the 15 mg/kg antibody.

[00150] The anti-FGFR2-IIIb antibody and mFOLFOX6 can be administered simultaneously, for example, on the same day, for example, with the administration of the antibody by intravenous infusion prior to the start of the mFOLFOX6 regimen, or they can be administered sequentially, for example, on different days. In some embodiments, mFOLFOX6 is administered at least once or at least twice prior to initiation of anti-FGFR2-IIIb antibody treatment. In some embodiments, both the antibody and the mFOLFOX6 regimen are administered once every 7-21 days, once every 7-15 days, once every 7-10 days, once every 10-14 days, once every 11-17 days. days, once every 12-16 days, once every 13-15 days, once every 7 days, once every 8 days, once every 9 days, once every 10 days, once every 11 days, once in 12 days, once in 13 days, once in 14 days, once in 15 days, once in 16 days, once in 17 days, once in 18 days, once in 19 days, once in 20 days or once every 21 days. In some embodiments, the anti-FGFR2-IIIb antibody and mFOLFOX6 regimen may be administered once every 2 weeks, ie once every 14 days plus or minus 3 days, or once every 11-17 days.

[00151] In some embodiments, an anti-FGFR2-IIIb antibody comprises a heavy chain and a light chain variable region, wherein the heavy chain variable region comprises:

(i) HVR-H1 containing the amino acid sequence of SEQ ID NO: 6;

(ii) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; And

(iii) HVR-H3 containing the amino acid sequence of SEQ ID NO: 8;

and the variable region of the light chain contains:

(iv) HVR-L1 containing the amino acid sequence of SEQ ID NO: 9;

(v) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; And

(vi) HVR-L3 containing the amino acid sequence of SEQ ID NO: 11;

and anti-FGFR2-IIIb antibody is administered intravenously at a dose of 10-15 mg/kg followed by the introduction of mFOLFOX6, including the introduction of 85 mg/m ² oxaliplatin, 400 mg/m ² leucovorin and 400 mg/m ² 5-fluorouracil (5-FU) by intravenous infusion or intravenous bolus injection followed by the introduction of 2400 mg/m ² 5-FU by intravenous infusion within 44-48 hours; and an antibody to FGFR2-IIIb and mFOLFOX6 is administered every 2 weeks.

[00152] In some embodiments, the subject has gastric cancer containing an FGFR2 gene amplification, while in some embodiments, the cancer does not contain an FGFR2 amplification. In some embodiments, fluorescence in situ hybridization (FISH) is used to evaluate gene amplification, for example, with probes to the FGFR2 gene locus and chromosome 10 centromere. ) > 3. In some embodiments, the FGFR2 amplification comprises a ratio of FGFR2: CEN10 ≥2. However, in other embodiments, the FGFR2 level includes a FGFR2:CEN10 ratio of 1 to 2, indicating that FGFR2 is not amplified.

[00153] In some embodiments, the subject has gastric cancer overexpressing FGFR2 or overexpressing FGFR2-IIIb. In some embodiments, the cancer overexpresses FGFR2-IIIb to a greater extent than FGFR2-IIIc. In some embodiments, the cancer does not include gene amplification, however, FGFR2-IIIb is overexpressed, while in other embodiments, the cancer includes both FGFR2 gene amplification and FGFR2-IIIb overexpression. In some embodiments, a cancer involving FGFR2 amplification expresses FGFR2-IIIb at a normalized level that is greater than 2, 3, 5, or 10 times the normalized level of FGFR2-IIIc expression. In some embodiments, expression levels are normalized to GUSB. In some embodiments, overexpression is mRNA overexpression. In some embodiments, overexpression is protein overexpression. In some embodiments, a point mutation or translocation may cause FGFR2 to be overexpressed.

[00154] In some embodiments, FGFR2 or FGFR2-IIIb overexpression is determined by immunohistochemistry (IHC). For example, overexpression can be determined by IHC signal 1+, 2+ or 3+ in at least 10% of tumor cells, for example, in at least 20%, 30%, 40% or 50% of tumor cells. For example, in some such embodiments, patients to be treated may have, for example, an IHC signal for FGFR2-IIIb 2+ or 3+ in at least 10% of the tumor cells (eg, cell membranes). In some embodiments, the patient may have a 3+ signal in at least 10% of the tumor cells. In some embodiments, the patient may have at least a 1+ signal in at least 10% of the tumor cells.

[00155] In some embodiments, FGFR2 or FGFR2-IIIb overexpression may be indicated by a "H score". To determine the H value, the first intensity of membrane staining for cells in a fixed field can be determined, for example via IHC, to give values of 0, 1+, 2+, or 3+, and the H value can be calculated using the formula below: 1x (% cells imaged at 1+ IHC intensity) + 2x (% of cells imaged at 2+ IHC intensity) + 3x (% of cells imaged at 3+ IHC intensity). Theoretically, the H-value can range from 0 to 300 and be equal to 300 if all cells in the field of view have IHC 3+ staining. In some embodiments, the patient to be treated has a baseline H score for FGFR2, such as FGFR2-IIIb, >20, such as >30, >40, >50, or >100, or in the range of 20-300, 20-100, 20-50, 20-40 or 20-30. In some embodiments, the patient has an H score >10 or is in the range of 10-20 or 15-20. In other embodiments, the patient has an H score of 0-10, which may indicate under-expression.

[00156] In some embodiments, a cancer, such as gastric cancer, has already been found to overexpress FGFR2-IIIb and/or carry an amplification of the FGFR2 gene. In other embodiments, the methods described herein evaluate either FGFR2IIIb expression or FGFR2 gene amplification status or both prior to treatment, e.g., to determine whether treatment with an anti-FGFR2-IIIb antibody is warranted. In some embodiments, the methods described herein are used to treat gastric cancer that has been determined to (a) overexpress FGFR2-IIIb as indicated by an IHC signal of 2+ or 3+ in at least 10% of tumors. cells and/or (b) amplification of the FGFR2 gene in tsDNA is observed. In some embodiments, the methods described herein are used to treat gastric cancer that has been determined to (a) overexpress FGFR2-IIIb as indicated by an IHC 3+ signal in at least 10% of the tumor cells and/ or (b) there is an amplification of the FGFR2 gene in ctDNA.

Routes of administration, carriers and additional pharmaceutical compositions

[00157] In various embodiments, antibodies can be administered in vivo by various routes, including, but not limited to, oral, intra-arterial, parenteral, intranasal, intravenous, intramuscular, intracardiac, intraventricular, intratrachial, buccal, rectal, intraperitoneal, intradermal, topical, transdermal and intrathecal, or otherwise by implantation or inhalation. The antibodies in question may be formulated in solid, semi-solid, liquid, or gaseous forms; including, but not limited to, tablets, capsules, powders, granules, ointments, solutions, suppositories, enemas, injections, inhalants, and aerosols. An antibody-encoding nucleic acid molecule can be coated onto gold microparticles and delivered intradermally using a particle bombardment device or "gene gun" as described in the literature (see, for example, Tang et al., Nature 356:152-154 ( 1992)). The appropriate composition and route of administration may be selected according to the intended use.

[00158] In various embodiments, compositions containing antibodies are provided in formulations with a wide range of pharmaceutically acceptable carriers (see, for example, Gennaro, Remington: The Science and Practice of Pharmacy with Facts and Comparisons: Drugfacts Plus , ^20th ed. ( 2003); Ansel et al., Pharmaceutical Dosage Forms and Drug Delivery Systems, ^7th ed., Lippencott Williams and Wilkins (2004); Kibbe et al., Handbook of Pharmaceutical Excipients, ^3rd ed., Pharmaceutical Press (2000)) . Various pharmaceutically acceptable carriers are available, including diluents, excipients, and diluents. In addition, various pharmaceutically acceptable adjuvants are also available, such as pH adjusting and buffering agents, tonicity adjusting agents, stabilizers, wetting agents, and the like. Non-limiting examples of carriers include saline, buffered saline, dextrose, water, glycerol, ethanol, and combinations thereof.

[00159] Compositions comprising an anti-FGFR2 antibody described herein and one or more of the chemotherapeutic agents mFOLFOX 6, oxaliplatin, leucovorin, and 5-FU described herein are also provided herein. In some embodiments, the FGFR2 inhibitor and chemotherapeutic agents are contained, for example, in separate containers or in separate compartments of the same container such that they do not mix with each other. In some embodiments, the implementation of the compositions contain instructions for use, such as instructions for use in the treatment of cancer.

EXAMPLES

[00160] The examples discussed below are only intended to illustrate the invention and should not be construed as limiting the invention in any way. The examples do not imply that the experiments below represent all or the only experiments performed.

Example 1 Randomized, double-blind, placebo-controlled phase 3 study of anti-FGFR2-IIIb antibody in combination with modified FOLFOX6 in patients with previously untreated advanced gastric or gastroesophageal cancer, preceded by a phase 1 dose adjustment and a run-in phase for safety assessments

Summary of the content of the protocol

[00161] The following protocol will be used in up to 250 different research centers around the world. The study will be in two parts, part 1: a phase 1 dose titration study, an introductory phase for safety evaluation, and part 2: a phase 3 study.

[00162] The primary objectives of Part 1 are: (a) to determine the recommended dose (RD) of an anti-FGFR2-IIIb antibody in combination with a fixed-dose infusion of 5-fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) in patients with advanced gastrointestinal (GI) tumors and (b) evaluate the safety profile of increasing doses of anti-FGFR2-IIIb antibody when used in combination with mFOLFOX6 in patients with gastrointestinal tumors. The secondary objectives of Part 1 are (a) to assess the safety and tolerability of long-term exposure to an anti-FGFR2-IIIb antibody when given in combination with mFOLFOX6 in patients with GI tumors, (b) to characterize the pharmacokinetic (PK) profile of an anti-FGFR2-IIIb antibody when given in combination with mFOLFOX6 in patients with gastrointestinal tumors and (c) characterize the immunogenicity of an antibody to FGFR2-IIIb. Part 1 will also characterize the pharmacodynamic (PD) profile of an anti-FGFR2-IIIb antibody when administered in combination with mFOLFOX6 by evaluating exploratory biomarkers in blood and hair follicle samples from patients with gastrointestinal tumors.

[00163] The primary endpoint for Part I: the incidence of adverse events (AEs) of grade 2 or higher associated with an antibody to FGFR2-IIIb, as assessed by the investigator and abnormal results in clinical laboratory tests, defined as dose-limiting toxicity (DLT). Secondary endpoints for Part 1: (a) incidence of AEs, abnormal clinical laboratory findings, corneal and retinal examination findings, and electrocardiogram (ECG) abnormalities, (b) PK parameters of anti-FGFR2- antibody IIIb, such as area under the serum concentration-time curve (AUC), maximum serum concentration (C _max ), minimum serum concentration (C _trough ), clearance (CL), terminal half-life (t _{1/ 2} ), volume of distribution and accumulation factor will be derived from serum drug concentration versus time profiles, where relevant and applicable, and (c) immune response to anti-FGFR2-IIIb antibodies from immunogenicity assays. This part can also examine biomarkers in blood samples and hair follicles.

[00164] The primary goal of Part 2 is to evaluate the clinical benefit of an anti-FGFR2-IIIb antibody when administered in combination with mFOLFOX6 compared to placebo and mFOLFOX6 through a progression-free survival (PFS) analysis in patients with FGFR2b-selective gastric cancer or gastroesophageal cancer (hereinafter referred to as gastric cancer or gastric cancer). Secondary Objectives: (a) to evaluate the clinical benefit of an anti-FGFR2-IIIb antibody when administered in combination with mFOLFOX6 versus placebo and mFOLFOX6 by analyzing overall survival (OS) in patients with FGFR2b-selective gastric cancer, (b) to evaluate the safety and tolerability of anti-FGFR2-IIIb antibody when administered in combination with mFOLFOX6 compared with placebo and mFOLFOX6 in patients with FGFR2b-selective gastric cancer, (c) characterize the PK profile of an antibody to FGFR2-IIIb when administered in combination with mFOLFOX6 in patients with FGFR2b-selective gastric cancer , (d) characterize the immunogenicity of the anti-FGFR2-IIIb antibody, and (e) characterize the PD profile of anti-FGFR2-IIIb antibodies when administered in combination with mFOLFOX6 versus placebo and mFOLFOX6 by analyzing immune cell infiltrate and other exploratory biomarkers in tumor biopsies before and after the course of treatment. The study may also (a) evaluate the clinical benefit of an anti-FGFR2-IIIb antibody when administered in combination with mFOLFOX6 versus placebo and mFOLFOX6 by PFS analysis based on a Blinded Independent Review Committee (BIRC) progression assessment, ( b) evaluate the clinical benefit of an anti-FGFR2-IIIb antibody when administered in combination with mFOLFOX6 compared with placebo and mFOLFOX6 by analyzing the objective response rate (ORR) in patients with FGFR2b-selective gastric cancer, (c) evaluate the clinical benefit of the antibody to FGFR2-IIIb when administered in combination with mFOLFOX6 versus placebo and mFOLFOX6 by ORR analysis based on progression assessment performed by BIRC, (d) evaluate the clinical benefit of an antibody to FGFR2-IIIb when administered in combination with mFOLFOX6 versus placebo and mFOLFOX6 by analyzing one-year OS in patients with FGFR2b-selective gastrointestinal cancer, (e) evaluate the clinical benefit of an anti-FGFR2-IIIb antibody when administered in combination with mFOLFOX6 compared with placebo and mFOLFOX6 by analyzing the duration of response (DOR - duration of response) in patients with FGFR2b-selective GC, (f) investigate the association between FGFR2 status (in tumor tissue and/or blood [cDNA] based biopsy assay, (g) investigate the association between FGFR2 status in tumor tissue and FGFR2 amplification using blood based biopsy assay (cDNA), (h) characterize the PD profile of anti-FGFR2-IIIb antibodies when administered in combination with mFOLFOX6 compared with placebo and mFOLFOX6 by evaluating search biomarkers in blood samples from patients with FGFR2b-selective gastric cancer, and (i) evaluate treatment outcomes by assessment of the patient (PRO - patient reported outcome) and quality of life (QOL - quality of life) in patients with FGFR2b-selective gastric cancer receiving an antibody to FGFR2-IIIb in combination with mFOLFOX6 compared with placebo and mFOLFOX6.

[00165] The endpoints for Part 2 include the primary PFS endpoint, defined as the time from randomization to the date of radiological confirmation of disease progression based on investigator assessment (according to RECIST v.1.1) or death from any cause, whichever comes first, as well as various secondary endpoints. Secondary endpoints include: (a) OS, defined as time from date of randomization to death from any cause, (b) objective response based on investigator assessment of tumor lesions according to RECIST v1.1, (c) incidence of AEs, abnormalities abnormality in clinical laboratory results, corneal and retinal examination results, and electrocardiogram (ECG) abnormalities, (d) PK parameters of anti-FGFR2-IIIb antibody in RD when administered in combination with mFOLFOX6, such as AUC, Cmax _max , C _trough , CL, t _1/2 , volume of distribution and accumulation factor will be derived from serum drug concentration versus time profiles where relevant and applicable, (e) immune response from immunogenicity assay results, and (f ) levels of immune cell infiltrate and other exploratory biomarkers in tumor biopsies before and during treatment. The study may also evaluate: (a) one-year OS, defined as the proportion of patients who receive at least one dose of anti-FGFR2-IIIb antibody and are alive one year later, (b) DOR, limited to patients with investigator-defined response according to RECIST v1. 1 and defined as the time of first response as defined by the investigator according to RECIST v1.1 to progression or death, whichever comes first, (c) correlation between determined FGFR2 status in biopsy analysis based on tumor tissue and/or blood ( ctDNA) and objective response according to RECIST v1.1, (d) correlation between determined FGFR2 status in tumor tissue and FGFR2 amplification in a blood-based biopsy (ctDNA) assay, (e) blood-based search biomarkers, and (f) change from baseline level in quality of life as measured by EQ-5D-5L and EORTC QLQ-C30.

[00166] The study design is as follows. The study is a two-part, multicenter study to evaluate the safety, tolerability, PK, PD, and efficacy of an anti-FGFR2-IIIb antibody when administered in combination with mFOLFOX6. The study will include an open dose escalation study in Part 1 and a randomized, double-blind, placebo-controlled study in Part 2 in patients with FGFR2b+ gastric cancer. Part 1 consists of at least 2 scheduled dosing cohorts of anti-FGFR2-IIIb antibody in combination with mFOLFOX6 in eligible patients with advanced GI tumors to determine the RD of anti-FGFR2-IIIb antibody to be administered in combination with mFOLFOX6. Part 2 consists of two extension groups (1:1 randomization) to evaluate the safety and efficacy of anti-FGFR2-IIIb antibody in RD in combination with mFOLFOX6 versus placebo and mFOLFOX6 in patients with FGFR2b-selective advanced gastric cancer (determined by prospective immunohistochemical (IHC) analysis of FGFR2b expression and/or a blood test demonstrating FGFR2 amplification). Patients will be included in part 1 or part 2 of the study, but not both. After an initial screening period of up to 14 days (2 weeks), patients will receive mFOLFOX6 treatment (with or without anti-FGFR2-IIIb antibody) every 2 weeks in 14-day cycles. Patients may have started or received mFOLFOX6 chemotherapy prior to inclusion in Part 1, but the eligibility criteria require the patient to be a candidate for at least 2 additional cycles of mFOLFOX6 chemotherapy (there is no upper limit on the number of cycles of FOLFOX6 treatment in Part 1). 1, which patients may or may not have received). Each patient included in Part 1 will be followed up for 28 days to assess safety and the occurrence of dose-limiting toxicity (ESW period). At the end of the EBRT period, patients may continue to receive anti-FGFR2-IIIb antibody in combination with mFOLFOX6 at the discretion of the investigator. Additional treatments may be given every 2 weeks in 14-day cycles until radiographic or clinical evidence of disease progression as assessed by the investigator, unacceptable toxicity occurs, or until the patient meets any of the other exclusion criteria specified in the protocol. There is no maximum dose of anti-FGFR2-IIIb antibody. Continued use of the mFOLFOX6 regimen after the EBRT period will be conducted in accordance with the regional standard of care. In Part 2, patients with tumor positive for FGFR2b on IHC (2+ or 3+) or blood tests completed 2 cycles of mFOLFOX6 chemotherapy as standard first-line therapy for advanced gastric cancer and signed informed consent , will be randomized in a 1:1 ratio to treatment with anti-FGFR2-IIIb antibody in combination with mFOLFOX6 or placebo and mFOLFOX6 every 2 weeks in 14-day cycles in the RD selected after evaluating the data obtained in Part 1. Enrolled patients can continue treatment every 2 weeks in 14-day cycles until radiographic or clinical evidence of disease progression as judged by the investigator, unacceptable toxicity occurs, or until the patient meets any of the other exclusion criteria specified in the protocol. All treatment decisions will be made by the investigator using local estimates. Upon discontinuation of investigational treatment for reasons other than progression or withdrawal of consent, tumor evaluations will continue until the patient is started on additional cancer therapy. In addition, patients in both Part 1 and Part 2 will undergo an extended follow-up period for survival through clinic or telephone visits approximately every 3 months ± 28 days after the EOT visit, up to 24 months after the last patient is included. into the study, or until death, loss to follow-up, withdrawal of consent, or termination of the study by the sponsor (whichever comes first).

[00167] Part 1 is an open dose escalation study of anti-FGFR2-IIIb antibody in combination with mFOLFOX6. Eligible patients in Part 1 have non-selective gastrointestinal cancer (with or without tumors overexpressing FGFR2b) with unresectable, locally advanced, or metastatic disease and are candidates for both FGFR2-IIIb antibodies and mFOLFOX6 chemotherapy. FGFR2 status will be determined retrospectively using IHC and blood-based biopsy (cDNA) analysis. Patients included in Part 1 will be treated with escalating doses of anti-FGFR2-IIIb antibodies in combination with the mFOLFOX6 fixed-dose core chemotherapy regimen every 2 weeks for 14-day cycles as follows:

[00168] Administration of Anti-FGFR2-IIIb Antibodies: Anti-FGFR2-IIIb is administered intravenously every 2 weeks on Day 1 of each cycle prior to the administration of mFOLFOX6 chemotherapy. Anti-FGFR2-IIIb antibodies will be administered as an intravenous infusion over approximately 30 minutes via a peripheral vein or central venous catheter with an inline filter.

[00169] Primary chemotherapy regimen: Administration of mFOLFOX6 chemotherapy begins on day 1 of each treatment cycle and after administration of anti-FGFR2-IIIb antibodies (after a 30-minute rest). The mFOLFOX6 regimen is administered every 2 weeks as follows: IV infusion of oxaliplatin 85 mg/m ² over 120 minutes, IV infusion of leucovorin 400 mg/m ² over 120 minutes, followed by an IV bolus of fluorouracil (5 FU) 400 mg/m ² followed by the introduction of 5-FU 2400 mg/m ² as a continuous intravenous infusion for 46 hours. With the introduction of oxaliplatin, preliminary hydration is not required. Premedication with antiemetics such as serotonin antagonists with or without dexamethasone may be used when clinically indicated at the discretion of the investigator according to local standard of care. Dose Levels (Part 1) Part 1 provides for two anti-FGFR2-IIIb dosing cohorts using a standard 3+3 dose escalation schedule with a minimum of 3 patients per cohort. Expected dose levels: Dose level 1: 10 mg/kg anti-FGFR2-IIIb antibody, Dose level 2: 15 mg/kg anti-FGFR2-IIIb antibody, Dose level -1 : 6 mg/kg anti-FGFR2-IIIb antibody (only if required dose reduction from dose level 1).

[00170] All dose escalation decisions will be based on an assessment of EBRT, overall safety and tolerability, and will be made after the last patient included in each cohort completes the 28-day period of EBRT (completion of 2 treatment cycles). Dose escalation decisions will be approved by the Cohort Review Committee (CRC), which includes the sponsor and investigators. Analysis of safety and PK parameters can help guide decisions about adding cohorts at alternative dose levels to achieve the optimal target exposure. Recruitment to dose level -1 will only be performed if ≥ 2 EBRTs are observed at dose level 1. DLTs are defined below.

[00171] Decisions to increase the dose will be based on the following algorithm: if none of the 3 patients in the cohort has EBRT, the next cohort can be opened; if 1/3 of patients in a cohort have ESWL, include 3 more patients in the same cohort; if 2/3 or 3/3 of the patients in the cohort have ESWL, stop recruitment and enter 3 more patients in the lower cohort (i.e. lower dose level) if the previous cohort had only 3 if 1/6 of patients in a cohort with ESWL, open the next cohort and if 2/6 or more patients have ESWL, discontinue recruitment and add 3 more patients to the cohort at the lower dose level if only 3 patients were included in this cohort.

[00172] The RD for anti-FGFR2-IIIb antibodies for Part 2 will be determined by CRC based on overall safety, tolerability, and PK. Therefore, the RD may or may not coincide with the determined maximum tolerated dose (MTD). For example, if the MTD is not achieved, or if data from subsequent treatment cycles in Part 1 provide additional insight into the safety profile, then the RD may be different from, but not higher than, the MTD. The MTD is defined as the maximum dose at which <33% of patients experience SWL during the SWL period. If ESWL occurs in 1 out of 3 patients at a given dose level, then 3 more patients will be included at the same dose level. Dose escalation may continue until 2 out of 3-6 patients treated at the dose level experience DLT (dose level should not exceed 15 mg/kg). Then the next lower dose will be considered the MTD. Upon reaching the MTD or RD, up to 6 additional patients will be added to further study safety and PK at this dose level. Thus, the total set for Part 1 will be approximately 9 to 12 patients. Any patient who does not receive 2 doses of anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 during the ESW period will be considered non-evaluable and the patient will be replaced. The replaced patient may continue to participate in the study after discussion with the sponsor. No more than 2 doses of anti-FGFR2-IIIb antibodies or 2 cycles of mFOLFOX6 should be administered during a 28-day period of ESWL. At the end of the EBRT period, patients may continue to receive anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 administered every 2 weeks in 14-day cycles until radiographic or clinical evidence of disease progression as judged by the investigator, unacceptable toxicity occurs, or until the patient meets any of the other conditions listed in exclusion criteria protocol. Dose modification criteria for anti-FGFR2-IIIb and mFOLFOX6 antibodies are described below. If mFOLFOX6 chemotherapy is discontinued for any reason prior to disease progression (eg, cumulative toxicity or completion of mFOLFOX6 chemotherapy according to regional practice), anti-FGFR2-IIIb antibodies may be continued as monotherapy and given every 2 weeks until radiological or clinical evidence of disease progression as assessed by the investigator, the occurrence of unacceptable toxicity, or until the patient meets any of the other exclusion criteria specified in the protocol. In the event that an mFOLFOX6 cycle is delayed for more than 14 days due to chemotherapy-related toxicity, administration of anti-FGFR2-IIIb antibodies should not be delayed and may be continued every 2 weeks. Starting a new mFOLFOX6 cycle after dosing deferral should be synchronized with anti-FGFR2-IIIb antibody infusion if possible (but not a study requirement).

[00173] If anti-FGFR2-IIIb antibody is discontinued for any reason prior to disease progression (e.g., cumulative toxicity), mFOLFOX6 chemotherapy may continue to be administered according to local regional practice or until radiographic or clinical confirmation of disease progression as assessed by the investigator, the occurrence of unacceptable toxicity, or until the patient meets any of the other exclusion criteria specified in the protocol.

[00174] Patients will be included in Part 2 to characterize the safety and efficacy of an anti-FGFR2-IIIb antibody in combination with mFOLFOX6 versus placebo and mFOLFOX6 in a patient population with FGFR2b-selective gastric cancer. Recruitment to Part 2 will only begin once a CRC has been determined in Part 1 of the RD for an anti-FGFR2-IIIb antibody that will not exceed 15 mg/kg. Part 2 is double-blind and will consist of a total of approximately 360 patients with FGFR2b-selective gastric cancer randomized 1:1 to receive treatment in one of two groups: group 1: anti-FGFR2-IIIb antibodies in RD and mFOLFOX6 with every 2 weeks, or group 2: placebo and mFOLFOX6 every 2 weeks. The opening of part 2 for recruitment will be at the discretion of the sponsor. Patients with gastric cancer with unresectable, locally advanced, or metastatic disease who are eligible for first-line mFOLFOX6 chemotherapy and have received 2 cycles of mFOLFOX6 will be included in Part 2 of the study. Patients will be selected for inclusion based on FGFR2b overexpression and/or FGFR2 amplification, as determined by a validated IHC or blood-based biopsy (cDNA) assay, respectively. Patients who do not demonstrate FGFR2b overexpression on IHC or amplification on blood-based biopsy (cDNA) analysis will not be eligible for inclusion; however, a positive result on one or both of the assays is sufficient to meet the eligibility requirements (eg, positive on a blood-based [cDNA] biopsy but negative on IHC). Eligible patients may continue treatment every 2 weeks in 14-day cycles until radiographic or clinical evidence of disease progression as judged by the investigator, unacceptable toxicity occurs, or until the patient meets any of the other exclusion criteria specified in the protocol. All treatment decisions will be made by the investigator using local estimates.

[00175] The inclusion criteria are as follows. Patients enrolled in either Part 1 or Part 2 of the study must be over 18 years of age; have inoperable, locally advanced, or metastatic disease; Eastern Cooperative Oncology Group (ECOG) general condition score from 0 to 1; must provide tumor tissue for FGFR2 status determination; provide informed consent; and meet all other eligibility criteria described below. Patients enrolled in Part 1 (introductory dose escalation safety phase) of the study must also meet the following inclusion criteria: Histologically or cytologically confirmed gastrointestinal malignancy for which the mFOLFOX6 regimen is considered an appropriate treatment (eg, gastric, colorectal, cancer, adenocarcinoma of the pancreas). No more than 2 previous chemotherapy regimens for the treatment of metastatic disease (not including previous adjuvant chemotherapy with 5-FU and/or oxaliplatin). The patient must be a candidate for at least 2 cycles of mFOLFOX6 chemotherapy.

[00176] Patients enrolled in Part 2 (maximum tolerated dose extension phase) of the study must also meet the following inclusion criteria: Histologically confirmed adenocarcinoma of the stomach or gastroesophageal junction. FGFR2b overexpression as determined by IHC and/or FGFR2 amplification as determined by a blood biopsy-based assay (cDNA). Prior chemotherapy for the treatment of metastatic or unresectable disease (except as noted in inclusion criteria #20 for the mFOLFOX6 regimen) was not administered. Platinum-based pre-chemotherapy (except as noted in Inclusion Criteria #20 for the mFOLFOX6 regimen) was not administered. If prior adjuvant or neoadjuvant therapy (chemotherapy and/or chemoradiotherapy) has been performed, more than 6 months must elapse between the end of adjuvant therapy and recruitment.

[00177] The patient must be a candidate for mFOLFOX6 chemotherapy and have completed 2 cycles of mFOLFOX6 chemotherapy prior to study entry (but not to exceed 2 cycles). Patients enrolled in Part 1 or Part 2 will be excluded if they have untreated or symptomatic central nervous system (CNS) metastases; cardiac dysfunction or clinically significant heart disease; increased QTcF interval; peripheral sensory neuropathy grade 2 or higher according to the Common Terminology Criteria for Adverse Events (CTCAE) positive status for HER2; or other condition that may increase the risk associated with participation in the study. No waiver of these inclusion or exclusion criteria will be granted.

[00178] In Part 1, anti-FGFR2-IIIb antibodies will be supplied in a sterile reconstitution vial in an IV bag at the study site for approximately 30 minutes every 14 days (+/- 3 days) until radiographic or clinical confirmation of disease progression as assessed by the investigator, unacceptable toxicity, or other reason for exclusion from the study specified in the protocol.

[00179] In Part 2, the masked PI (anti-FGFR2-IIIb/placebo) will be supplied and administered similarly to the unmasked anti-FGFR2-IIIb in Part 1.

[00180] Oxaliplatin, 5-FU, and leucovorin will be supplied to each study center in accordance with institutional practice. The mFOLFOX6 regimen will be administered every 14 days (± 3 days) until radiological or clinical confirmation of disease progression as assessed by the investigator, unacceptable toxicity, or other reason for exclusion from the study as specified in the protocol. For preparation information and full prescription information, see the most recent regional package leaflet.

[00181] Blood samples will be collected to assess the PK parameters of the FGFR2-IIIb antibody, such as AUC, C _max , C _trough , CL, t _1/2 , volume of distribution and accumulation factor. In Part 1, blood samples will be collected at the time points described below to measure serum levels of anti-FGFR2-IIIb antibodies in all registered patients. The second part will collect blood samples from the first 60 patients randomized to part 2 at the time points indicated below. For Part 1 and Part 2, blood samples for determination of anti-FGFR2-IIIb antibody levels will be collected at the indicated time points.

[00182] Evaluation of tumor response will be performed both by the investigator and by blinded central radiological examination in accordance with RECIST v.1.1 guidelines. Full details of the BIRC peer review will be specified in the Imaging Review Charter.

[00183] Efficiency measures will include tumor assessments consisting of clinical examination and studies with appropriate imaging methods, preferably computed tomography (CT) of the chest, abdomen and pelvis with appropriate slice thickness in accordance with RECIST recommendations; other evaluations (magnetic resonance imaging [MRI], radiography, positron emission tomography [PET], and ultrasound) may be done if needed. Tumor assessments will be performed at screening (within 2 weeks post cycle 1, day 1 in part 1 and part 2), then every 6 weeks after the first dose, for 24 weeks, and then approximately every 12 weeks thereafter. After an initial complete response (CR) or partial response (PR) is noted, a confirmatory scan should be performed 4-6 weeks later.

[00184] Safety measures will include AEs, hematology, biochemistry, urinalysis, vital signs, body weight, use of concomitant medications/procedures, ECOG general health score, targeted physical examinations, ECG, and ophthalmic examinations. An independent Data Monitoring Committee (DMC) will regularly evaluate study data for safety (AEs and SAEs) throughout the treatment phase in Part 2.

[00185] In Part 1: Tumor tissue submitted for FGFR2 status assessment will be retrospectively analyzed for FGFR2b overexpression using IHC. Samples for blood-based biopsy analysis (coDNA) will be collected prior to the first dose of study drug (cycle 1 day 1) and analyzed retrospectively for FGFR2 amplification. Blood samples for analysis of exploratory biomarkers will be collected pre-dose on Day 1 of Cycles 1 and 2, 48 hours post-dose of Cycle 1 Day 1 and Cycle 2 Day 1 (Day 3), pre-dose on Cycle 3 Day 1 for patients who continue treatment after the 28-day period of ESWL and during the EOT visit. Hair follicle samples will be collected prior to dosing on Cycle 1, Day 1, Cycle 3, Day 1, and Cycle 5, Day 1, and at the EOT visit for all eligible patients.

[00186] In Part 2: Tumor tissue will be submitted for FGFR2 status assessment and will be prospectively analyzed for FGFR2b overexpression using IHC. Blood samples for ctDNA evaluation will be analyzed prospectively for FGFR2 amplification. In addition, blood-based biopsy (coDNA) assays will be collected longitudinally every 6 weeks from the first dose for 24 weeks and then approximately every 12 weeks thereafter and analyzed retrospectively for FGFR2 amplification. A sample will also be collected at the EOT visit for all Part 2 patients. A sample will also be collected at the EOT visit for all Part 2 patients. Blood samples for analysis of exploratory biomarkers will be collected pre-dose on day 1 of cycles 1 and 2, 48 hours later after dosing in Cycle 1, Day 1 and Cycle 2, Day 1 (Day 3), before dosing in Cycle 3, Day 1, and at the EOT visit.

[00187] Fresh tumor biopsies, mandatory as far as practicable, will be performed before and during treatment within 7 days prior to Cycle 3, Day 1 (and at least 24 hours prior to dosing) in approximately 30 patients randomized to Part 2. Feasibility at each point in time will be assessed by the investigator and should include consideration of patient safety. If the investigator considers that a biopsy cannot be performed, then this determination should be recorded in the source documents. For patients who were biopsied 12 weeks prior to enrollment, this sample may qualify for a new pre-treatment biopsy provided an adequate sample for PD analysis (one paraffin block or approximately 10 slides) is available. Patients in Part 2 may also have an additional during-treatment biopsy for documented tumor response and/or an additional post-treatment biopsy for documented tumor progression after discussion with the sponsor.

[00188] The total number of participants scheduled for this study is approximately 372 patients. Part 1 will include up to 12 patients evaluated for any dose-limiting toxicity according to a standard 3+3 schedule. In Part 2, efficacy and tolerability will be studied by enrolling approximately 360 patients with FGFR2b-selective gastric cancer randomized 1:1 to receive anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 or placebo and mFOLFOX6. Eligible patients will be stratified according to geographic region (US and EU, Asia, Rest of the World), previous treatment status (de novo or adjuvant/neoadjuvant), and measurable disease status (measurable or non-measurable).

[00189] In Part 1, all analyzes will be descriptive and will be presented by dose groups and generally as needed. Descriptive statistics will include number of observations, mean, standard deviation, median, range, and interquartile breadth for continuous variables, and number and percentage for categorical variables; 95% confidence intervals will be presented where appropriate. In Part 2, the primary efficacy analysis is a comparison of PFS in patients treated with anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 or placebo and mFOLFOX6. The primary endpoint, PFS, is defined as the time from randomization to the date of radiological confirmation of disease progression based on investigator assessment (according to RECIST v.1.1) or death from any cause, whichever comes first. Secondary efficacy endpoints include OS and ORR. There will be an interim analysis and a primary PFS analysis, both based on events. Only an interim PFS test will be performed at an interim analysis after 48 events (50% of the target 96 PFS events for the primary PFS analysis) seen in enrolled patients to rule out HR>0.806 for the combination of anti-FGFR2-IIIb and mFOLFOX6 antibodies versus placebo and mFOLFOX6 . It is estimated that an interim analysis will be conducted approximately 20 months after enrollment of the 1st patient. Primary PFS analysis will be conducted after at least 96 PFS events have been reported in the first 156 registered patients, and will be performed using an intent-to-treat (ITT) patient population. The primary analysis will include only cases of radiologically confirmed progression as determined by the investigator according to RECIST v.1.1, and deaths. Primary analysis of PFS will be performed using a stratified log-rank two-tailed test with a significance level of 0.05. The stratification factors will be the same as for randomization schedule stratification as described in the Interactive System Allowing Phone Call and Internet Access (IXRS). If the p-value for the stratified log-rank test is statistically significant (<0.05, two-tailed) and HR<1, the null hypothesis of no difference in PFS will be rejected and it will be concluded that PFS is statistically prolonged in the treated group. antibodies to FGFR2-IIIb in combination with mFOLFOX6, compared with the placebo and mFOLFOX6 group. The median PFS and the corresponding 95% confidence interval for each treatment group will be estimated using the Kaplan-Meier method. The hazard ratio (HR=λ _{anti-FGFR2-IIIb+mFOLFOX6} /λ _mFOLFOX6 ) will be estimated using a Cox regression model with treatment group as the single main effect and stratification using the same stratification factors as used for the log-rank test. Unstratified HR will also be presented.

[00190] Analysis of secondary endpoints, including OS and ORR, will be performed if the primary endpoint, PFS, is statistically significant, and the formal hypotheses of OS and ORR will be tested hierarchically at the 0.05 level. OS will be checked first and if it is significant then ORR will be checked. The Type I error rate for primary and secondary endpoint testing will be controlled by this fixed sequence testing procedure at the 0.05 level. Interim and final OS analyzes are planned if the test for PFS is statistically significant. An interim OS analysis will be performed during the initial PFS analysis. In the case of an OS analysis, an OS analysis in the interim (ie, when at least 96 PFS events have been observed) and at the end (ie, when 249 deaths have been observed) will be performed in the ITT population. OS hypothesis testing will be performed using a stratified log-rank two-tailed test with a significance level of 0.05. The group sequential method will be used to allocate type I error rates based on O'Brien-Fleming cut-off criteria and type II error rates based on a family of gamma distributions with parameter -4 in the intermediate and final OS analysis. The stratification factors will be the same as for randomization schedule stratification as described in IXRS. Median OS and corresponding 95% confidence interval for each treatment group will be estimated using the Kaplan-Meier method. HR will be estimated using a Cox regression model with treatment group as the single main effect and stratification using the same stratification factors used for the log-rank test. Unstratified HR will also be presented. ORR is defined as the proportion of patients with a partial or complete response as determined by the investigator according to RECIST v.1.1. Primary ORR analysis will be performed among patients with measurable disease at baseline. In the analysis of ORR, patients who do not have adequate post-baseline tumor scores will be counted as non-responders. A formal test of the ORR hypothesis will be carried out using the stratified Cochran-Mantel-Haenszel test. The stratification factors will be the same as for randomization schedule stratification as described in IXRS.

[00191] Power and Sample Size: This study is designed to provide adequate power for primary PFS analysis. Based on the median PFS (mPFS) for patients treated with placebo and mFOLFOX6 for 6 months, approximately 156 patients (randomized 1:1) with a target of 96 PFS events should demonstrate a hazard ratio (HR) of 0.5 for mPFS with power 90% (2-tailed α = 0.05) for the combination of anti-FGFR2-IIIb and mFOLFOX6 antibodies compared to placebo and mFOLFOX6 at 24 months post-enrollment and 6 months follow-up. Assuming an exponential distribution of PFS, this corresponds to an increase in mPFS from 6 to 12 months. In the current design, the minimum observed effect that would result in statistical significance for PFS is a 50% improvement (HR=0.67) from 6 to 9 months. This study is also designed for primary analysis of OS. Based on the median OS (mOS) for patients treated with placebo and mFOLFOX6 for 10 months, enrollment in the study will continue to approximately 360 patients with a target of 249 deaths to demonstrate an HR of 0.7 for mOS with a power of 80% at the overall level type I errors of 0.05 for the combination of antibodies to FGFR2-IIIb and mFOLFOX6 compared with placebo and mFOLFOX6 at 36 months after inclusion and 10 months of follow-up after registration of the last patient. Assuming an exponential distribution of OS, this corresponds to a 43% increase in median OS from 10 to 14.3 months. In the current design, the minimum observed effect that would result in statistical significance for OS in the final analysis is a 28% improvement (HR=0.78) from 10 to 12.8 months.

[00192] Safety Analysis: The safety analysis will include all patients who receive any investigational drug (anti-FGFR2-IIIb and mFOLFOX6 antibodies or placebo and mFOLFOX6) during the entire study period and provide any post-treatment safety information. All AEs will be coded using the Medical Regulatory Dictionary (MedDRA). The investigator will classify the severity of the AE using CTCAE v 4.03. An adverse event occurring during treatment (AEEP) is defined as any event with an onset date on or after the date of administration of the first dose of study drug, or any event present before treatment that worsens after treatment. The summary tables will include only NJVL with a date of occurrence before the date of the last dose + 30 days. The number and percentage of patients who experience AEs will be summarized by organ system class, preferred term, causation with study drug, and severity for each treatment group. A patient list will be provided for those patients who experience SAEs, including death, or AEs associated with early withdrawal from the study or discontinuation of study drug. The data of clinical and laboratory analyzes will be summarized by type of laboratory research. The number and percentage of patients who develop abnormalities (i.e., values outside the normal ranges) and/or clinically significant abnormalities following study drug administration will be reported for each clinical laboratory test score. For each clinical laboratory test score, descriptive statistics will be provided for baseline and all subsequent scheduled post-treatment visits. Changes from baseline to post-treatment visits will also be provided. Descriptive statistics on vital signs will also be provided in a similar manner. In addition, by treatment group, shifts from baseline in CTCAE grade (where applicable) and high/low scores (in cases where CTCAE grades are not defined) will be presented. No formal security endpoint comparisons are planned.

[00193] PK analysis: PK parameters will be assessed using non-compartmental analysis, although compartmental analysis may be used if necessary.

Detailed description of the protocol

1. Introduction

Antibodies to FGFR2-IIIb, state of the art

[00194] The role of the fibroblast growth factor receptor (FGFR) pathway in cancer is well known. FGFs can stimulate the transformation and proliferation of tumor cells, as well as stimulate angiogenesis. There are 22 known human FGFs with single FGF expression, usually limited to certain tissues, cell types and/or developmental stage. FGF signaling is mediated by a family of transmembrane tyrosine kinase receptors encoded by four different genes producing FGF receptor subtypes called FGFR1-4 (Turner and Grose 2010).

[00195] FGFR2 has two splicing variants, b and c. In general, FGFR2b is expressed in tissues of epithelial origin (eg stomach, skin) (Miki 1992). The main ligands that signal through FGFR2b are FGF7, FGF10 and FGF22. Alterations in signaling in the FGF/FGFR2 pathway (eg, overexpression of the FGFR2b protein or amplification of the FGFR2 gene) have been associated with gastric, breast, and other cancers and appear to portend a worse prognosis (Wu 2013, Turner and Grose 2010) . In fact, as early as 1990, it was noted that subgroups of patients with gastric cancer (~3-9%) and breast cancer (1 to 2%) had amplification of the FGFR2 gene, which is located on chromosome 10q26. In gastric cancer , FGFR2 amplification leads to a high level of expression of the FGR2b receptor on the cell surface.

FGFR2b-specific antibody

[00196] An anti-FGFR2-IIIb antibody is a humanized monoclonal antibody (IgG1 isotype) specific for the human FGFR2b receptor (NCBI reference sequence identification number NP_001138385.1) that blocks FGF ligand binding to the receptor. The FGFR2-IIIb antibody is directed against the third Ig region of the FGFR2b receptor isoform, a region that is alternatively spliced and regulates ligand specificity. This antibody is glycosylated, but is produced in the Chinese hamster ovary (CHO) cell line, which lacks the FUT8 (α1,6 fucosyltransferase) gene and therefore lacks core fucose in the polysaccharide portion of the antibody. The absence of core fucose results in a higher affinity for the Fc receptor FcγRIIIa compared to the fucosylated molecule and potentially enhances immune cell-mediated killing of tumor cells (Shinkawa 2003). Thus, an antibody was obtained using glycoengineering to enhance antibody-dependent cell-mediated cytotoxicity (ADCC) (Gemo 2014). Anti-FGFR2-IIIb antibody inhibits FGF ligand-stimulated FGFR2b phosphorylation and cell culture proliferation in FGFR2b overexpressing gastric and breast cancer cell lines. The anti-FGFR2-IIIb antibody also inhibits tumor growth in gastric and breast xenograft models overexpressing FGFR2b. Thus, the 3 potential mechanisms of action of an anti-FGFR2-IIIb antibody include blocking ligand binding and downstream signaling, downregulation of the FGFR2b driver protein, and upregulation of ADCC.

[00197] An anti-FGFR2-IIIb antibody can induce complete and long-term inhibition of tumor growth in gastric cancer xenografts with FGFR2b overexpression and FGFR2 gene amplification in immunodeficient mice, where FGFR2b is thought to be a driver of tumor growth (Gemo 2014). In addition, the FGFR2-IIIb antibody demonstrates NK cell recruitment and concomitant tumor growth inhibition in a syngeneic 4T1 tumor model with moderate FGFR2b expression. These data suggest that ADCC may be effective in patients without FGFR2 gene amplification with moderate FGFR2b overexpression, and that ADCC activity may be a major factor in the mechanism of action in these patients.

[00198] Additionally, because the FGFR2-IIIb antibody is specific for the FGFR2b receptor, it does not interfere with signaling of other FGF/FGFRs, including FGFR2c. Unlike FGFR tyrosine kinase inhibitors (TKIs), anti-FGFR2-IIIb does not inhibit FGF23 signaling. FGF23 is a ligand involved in calcium/phosphate metabolism. Thus, treatment with anti-FGFR2-IIIb antibodies is not expected to cause significant dose-limiting hyperphosphatemia associated with FGFR TKIs ( Andre 2013, Brown 2005 , Dienstmann 2014, Sequist 2014 ).

mFOLFOX6

[00199] Infusional 5-fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) is an approved chemotherapeutic agent and standard of care for first-line therapy for metastatic gastric cancer. 5-FU is the main chemotherapeutic agent used to treat gastric cancer worldwide and is often combined with other therapies after studies have shown improved clinical outcomes with 5-FU combination chemotherapy (Keam 2008). The standard drug ^Adrucil® , also known as 5-fluorouracil (5-FU), is a widely used chemotherapeutic agent currently indicated for the treatment of colorectal, breast, gastric, and pancreatic cancers.

Rationale for starting doses of antibodies to FGFR2-IIIb and mFOLFOX6

[00200] An initial dose of 10 mg/kg of anti-FGFR2-IIIb antibodies, administered as an intravenous infusion every 2 weeks in 28-day cycles, is scheduled for Part 1 of this study as part of the run-in phase to assess safety with dose escalation.

[00201] In a previous Phase I clinical study, dose escalation was performed in patients with solid tumors (n=19) and patients with gastric cancer (n=8). During dose escalation, no dose-limiting toxicity (DLT) was observed at any dose level, and therefore no maximum tolerated dose (MTD) of anti-FGFR2-IIIb antibodies was identified. The dose of 15 mg/kg was selected as the extended dose based on preclinical modeling of drug target concentrations and observed tolerability, as well as evidence of observed efficacy. At 15mg/kg every 2 weeks, most patients are expected to achieve the minimum steady state (C _{trough ss} ) FGFR2-IIIb antibody concentration of 60µg/mL, which was derived from a mouse efficacy study using OCUM2 FGFR2 - amplified xenograft model of gastric cancer.

[00202] Based on published data from population PK analyses, there were no clinically significant differences in PK by race for antibody therapeutics, including bevacizumab (Genentech Inc.), trastuzumab (Genentech Inc.), pertuzumab (Genentech Inc. 2016), and ramucirumab (Eli Lilly and Company). It is important to note that clinical data from an ongoing study of antibodies to FGFR2-IIIb confirm that the 10 mg/kg dose is tolerable in humans. The anti-FGFR2-IIIb antibody also showed an acceptable safety profile in a first human study of 53 patients treated at doses up to 15 mg/kg.

[00203] The initial dose of mFOLFOX6 includes 85 mg/m ² oxaliplatin, 350 mg calcium folinate (folinic acid), 400 mg/m ² fluorouracil, and 2400 mg/m ² fluorouracil. Oxaliplatin and calcium folinate are administered simultaneously by intravenous infusion using a 3-way stopcock/Y-piece. A lower dose of fluorouracil is given by intravenous bolus injection, and a larger dose of fluorouracil is given by intravenous infusion over 46 hours. mFOLFOX6 is administered every 14 days.

Rationale for pre-screening in Part 2

[00204] Anti-FGFR2-IIIb is an antibody designed to recognize the FGFR2b receptor when expressed in gastric tumors. The current hypothesis is that the presence of FGFR2b will be an important predictor of response in patients with FGFR2b-selective gastric or gastroesophageal cancer (in Part 2). This is based on preclinical observation that only tumors that overexpress FGFR2b responded to treatment with anti-FGFR2-IIIb antibodies in xenograft studies), as well as early results from an ongoing first human study indicating a higher degree of anti-FGFR2 antibody activity. -IIIb in FGFR2b-positive patients.

[00205] Patients in Part 2 will be selected for inclusion based on FGFR2b overexpression and/or FGFR2 amplification, as determined by a validated IHC (score of 2+ or 3+) or blood-based biopsy analysis, respectively. Patients who do not demonstrate FGFR2b overexpression on IHC or amplification on blood-based biopsy analysis will not be eligible for inclusion; however, a positive result on one or both of the assays is sufficient to satisfy the eligibility requirements (eg, positive on a blood-based biopsy but negative on an IHC).

[00206] Part 2 will involve patients who have not previously received chemotherapy for the treatment of metastatic or inoperable disease; if you have previously received adjuvant or neoadjuvant therapy (chemotherapy and/or chemoradiotherapy), more than 6 months must elapse between the end of adjuvant therapy and registration. These patients will need to have inoperable, locally advanced, or metastatic disease and are therefore expected to start treatment (mFOLFOX6) shortly after diagnosis.

[00207] Because it can take up to several weeks to get IHC results, patients who test negative for blood will experience a delay in starting their chemotherapy treatment pending confirmation of their eligibility by IHC results. For this reason, all patients participating in the study were required to have received 2 cycles of mFOLFOX6 at the time of enrollment. Patients could not receive more than 2 cycles or less than 2 cycles as this could lead to an imbalance in treatment among study participants and could potentially make interpretation of study results difficult. It is expected that IHC results can be obtained within the time required for the first 2 cycles of mFOLFOX6. During this time period, patients are not yet enrolled in the study, so the mFOLFOX6 regimen will be administered according to local practice and adverse events should not be reported as part of the study. Patients must provide informed consent prior to screening for blood tests and IHC. If the IHC results are positive, the patient will complete the second course of mFOLFOX6, enter the screening period, and if all other eligibility criteria are met, including the provision of informed consent, will be included in the study. If the IHC results are negative and the blood-based biopsy was also negative, the patient is not eligible to participate in the study.

Rationale for tumor biopsy and blood tests

[00208] Patients in Part 2 of this trial must have both tissue and blood test results; therefore, a patient is not eligible if they cannot provide both tissue and plasma. Patients who do not demonstrate FGFR2b overexpression on IHC or amplification on blood-based biopsy analysis will not be eligible for inclusion; however, a positive result on one or both of the assays is sufficient to meet the eligibility requirements (eg, positive on a blood-based biopsy but negative on an IHC). A blood test will show the amplification of FGFR2 DNA, while an IHC will show the degree of protein expression. Five Prime has developed an anti-FGFR2b antibody for non-clinical use that has been optimized for FGFR2b sensitivity and specificity by IHC.

[00209] In studies evaluating gastric cancer specimens, FGFR2 amplification was unambiguously associated with significant surface expression of FGFR2b as detected by IHC (Gemo 2014). The antitumor effect of the FGFR2-IIIb antibody observed in preclinical studies was based on FGFR2b overexpression in tumor cell lines. Patients without FGFR2b overexpression are unlikely to benefit greatly from treatment with anti-FGFR2-IIIb and mFOLFOX6 antibodies. The selection of patients with FGFR2b-positive tumors for treatment with anti-FGFR2-IIIb antibodies is supported by data from the ongoing first phase 1 study of anti-FGFR2-IIIb antibodies in humans. Study Goals and Endpoints

Part 1: Primary Goals

[00210] Determine the recommended dose (RD) of anti-FGFR2-IIIb antibody when administered in combination with a fixed dose of infusional 5-fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) in patients with advanced gastrointestinal (GI) tumors.

[00211] To evaluate the safety profile of increasing doses of anti-FGFR2-IIIb antibodies when used in combination with mFOLFOX6 in patients with gastrointestinal tumors.

Part 1: Secondary Goals

[00212] To evaluate the safety and tolerability of long-term exposure to anti-FGFR2-IIIb antibodies when used in combination with mFOLFOX6 in patients with gastrointestinal tumors.

[00213] To characterize the pharmacokinetic (PK) profile of antibodies to FGFR2-IIIb when used in combination with mFOLFOX6 in patients with gastrointestinal tumors.

[00214] Characterize the immunogenicity of antibodies to FGFR2-IIIb.

Part 1: Search Targets

[00215] Characterize the pharmacodynamic (PD) profile of an anti-FGFR2-IIIb antibody when administered in combination with mFOLFOX6 by evaluating exploratory biomarkers in blood and hair follicle samples taken from patients with gastrointestinal tumors.

Part 2: Primary Goals

[00216] To evaluate the clinical benefit of anti-FGFR2-IIIb antibodies when administered in combination with mFOLFOX6 compared with placebo and mFOLFOX6 by a progression-free survival (PFS) analysis in patients with FGFR2b-selective gastric cancer or gastric cancer and gastroesophageal cancer (hereinafter referred to as gastric cancer or gastrointestinal cancer).

Part 2: Secondary Goals

[00217] To assess the clinical benefit of anti-FGFR2-IIIb antibodies when administered in combination with mFOLFOX6 versus placebo and mFOLFOX6, using an analysis of overall survival (OS) in patients with FGFR2b-selective gastrointestinal cancer.

[00218] To evaluate the safety and tolerability of anti-FGFR2-IIIb antibodies when administered in combination with mFOLFOX6 versus placebo and mFOLFOX6 in patients with FGFR2b-selective gastrointestinal cancer.

[00219] To characterize the PK profile of anti-FGFR2-IIIb antibodies when administered in combination with mFOLFOX6 in patients with FGFR2b-selective gastric cancer.

[00220] Characterize the immunogenicity of antibodies to FGFR2-IIIb.

[00221] Characterize the PD profile of anti-FGFR2-IIIb antibodies when administered in combination with mFOLFOX6 versus placebo and mFOLFOX6 by analyzing immune cell infiltrate and other exploratory biomarkers in pre- and post-treatment tumor biopsies.

Part 2: Search Targets

[00222] Evaluate the clinical benefit of anti-FGFR2-IIIb antibodies when administered in combination with mFOLFOX6 versus placebo and mFOLFOX6 by PFS analysis based on a blinded independent review committee (BIRC) progression assessment.

[00223] To evaluate the clinical benefit of anti-FGFR2-IIIb antibodies when administered in combination with mFOLFOX6 versus placebo and mFOLFOX6 by analyzing objective response rates (ORR) in patients with FGFR2b-selective gastrointestinal cancer.

[00224] Evaluate the clinical benefit of anti-FGFR2-IIIb antibodies when administered in combination with mFOLFOX6 versus placebo and mFOLFOX6 by BIRC progression-based ORR analysis.

[00225] To evaluate the clinical benefit of anti-FGFR2-IIIb antibodies when administered in combination with mFOLFOX6 versus placebo and mFOLFOX6, by analyzing one-year OS in patients with FGFR2b-selective gastrointestinal cancer.

[00226] To evaluate the clinical benefit of anti-FGFR2-IIIb antibodies when administered in combination with mFOLFOX6 versus placebo and mFOLFOX6, using a duration of response (DOR) analysis in patients with FGFR2b-selective gastrointestinal cancer.

[00227] To study the relationship between FGFR2 status (in tumor tissue and/or blood-based biopsy) and clinical outcome.

[00228] Examine the correspondence between FGFR2 status in tumor tissue and FGFR2 amplification using blood-based biopsy.

[00229] To characterize the PD profile of anti-FGFR2-IIIb antibodies when administered in combination with mFOLFOX6 versus placebo and mFOLFOX6 by evaluating exploratory biomarkers in blood samples from patients with FGFR2b-selective gastric cancer.

[00230] To assess patient outcome (PRO) and quality of life (QOL) treatment outcomes in patients with FGFR2b-selective gastric cancer treated with anti-FGFR2-IIIb antibody in combination with mFOLFOX6 versus placebo and mFOLFOX6.

Part 1: Primary Study Endpoints

[00231] the incidence of grade 2 or higher adverse events (AEs) assessed by the investigator as related to anti-FGFR2-IIIb antibody and clinical laboratory abnormalities defined as dose-limiting toxicity (DLT).

Part 1: Secondary Endpoints

[00232] The frequency of occurrence of AEs, abnormal clinical laboratory results, corneal and retinal examination results, and electrocardiogram (ECG) abnormalities.

[00233] PK parameters of an anti-FGFR2-IIIb antibody, such as area under the serum drug concentration versus time curve (AUC), maximum serum concentration (Cmax), minimum serum concentration (Ctrough), clearance (CL), terminal half-life (t1/2), volume of distribution and accumulation factor will be derived from serum drug concentration versus time profiles, where relevant and applicable.

[00234] Assess the immune response from the immunogenicity assay.

Part 1: Search Endpoints

[00235] Search biomarkers in blood and hair follicle samples.

Part 2: Primary Endpoints

[00236] PFS, defined as the time from randomization to the date of radiological confirmation of disease progression based on investigator assessment (according to RECIST v.1.1) or death from any cause, whichever comes first.

Part 2: Secondary Endpoints

[00237] OS, defined as the time from date of randomization to death from any cause.

[00238] Objective response rate (ORR) based on the investigator's assessment of tumor lesions according to RECIST v1.1.

[00239] The incidence of AEs, abnormalities in the results of clinical and laboratory tests, the results of the study of the cornea and retina, as well as abnormalities on the electrocardiogram (ECG).

[00240] PK parameters of an anti-FGFR2-IIIb antibody in RD when administered in combination with mFOLFOX6, such as AUC, Cmax, Ctrough, CL, t1/2, volume of distribution, and accumulation factor, will be derived from serum drug concentration versus time profiles when appropriate and applicable.

[00241] Immune response as determined by immunogenicity assay.

[00242] Levels of immune cell infiltrate and other exploratory biomarkers in tumor biopsy specimens before and after treatment.

Part 2: Search Endpoints

[00243] One-year OS, defined as the proportion of patients who receive at least one dose of anti-FGFR2-IIIb antibody and are alive one year later.

[00244] DOR limited to patients with investigator-defined response according to RECIST v1.1 and is defined as the time of first response, as defined by the investigator according to RECIST v1.1, to progression or death, whichever comes first.

[00245] Correlation between detected FGFR2 status in tumor tissue and/or blood-based biopsy and objective response according to RECIST v1.1.

[00246] Correlation between detected FGFR2 status in tumor tissue and FGFR2 amplification in blood-based biopsy.

[00247] Search biomarkers in blood samples.

[00248] Change from baseline in quality of life as measured by EQ-5D-5L and EORTC QLQ-C30.

General design and study plan

Review

[00249] This is a two-part, multicenter study to evaluate the safety, tolerability, PK, PD, and efficacy of an anti-FGFR2-IIIb antibody when administered in combination with mFOLFOX6. The study will include an open-label, dose-escalation safety run-in phase in Part 1 and a randomized, double-blind, placebo-controlled, dose-escalation study in Part 2.

[00250] Part 1 consists of at least 2 scheduled dosing cohorts of anti-FGFR2-IIIb antibody in combination with mFOLFOX6 in eligible patients with advanced GI tumors to determine the RD of anti-FGFR2-IIIb antibody to be administered in combination with mFOLFOX6. Part 2 consists of 2 extension arms (1:1 randomization) to evaluate the safety and efficacy of anti-FGFR2-IIIb antibody in RD in combination with mFOLFOX6 versus placebo and mFOLFOX6 in patients with FGFR2b-selective advanced gastric cancer (determined by prospective IHC assay of FGFR2b expression and/or blood test demonstrating FGFR2 amplification). Patients will be included in part 1 or part 2 of the study, but not both.

[00251] After an initial screening period of up to 14 days (2 weeks), patients will receive mFOLFOX6 treatment (with or without anti-FGFR2-IIIb antibody) every 2 weeks in 14-day cycles. Patients may have started or received mFOLFOX6 chemotherapy prior to inclusion in Part 1, but the eligibility criteria require the patient to be a candidate for at least 2 additional cycles of mFOLFOX6 chemotherapy (there is no upper limit on the number of cycles of FOLFOX6 treatment in Part 1). 1, which patients may or may not have received).

[00252] Each patient included in Part 1 will be observed for 28 days to assess safety and the occurrence of dose-limiting toxicity (the period of ESWL). At the end of the EBRT period, patients may continue to receive treatment at the discretion of the investigator. Additional treatments may be administered every 2 weeks in 14-day cycles thereafter if clinically indicated.

[00253] In Part 2, patients whose tumor is positive for FGFR2b on IHC or blood tests who completed 2 cycles of mFOLFOX chemotherapy as standard first-line therapy for advanced gastric cancer and signed an informed consent will be randomized at a ratio of 1:1 for treatment with anti-FGFR2-IIIb antibody in combination with mFOLFOX6 or placebo in combination with mFOLFOX6 every 2 weeks in 14-day cycles in an RD selected after evaluating the data obtained in Part 1.

Initial screening period

Part 1

[00254] The screening period begins after patients sign the Informed Consent Form (FIS). All patients will undergo screening evaluations within 14 days (2 weeks) prior to administration of the first dose of anti-FGFR2-IIIb antibodies. Any non-study procedure related AEs that occur after signing the informed consent form and prior to administration of the first dose of anti-FGFR2-IIIb antibody will not be collected during this period. Patients may have started or received mFOLFOX6 chemotherapy prior to inclusion in Part 1, but the eligibility criteria require the patient to be a candidate for at least 2 additional cycles of mFOLFOX6 chemotherapy (there is no upper limit on the number of cycles of FOLFOX6 treatment in Part 1). 1, which patients may or may not have received).

Part 2

[00255] Part 2 will enroll patients who are tumor positive for FGFR2b on IHC or blood tests, who have completed 2 cycles of mFOLFOX chemotherapy as standard first-line therapy for advanced gastric cancer, and who have signed an informed consent and met other eligibility criteria.

[00256] Eligibility for Part 2 will be assessed in 2 stages: a pre-screening period that includes only testing for FGFR2b positivity by IHC and blood assays; and a screening period in which all other eligibility criteria are confirmed.

Randomization

Part 1

[00257] Part 1 is an open study. Patients who are determined to be eligible will be consecutively included.

Part 2

[00258] During pre-screening, patients will be tested for FGFR2b positivity. Patients who test positive for one or both methods (IHC and/or blood) will then begin the screening period. (Note: if the blood test is positive, there is no need to wait for the IHC results as the patient is eligible at this point and should start the screening period).

[00259] Eligible patients will be randomized 1:1 to placebo in combination with mFOLFOX6 or anti-FGFR2-IIIb in combination with mFOLFOX6.

Part 1 (introductory phase for safety assessment with dose escalation)

[00260] Part 1 is an open dose escalation study of anti-FGFR2-IIIb antibody when administered in combination with mFOLFOX6. Eligible patients in Part 1 have non-selective gastrointestinal cancer (with or without tumors overexpressing FGFR2b) with unresectable, locally advanced, or metastatic disease and are candidates for both FGFR2-IIIb antibodies and mFOLFOX6 chemotherapy. FGFR2 status will be determined retrospectively using IHC and blood-based biopsy.

[00261] Patients included in Part 1 will be treated with escalating doses of anti-FGFR2-IIIb antibodies in combination with an mFOLFOX6 fixed-dose core chemotherapy regimen every 2 weeks for 14-day cycles as follows:

Introduction of antibodies to FGFR2-IIIb:

[00262] Anti-FGFR2-IIIb antibodies are administered intravenously every 2 weeks on day 1 of each cycle prior to the introduction of mFOLFOX6 chemotherapy. Anti-FGFR2-IIIb antibodies will be administered as an intravenous infusion over approximately 30 minutes via a peripheral vein or central venous catheter with an inline filter.

Primary chemotherapy regimen:

[00263] The administration of mFOLFOX6 chemotherapy begins on day 1 of each treatment cycle and after administration of anti-FGFR2-IIIb antibodies (after a 30-minute rest). The mFOLFOX6 regimen is administered every 2 weeks as follows:

[00264] IV infusion of oxaliplatin 85 mg/m ² over 120 minutes, IV infusion of leucovorin 400 mg/m ² over 120 minutes followed by an IV bolus of fluorouracil (5-FU) 400 mg/m ² followed by the introduction of 5-FU 2400 mg/m ² as a continuous intravenous infusion for 46 hours.

[00265] With the introduction of oxaliplatin, pre-hydration is not required. Premedication with antiemetics such as serotonin antagonists with or without dexamethasone may be used when clinically indicated at the discretion of the investigator according to local standard of care.

Dose levels (part 1)

[00266] Part 1 provides for two anti-FGFR2-IIIb antibody dosing cohorts in a standard 3+3 dose escalation schedule, with a minimum of 3 patients per cohort. Expected dose levels:

Dose level 1 10 mg/kg anti-FGFR2-IIIb antibodies Dose level 2 15 mg/kg anti-FGFR2-IIIb antibodies Dose level -1 6 mg/kg anti-FGFR2-IIIb antibodies
(only if dose reduction from baseline dose level 1 is required).

[00267] All dose escalation decisions will be based on an assessment of EBRT, overall safety and tolerability, and will be made after the last patient included in each cohort completes the 28 day period of EBRT (completion of 2 treatment cycles). Dose escalation decisions will be approved by the Cohort Review Committee (CRC), which includes the sponsor and investigators. Analysis of safety and PK parameters can help guide decisions about adding cohorts at alternative dose levels to achieve the optimal target exposure. Recruitment to dose level -1 will only be performed if ≥ 2 EBRTs are observed at dose level 1.

[00268] The algorithm shown in Table 1 will be used to decide whether to increase the dose in Part 1:

Table 1. Dose escalation

Number of patients with EBRT Action 0/3 Open next cohort 1/3 Enroll 3 more patients in the same cohort ≥2/3 Stop dialing. Administer 3 more patients at a lower dose level if only 3 patients were previously administered 1/6 Open next cohort ≥2/6 Stop dialing. Administer 3 more patients at a lower dose level if only 3 patients were previously administered to demonstrate that ≤1 in 6 patients experience ESWL

[00269] The RD for anti-FGFR2-IIIb antibodies for Part 2 will be determined by CRC based on overall safety, tolerability and PK. Therefore, the RD may or may not coincide with the determined maximum tolerated dose (MTD). For example, if the MTD is not achieved, or if data from subsequent treatment cycles in Part 1 provide additional insight into the safety profile, then the RD may be different from, but not higher than, the MTD.

[00270] MTD is defined as the maximum dose at which <33% of patients experience SWL during the SWL period. If ESWL occurs in 1 out of 3 patients at a given dose level, then 3 more patients will be included at the same dose level. Dose escalation may continue until 2 out of 3-6 patients treated at the dose level experience DLT (dose level should not exceed 15 mg/kg). Then the next lower dose will be considered the MTD.

[00271] After reaching the MTD or RD, 3 additional patients will be added to further study the safety and PK at this dose level. Thus, the total set for Part 1 will be approximately 9 to 12 patients.

[00272] Any patient who does not receive exactly 2 doses of anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 during the EBRT period will be considered non-evaluable and the patient will be replaced. The replaced patient may continue to participate in the study after discussion with the sponsor. No more than 2 doses of anti-FGFR2-IIIb antibodies or 2 cycles of mFOLFOX6 should be administered during a 28-day period of ESWL.

[00273] At the end of the EBRT period, patients may continue to receive anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 administered every 2 weeks in 14-day cycles until radiological or clinical confirmation of disease progression as assessed by the investigator, the occurrence of unacceptable toxicity, or until the patient meets any of the other exclusion criteria specified in the protocol. There is no maximum dose of anti-FGFR2-IIIb antibody. Continued use of the mFOLFOX6 regimen after the EBRT period will be conducted in accordance with the regional standard of care.

[00274] If mFOLFOX6 chemotherapy is discontinued for any reason prior to disease progression (e.g., cumulative toxicity or completion of mFOLFOX6 chemotherapy according to regional practice), anti-FGFR2-IIIb antibodies may be continued as monotherapy and administered every 2 weeks prior to radiographic or clinical confirmation of investigator-assessed disease progression, the onset of unacceptable toxicity, or until the patient meets any of the other exclusion criteria specified in the protocol. In the event that an mFOLFOX6 cycle is delayed for more than 14 days due to chemotherapy-related toxicity, administration of anti-FGFR2-IIIb antibodies should not be delayed and may be continued every 2 weeks. Starting a new mFOLFOX6 cycle after dosing deferral should be synchronized with anti-FGFR2-IIIb antibody infusion if possible (but not a study requirement).

[00275] If anti-FGFR2-IIIb antibody is discontinued for any reason prior to disease progression (e.g., cumulative toxicity), mFOLFOX6 chemotherapy may continue to be administered according to local regional practice or until radiological or clinical evidence of disease progression is assessed by the investigator, the occurrence of unacceptable toxicity, or until the patient meets any of the other exclusion criteria specified in the protocol.

Part 2: Randomized double-blind dose escalation

[00276] Patients will be included in Part 2 to characterize the safety and efficacy of an anti-FGFR2-IIIb antibody in combination with mFOLFOX6 versus placebo and mFOLFOX6 in a patient population with FGFR2b-selective gastric cancer. Recruitment to Part 2 will only begin once a CRC has been determined in Part 1 of the RD for an anti-FGFR2-IIIb antibody that will not exceed 15 mg/kg.

[00277] Part 2 is double-blind and will consist of a total of approximately 360 patients with FGFR2b-selective gastric cancer, randomized in a 1:1 ratio to receive treatment in one of two groups:

[00278] Group 1 : anti-FGFR2-IIIb antibodies in RD and mFOLFOX6 every 2 weeks, or

[00279] Group 2: Placebo and mFOLFOX6 administered every 2 weeks

[00280] The opening of Part 2 to the kit will be at the discretion of the sponsor.

[00281] Gastric cancer patients with unresectable, locally advanced, or metastatic disease who are eligible for first-line mFOLFOX6 chemotherapy and received 2 cycles of mFOLFOX6 will be included in Part 2 of the study. Patients will be selected for inclusion based on FGFR2b overexpression and/or FGFR2 amplification, as determined by validated IHC or blood-based biopsy analysis, respectively.

[00282] Eligible patients may continue treatment every 2 weeks in 14-day cycles until radiological or clinical confirmation of disease progression as assessed by the investigator, the occurrence of unacceptable toxicity, or until the patient meets any of the other exclusion criteria specified in the protocol. All treatment decisions will be made by the investigator using local estimates. Upon discontinuation of investigational treatment for reasons other than progression or withdrawal of consent, tumor evaluations will continue until the patient is started on additional cancer therapy. In addition, patients in both Part 1 and Part 2 will undergo an extended follow-up period for survival through clinic or telephone visits approximately every 3 months ± 28 days after the EOT visit, up to 24 months after the last patient is included. into the study, or until death, loss to follow-up, withdrawal of consent, or termination of the study by the sponsor (whichever comes first).

[00283] If mFOLFOX6 chemotherapy is discontinued for any reason prior to disease progression (e.g., cumulative toxicity or completion of mFOLFOX6 chemotherapy according to regional practice), PI administration may be continued as monotherapy and given every 2 weeks until radiographic or clinical evidence of disease progression as judged by the investigator, the occurrence of unacceptable toxicity, or until the patient meets any of the other exclusion criteria specified in the protocol. In the event that an mFOLFOX6 cycle is delayed by more than 14 days due to chemotherapy-related toxicity, PI administration should not be delayed and may be continued every 2 weeks. Starting a new mFOLFOX6 cycle after a dosing delay should be synchronized with the PI infusion if possible (but not a study requirement).

[00284] If an PI is discontinued for any reason prior to disease progression (e.g., cumulative toxicity), mFOLFOX6 chemotherapy may continue to be administered in accordance with local regional practice or until radiographic or clinical evidence of disease progression as assessed by the investigator, unacceptable toxicity, or until the patient meets any of the other exclusion criteria specified in the protocol.

Study scheme

[00285] The study design is shown in FIG. 1 (part 1) and in Fig. 2 (part 2).

Study Design Rationale

[00286] This is a two-part, multicenter study to evaluate the safety, tolerability, PK, PD, and efficacy of an anti-FGFR2-IIIb antibody when administered in combination with mFOLFOX6. The study will include an open-label, dose-escalation safety run-in phase in Part 1 and a randomized, double-blind, placebo-controlled, dose-escalation study in Part 2.

[00287] Part 1 is an introductory phase study to assess the safety of dose escalation of anti-FGFR2-IIIb antibody when administered in combination with mFOLFOX6. A standard 3+3 design will be used. Patients included in Part 1 will be treated with escalating doses of anti-FGFR2-IIIb antibodies in combination with a mFOLFOX6 fixed-dose primary chemotherapy regimen every 2 weeks for 14-day cycles. Each patient included in Part 1 will be followed up for 28 days to evaluate safety and the occurrence of dose-limiting toxicity (ESW period) and an RD will be selected for Part 2 after evaluation of the data.

[00288] Eligible patients in Part 1 have non-selective gastrointestinal cancer (with or without tumors overexpressing FGFR2b) with unresectable, locally advanced, or metastatic disease and are candidates for both anti-FGFR2-IIIb antibodies and chemotherapy regimen mFOLFOX6. FGFR2 status will be determined retrospectively using IHC and blood-based biopsy.

[00289] In the second part, selected patients will be randomized in a 1:1 ratio to treatment with antibodies to FGFR2-IIIb and mFOLFOX6 or placebo and mFOLFOX6 every 2 weeks in 14-day cycles. Patients in Part 2 must complete exactly 2 cycles of mFOLFOX6 (no more and no less).

[00290] Measurement of PFS, ORR, and OS in patients with FGFR2b-selective gastric cancer in randomized patients may highlight the clinical benefit of anti-FGFR2-IIIb antibodies when used in combination with mFOLFOX6 compared to placebo and mFOLFOX6.

Eligibility and Exclusion Criteria

Planned number of patients and research centers

[00291] In Part 1, 2 anti-FGFR2-IIIb antibody dosing cohorts are expected in a standard 3+3 dose escalation schedule, with a minimum of 3 patients per cohort. Once the MTD or RD is reached, 3 additional patients will be added to further study safety and PK at this dose level. Thus, the total set for Part 1 will be approximately 9 to 12 patients.

[00292] In the second part, approximately 360 patients with FGFR2b-selective gastric cancer will be randomized 1:1 to treatment with anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 or placebo in combination with mFOLFOX6 every 2 weeks in 14-day cycles for the RD selected after evaluating the data obtained in Part 1. The opening of Part 2 for recruitment will be at the discretion of the sponsor.

[00293] The total number of participants scheduled for this study is approximately 372 patients.

[00294] The study will be conducted at 250 research centers around the world.

Inclusion criteria for all cohorts

[00295] Patients enrolled in Part 1 or Part 2 of the study must also meet all of the following inclusion criteria:

1) Unresectable, locally advanced or metastatic disease

2) Understand and sign an Informed Consent Form (FIS) approved by an Institutional Review Board (IRB)/Independent Ethics Committee (IEC) prior to any evaluation conducted for a study

3) Life expectancy of at least 3 months

4) General condition score according to Eastern Cooperative Oncology Group (ECOG) from 0 to 1

5) Age ≥18 years at the time of signing the FIS

6) Negative serum β-human chorionic gonadotropin (β-hCG) pregnancy test ≤72 hours prior to enrollment (women of childbearing potential only)

7) For sexually active patients (women of childbearing potential and men), willingness to use 2 effective methods of contraception, of which 1 must be a barrier method (condom, diaphragm, or cervical cap/vaginal cap) within 6 months after the last dose of antibody to FGFR2-IIIb. Other effective forms of contraception include:

Permanent sterilization (hysterectomy and/or bilateral oophorectomy or bilateral tubal ligation or vasectomy) at least 6 months prior to screening

Women of childbearing potential who are on stable oral contraceptive therapy, or who have had an intrauterine or implantable device for at least 90 days prior to study entry, or who abstain from sexual intercourse as a lifestyle

8) Adequate hematological and biological function, confirmed by the following laboratory parameters:

Bone marrow function

Absolute neutrophil count (ANC)≥1.5 × 10 ⁹ /l

Platelets >100 × 10 ⁹ /l

Hemoglobin ≥9 g/dl

liver function

Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤3× upper limit of normal (ULN); in case of liver metastases, then ≤5 × ULN

Bilirubin ≤1.5 × ULN

Kidney function

Estimated creatinine clearance ≥ 50 ml/min

9) Patients receiving full-dose anticoagulants should be on a stable dose of warfarin and have an international normalized ratio (INR) within the therapeutic range to treat the patient's condition or a stable dose of low molecular weight heparin.

10) Measurable or non-measurable disease

11) Tumor tissue for FGFR2 status determination

Patients enrolled in Part 1 (introductory phase for safety assessment with dose increase) studies must also meet the following inclusion criteria:

[00296] Histologically or cytologically confirmed malignant neoplasm of the gastrointestinal tract, for which the mFOLFOX6 regimen is considered an appropriate treatment (for example, gastric cancer, colorectal cancer, pancreatic adenocarcinoma)

[00297] No more than 2 previous chemotherapy regimens for the treatment of metastatic disease (not including previous adjuvant chemotherapy with 5-FU and/or oxaliplatin).

[00298] The patient must be a candidate for at least 2 cycles of mFOLFOX6 chemotherapy.

Patients enrolled in part 2 (maximum tolerated dose extension phase) studies must also meet the following inclusion criteria:

1) Histologically confirmed adenocarcinoma of the stomach or gastroesophageal junction.

2) FGFR2b overexpression as determined by IHC and/or FGFR2 amplification as determined by blood biopsy

3) No prior chemotherapy for metastatic or inoperable disease (except as noted in inclusion criteria #20 for the mFOLFOX6 regimen)

4) No prior platinum-based chemotherapy (except as noted in inclusion criteria #20 for mFOLFOX6 regimen)

5) If prior adjuvant or neoadjuvant therapy (chemotherapy and/or chemoradiotherapy) was performed, more than 6 months must elapse between the end of adjuvant therapy and recruitment

6) The patient must be a candidate for mFOLFOX6 chemotherapy and have completed 2 cycles of mFOLFOX6 chemotherapy prior to enrollment in the study (but no more than 2 cycles).

Exclusion criteria for all cohorts

[00299] Patients enrolled in Part 1 or Part 2 will be excluded if any of the following criteria apply to them:

[00300] Untreated or symptomatic metastases to the central nervous system (CNS). Patients with asymptomatic CNS metastases are eligible provided they have been clinically stable for at least 4 weeks and do not require intervention such as surgery, radiation, or any corticosteroid therapy to treat symptoms associated with CNS disease.

[00301] Impaired cardiac function or clinically significant cardiac disease, including any of the following:

Unstable angina ≤6 months prior to enrollment

Acute myocardial infarction ≤6 months prior to enrollment

Congestive heart failure, class II-IV, according to the functional classification of the New York Heart Association

Uncontrolled hypertension (defined as >160/90 despite optimal medical management)

Cardiac arrhythmia requiring antiarrhythmic therapy other than beta-blockers or digoxin

Active coronary artery disease

7) QTcF >450 ms for men or >470 ms for women

8) Peripheral sensory neuropathy grade 2 or higher according to the Standard Terminological Criteria for Adverse Events (CTCAE)

9) Active infection requiring systemic treatment or any uncontrolled infection ≤14 days prior to registration

10) Confirmed human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS)-associated disease or history of chronic hepatitis B or C

11) History of interstitial lung disease (eg, pneumonitis or pulmonary fibrosis)

12) Evidence or history of hemorrhagic diathesis or coagulopathy

13) Use of any investigational agent or therapy within ≤28 days prior to registration

14) Radiation therapy ≤28 days prior to enrollment. Patients must recover from all toxic effects associated with radiation therapy. Radiopharmaceuticals (strontium, samarium) should not be used within 8 weeks after registration

15) Pretreatment with any selective inhibitor (e.g. AZD4547, BGJ398, JNJ-42756493, BAY1179470) of the FGF-FGFR pathway

16) Current side effects from prior treatment NCI CTCAE Grade 1 (excluding Alopecia Grade 2)

17) Participation in another therapeutic clinical trial within 28 days of enrollment or during that clinical trial

18) History of corneal defects, corneal ulceration, keratitis, keratoconus, corneal transplantation, or other known corneal abnormalities that, in the opinion of the ophthalmologist, may pose a risk during treatment with anti-FGFR2-IIIb antibodies

19) Positive HER2 status (as defined by positive IHC 3+ assay or IHC 2+ positive FISH). HER2 status based on gastric cancer assessment guideline (HercepTest)

20) Major surgery is not allowed ≤28 days prior to enrollment. Surgery requiring local/epidural anesthesia must be completed at least 72 hours before check-in. In all cases, the patient must be sufficiently recovered and stable before starting treatment.

21) Women who are pregnant or breastfeeding (unless the patient wishes to interrupt breastfeeding during study drug administration and then resume 6 months after study termination); women of childbearing potential should not consider becoming pregnant during the study

22) Presence of any serious or unstable comorbid systemic disorder incompatible with clinical investigation (eg, substance abuse, psychiatric disorder, or uncontrolled intercurrent illness including active infection, arterial thrombosis, and symptomatic pulmonary embolism)

23) The presence of any other condition that may increase the risk associated with participation in the study (for example, dihydropyrimidine deficiency or pleural effusion), or may interfere with the interpretation of study results and, in the opinion of the investigator, make the patient ineligible for inclusion in the study

24) Known allergy or hypersensitivity to components of an anti-FGFR2-IIIb antibody formulation, including polysorbate, or to products containing platinum, fluorouracil, or leucovorin

25) Previous history of malignancy, excluding other malignancy which, in the opinion of the Investigator, would not affect the determination of the effect of study treatment.

No waiver of these inclusion or exclusion criteria will be granted.

Exclusion from the study and replacement of the patient

[00302] The patient should stop using the protocol prescribed therapy if any of the following apply:

Withdrawal of consent at the request of the patient or his legal representative

Progression of the patient's disease as assessed by the investigator.

Any event that poses an unacceptable risk to patient safety

Concomitant disease that will significantly affect the assessment of clinical status

Positive pregnancy test at any time during the study

Upon special request from the sponsor or its authorized representative (for example, if the study is terminated for patient safety reasons).

Identification and registration of patients

[00303] Patients must be able to provide written informed consent and meet all of the inclusion criteria and none of the exclusion criteria. The investigator and the sponsor or its designees will not be able to waive any inclusion or exclusion criteria. All eligibility criteria must be met before a patient can be registered. Patients who are eligible for Part 1 of the study will be included in the first available cohort. A patient may be included in part 1 or part 2 of the study, but not both.

[00304] In Part 2, patients first undergo pre-screening, which requires both blood-based biopsy analysis and tissue analysis. Patients who are positive for FGFR2 can immediately enter the screening period (i.e. patients with positive blood test results do not need to wait for IHC results (see Table 2). Patients in Part 2 should also complete 2, but no more than 2 cycles of mFOLFOX6 .

Table 2: Acceptability based on FGFR2b results

FGFR2a amplification ^_
(using blood-based biopsy [cDNA] assay) ^b FGFR2B overexpression by IHC (using IHC tissue assay) ^a
(Tissue testing for FGFR2b protein) ^c Acceptability Blood (+) Positive Suitable Blood (-) Positive Suitable Blood (+) Negative Suitable Blood (-) Negative Unsuitable

a: Both analyzes will be performed at central laboratories.

b: Requires 2 x 10 ml.

c: IHC: A minimum of 5 slides is required. A score of 2+ or 3+ will be considered positive.

[00305] In both parts 1 and 2, the investigator may repeat qualifying laboratory tests and pre-enrollment vital signs/ECG measurements if the non-qualifying finding is considered an error or if the fresh result can meet the retest acceptance criteria. Hematology and blood chemistry results must be obtained within 72 hours of dosing to confirm eligibility.

Investigational drug

Identity

[00306] In Part 1, anti-FGFR2-IIIb antibodies will be supplied in a sterile reconstitution vial in an IV bag at the study site for approximately 30 minutes every 14 days (± 3 days) until radiographic or clinical confirmation of disease progression as assessed by the investigator, unacceptable toxicity or other reason for exclusion from the study specified in the protocol.

[00307] In Part 2, the placebo will be supplied by an unblinded research center pharmacist. Participants will be randomly assigned in a [1:1] ratio to receive a masked PI (anti-FGFR2-IIIb/placebo). Investigators will remain blinded to each participant's assigned treatment for the duration of the study. In order to maintain blinding, the unblinded pharmacist will be responsible for reconstitution and distribution of all investigational treatment. In the case of a quality assurance audit, the auditor(s) will be allowed access to unmasked study treatment records at the study site(s) to ensure that randomization/allocation has been performed accurately.

[00308] Oxaliplatin, 5-FU, and leucovorin will be supplied to each study center in accordance with institutional practice. The mFOLFOX6 regimen will be administered every 14 days (± 3 days) until radiological or clinical confirmation of disease progression as assessed by the investigator, unacceptable toxicity, or other reason for exclusion from the study as specified in the protocol. For preparation information and full prescription information, see the most recent regional package leaflet.

Introduction

1.mFOLFOX6

[00309] Oxaliplatin, 5-FU, and leucovorin will be supplied to each study center in accordance with institutional practice. The mFOLFOX6 regimen will be administered every 14 days (± 3 days) until disease progression, unacceptable toxicity, or other protocol-restricted reason for withdrawal from the study.

[00310] The initial dose of mFOLFOX6 includes 85 mg/m ² oxaliplatin, 350 mg calcium folinate (folinic acid), 400 mg/m ² fluorouracil, and 2400 mg/m ² fluorouracil. Oxaliplatin and calcium folinate are administered simultaneously by intravenous infusion using a 3-way stopcock/Y-piece. A lower dose of fluorouracil is given by intravenous bolus injection, and a larger dose of fluorouracil is given by intravenous infusion over 46 hours. mFOLFOX6 can be administered every 14 days.

[00311] For preparation information and full prescription information, see the most recent instructions for use.

2. Open introduction of antibodies to FGFR2-IIIb (part 1) and administration of a masked PI (part 2)

[00312] Anti-FGFR2-IIIb antibodies will only be administered to patients in this study using the procedures described in this protocol. The dose of anti-FGFR2-IIIb antibodies is based on body weight on day 1 of cycle 1 and is adjusted if the patient's weight changes by >10% from day 1 of cycle 1.

[00313] The pharmacist (or other responsible person) will prepare the solution for administration. After calculating the number of vials, based on the weight of the patient, the study drug is diluted in 0.9% sodium chloride solution. Prepared anti-FGFR2-IIIb antibodies should be administered ≤8 hours after preparation (at room temperature). Anti-FGFR2-IIIb antibodies will be administered under medical supervision over approximately 30 minutes of intravenous infusion with an inline filter through a peripheral vein or central venous catheter. For part 2, the pharmacist, who will not be blinded to prescribing treatment, will provide a placebo.

[00314] The infusion of antibodies to FGFR2-IIIb should be suspended, reduced, interrupted or stopped earlier. If the patient experiences an infusion reaction, the patient's vital signs (temperature, blood pressure, pulse, and respiratory rate) should be monitored during the infusion and every 30 minutes after the infusion for at least 2 hours until the infusion reaction resolves.

[00315] Patients will receive 2 doses of anti-FGFR2-IIIb antibodies 2 weeks apart during the entire study period. In Part 1, after the end of the EBRT period, if patients tolerate treatment without disease progression, patients may continue to receive anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 administered every 2 weeks in 14-day cycles until radiographic or clinical confirmation of disease progression as assessed by the investigator, the occurrence of unacceptable toxicity, or until the patient meets any of the other exclusion criteria specified in the protocol.

Starting dose and dose modifications

3. Part 1: Introductory phase for assessing safety with dose escalation

[00316] Patients included in Part 1 will be treated with escalating doses of anti-FGFR2-IIIb antibodies in combination with a mFOLFOX6 fixed-dose core chemotherapy regimen every 2 weeks for 14-day cycles as described above.

Dose Modification Criteria

4. Open introduction of antibodies to FGFR2-IIIb (part 1) and administration of a masked PI (part 2)

[00317] Part 1 and Part 2: Dose reduction of anti-FGFR2-IIIb antibodies may be allowed for patients treated after the EBRT period in Part 1, or for any patient in Part 2, as recommended in Table 3. If the investigator is considering dose reductions or interruptions that do not fall under these recommendations and will require discussion and approval by the sponsor or their designee.

Table 3: Dose Modification Recommendations for Anti-FGFR2-IIIb Antibodies

Degree of toxicity Anti-FGFR2-IIIb dose Dose Schedule 1 or 2 Continue to inject 100% of the dose No delay or missed dose required 3 or 4
(first occurrence) Continue administering 100% of initial dose after recovery to baseline or Grade 1 Delaying or skipping a dose 3 or 4 (second occurrence) Continue one dose level lower than previous dose after recovery to baseline or Grade 1 Delaying or skipping a dose 3 or 4 (third occurrence) Permanently stop administration of anti-FGFR2-IIIb antibodies N/A

[00318] Patients may resume study medication if the condition due to the event returns to baseline or grade ≤ 1, as recommended in Table 3.

[00319] There is a ± 3 day window for scheduled dosing visits. Patients should not receive 2 consecutive doses of anti-FGFR2-IIIb antibodies within 7 days. The first dose of each cycle is considered 1 day of each cycle. Cycles will repeat every 14 days unless there is a delay in treatment.

[00320] Increasing the dose for the patient above the initial dose for each patient is not allowed. If the patient's dose is reduced for a reason that is no longer relevant, an increase in dose to the original dose may occur after discussion and approval by the sponsor.

5.mFOLFOX6

[00321] Part 1 and Part 2: Patients should be closely monitored for mFOLFOX6 toxicity. Dose adjustments of 5-FU and oxaliplatin may be allowed for patients on treatment, but patients who require a dose adjustment or deferral of any mFOLFOX component during the period of ESWL will not be considered eligible unless the dose adjustment or deferral is due to an AE associated with an anti-FGFR2-IIIb antibody, in which case the AE would be considered EBRT (see below for the definition of EBRT). Other than the period of ESWL in Part 1 or any patient in Part 2, dose adjustments for any component of mFOLFOX are permitted according to protocol guidelines.

[00322] In the event that oxaliplatin is discontinued for any reason prior to disease progression, 5-FU/leucovorin therapy may be continued every 2 weeks until disease progression, unacceptable toxicity, or other reason to terminate the study.

[00323] Dose adjustments for mFOLFOX6 toxicity are shown in Table 4.

Table 4: Dose Reductions and Delays for FOLFOX Chemotherapy

Toxicity at the beginning of subsequent cycles of therapy Degree Oxaliplatin 5-FU Leukocytes < 3000/mm ³ Suspend until resolved Neutrophils < 1,000/mm ³ platelets < 100,000/ ^mm3 Diarrhea ≥ 1 Mucositis ≥ 1 Any other non-hematological toxicity ≥ 2 Palmar-plantar syndrome 3-4 100% Stop Neurotoxicity ≥ 3 Stop 100%

Previous toxicity (after clearance) Degree Oxaliplatin 5-FU Neutropenia > 5 days 4 75% 100% Febrile neutropenia 4 Thrombocytopenia 3-4 Diarrhea 3 100% 75% Diarrhea 4 100% 50% Stomatitis 3 100% 75% Stomatitis 4 100% 50% Myocardial ischemia --- 100% Stop

Based on protocol materials: Loupakis F, Cremolini C, Masi G, et al. Initial therapy with FOLFOXIRI and bevacizumab for metastatic colorectal cancer. N Engl J Med 2014;371:1609-18. DOI: 10.1056/NEJMoa1403108.

Dose limiting toxicity

[00324] DLT is defined as any of the following events that occur during the first 28 days of treatment and are assessed by the investigator as being related to anti-FGFR2-IIIb antibodies. If applicable, events will be classified according to NCI CTCAE (Version 4.03).

ANC <0.5 × 10 ⁹ /L >5 days or febrile neutropenia (i.e. ANC <1.0 × 10 ⁹ /L with one case of fever >38.3°C or fever ≥38°C during over 1 hour). The use of G-CSF is permitted according to institution standards

Platelets <25 × 10 ⁹ /L or platelets <50 × 10 ⁹ /L with bleeding requiring medical attention

Prolonged thrombocytopenia (>7 days) grade 3

Grade 4 anemia (i.e. life-threatening consequences; urgent intervention indicated)

Any ophthalmic AE grade 2 or higher that does not resolve within 7 days

AST/ALT >3 x ULN and concomitant total bilirubin > 2 x ULN not associated with liver cancer

Any non-hematologic AE of grade 3 or higher (except nausea, vomiting, and diarrhea if well controlled with systemic drugs). Grade 3 or 4 laboratory values that are not clinically relevant as agreed between the investigator and sponsor will not be considered EBRT.

Any adverse event associated with antibodies to FGFR2-IIIb that results in a dose reduction or delay of at least 4 days of any component of mFOLFOX6

Recommended dose (RD) and maximum tolerated dose (MTD)

Toxicity at the lowest dose level

[00325] If the MTD is unexpectedly exceeded at the first dose level of anti-FGFR2-IIIb antibodies (10 mg/kg every 2 weeks), then decisions on how to proceed will be based on safety, tolerability, and PK data; and will be agreed between the investigators and the sponsor.

[00326] Dose level -1 (anti-FGFR2-IIIb 6 mg/kg every 2 weeks; 3 to 6 subjects) will only be recruited if ≥ 2 EBRT occurs at dose level 1.

Dose escalation in a cohort

[00327] Part 1 does not allow for dose escalation to a patient.

[00328] In Part 2, patients will be treated in the RD defined in Part 1 and dose escalation will not be allowed.

Dose interruption during drug infusion

[00329] Anti-FGFR2-IIIb antibody infusion should be stopped if a grade ≥3 AE occurs during infusion. If a patient develops bronchospasm or shortness of breath during the infusion, the infusion should be discontinued. Symptoms of infusion reactions may include: fever, chills, muscle stiffness, urticaria, hypotension and hypertension with headache, wheezing, dyspnoea, hypoxia, and pulmonary infiltrates.

[00330] In addition, at the discretion of the investigator, the infusion rate may be reduced or the infusion stopped if a less severe AE (grade 1 or 2) occurs during the infusion. If a grade 3 or less AE resolves within 4 hours, the infusion may be restarted at half the rate. If the same AE of the same severity occurs again during a restarted infusion, the infusion should be discontinued and no further dosing of study drug will be administered without consultation with the sponsor or sponsor's designee.

[00331] If a patient experiences an infusion reaction prior to completion of the infusion, the infusion should be stopped and the patient should be promptly treated and monitored according to signs and symptoms and local clinical protocol until complete resolution of the event. For patients whose infusion-related events were Grade 1 or 2 and resolved completely on the day of the infusion, the infusion may be restarted at the discretion of the investigator at a slower rate with premedication. All subsequent infusions for this patient should then be administered at a reduced infusion rate with premedication. Premedication may include drugs such as corticosteroids, diphenhydramine, acetaminophen, and/or bronchodilators, depending on the indication. Anti-FGFR2-IIIb antibody will be permanently discontinued for patients who experience grade 3 or higher infusion-related adverse events, as well as for patients who have recurrent infusion-related reactions after resuming the infusion despite premedication and a slower infusion rate.

[00332] If a patient experiences an infusion reaction, the patient's vital signs (temperature, blood pressure, pulse, and respiratory rate) should be monitored during the infusion, as well as every 30 minutes after the infusion for at least 2 hours and until the infusion reaction resolves.

[00333] Dose interruptions and delays due to mFOLFOX6 toxicity are described in Table 4 (see product labeling for leucovorin, 5-FU, and oxaliplatin).

Parameters and methods of evaluation

Security Options

[00334] Safety measures will include AEs, hematology, biochemistry, urinalysis, vital signs, body weight, use of concomitant medications/procedures, ECOG general health score, targeted physical examinations, ECG, and ophthalmic examinations.

1.1 Tumor analysis for patient selection

1.1.1 Part 1

[00335] Eligible patients in Part 1 have non-selective gastrointestinal cancer (with or without tumors overexpressing FGFR2b) with unresectable, locally advanced, or metastatic disease and are candidates for both anti-FGFR2-IIIb antibodies and chemotherapy regimen mFOLFOX6. FGFR2 status will be determined retrospectively using IHC and blood-based biopsy.

1.1.2 Part 2

[00336] Patients in Part 2 of this study must consent to tumor tissue analysis and blood testing. Patients will be selected for inclusion based on FGFR2b overexpression and/or FGFR2 amplification as determined by a validated IHC or blood-based biopsy assay, respectively. Patients who do not demonstrate FGFR2b overexpression on IHC or amplification on blood-based biopsy analysis will not be eligible for inclusion; however, a positive result on one or both of the assays is sufficient to satisfy the eligibility requirements (eg, positive on a blood-based biopsy but negative on an IHC). It is the responsibility of each researcher to obtain an adequate tumor sample for analysis of FGFR2b overexpression for registration. Instructions for handling, labeling, and shipping of a tumor slide specimen or tumor block are detailed in the laboratory manual that will be distributed with the specimen collection kit.

[00337] Third party laboratories will perform analysis of FGFR2b expression and FGFR2 amplification using a validated IHC and blood-based assay, respectively.

[00338] For Part 2, as soon as tumor and blood samples are obtained, the analysis will be performed as efficiently as possible, and the results will be reported to the investigator or authorized person.

1.2 Fresh tumor biopsy for pharmacodynamic analysis

1.2.1 Part 2 only

[00339] Tumor biopsy samples are also collected to evaluate the pharmacodynamic effect of anti-FGFR2-IIIb antibodies on the tumor microenvironment. These biopsy specimens will be obtained before and after treatment to study immune infiltrates and the expression of selected tumor markers. Additional biopsies can also be obtained from tumors that have responded and/or progressed before or after treatment to understand the mechanisms of resistance. Tumor biopsy specimens can be assessed for expression of immune or disease-associated genes and/or proteins, and for the presence of immune cell populations using a variety of methodologies including, but not limited to, IHC, qRT-PCR, genetic mutation detection, and fluorescent in situ hybridization (FISH). These samples can also be subjected to RNA sequencing to determine the effect of the FGFR2-IIIb antibody on gene expression pathways, as well as to identify gene expression signatures associated with response or resistance to response. These tests can help predict future response to treatment. Other methods for expressing tumor biomarkers are also being evaluated.

[00340] A fresh biopsy of the primary tumor or metastatic tumor site is mandatory, to the extent possible, for up to 30 patients randomized to Part 2 at screening (at least 24 hours prior to dosing) and during treatment within 7 days prior to cycle 3, day 1 (and at least 24 hours before dosing). For patients who were biopsied 12 weeks prior to enrollment, this sample may qualify for a new pre-treatment biopsy provided an adequate sample for PD analysis (one paraffin block or approximately 10 slides) is available.

[00341] Patients in Part 2 may also undergo an additional biopsy during treatment after a documented tumor response, within 28 (±7) days after tumor evaluation. Patients in Part 2 may also have an additional post-treatment biopsy during an EOT visit after documented tumor progression. In each case, consultation with the sponsor should take place before the biopsy is performed. Both biopsies are optional.

[00342] The investigator should evaluate the possibility of obtaining a fresh tumor sample at each time point, and this should include consideration of patient safety. If the investigator considers that a biopsy cannot be performed, then this determination should be recorded in the source documents.

[00343] The lesions from which the biopsy was taken may become inflamed, bleed, or change in size, which may lead to inaccurate tumor measurements. Therefore, it is highly recommended not to use the lesions from which the biopsy was taken as a target for response assessment according to the RECIST v 1.1 criteria. These biopsy specimens should be taken by excisional, incisional, or punch biopsy. Fine needle aspirates or other cytological specimens are not sufficient for subsequent biomarker analysis. Tumor tissue samples in the form of a paraffin block or unstained slides will be submitted for central evaluation by IHC.

1.3 Tumor assessments

[00344] Evaluation of tumors should consist of clinical examination and appropriate imaging modalities (preferably computed tomography with appropriate slice thickness according to RECIST v1.1); other evaluations (MRI, radiography, PET and ultrasound) may be performed if necessary. The same methods that were used to detect lesions at baseline should be used to track the same lesions throughout the clinical trial. Tumor screening scans should be performed within 2 weeks of starting treatment on Day 1 of Cycle 1.

[00345] Evaluation of tumor response will be performed both by the investigator and by blinded central radiological examination in accordance with RECIST 1.1 guidelines.

[00346] Tumor scans will be performed during screening (during 2 weeks of cycle 1, day 1 in parts 1 and 2) and for 7 days prior to cycle day 1 4, cycle day 1 7, cycle day 10, day 1 cycle 13 and then approximately every 12 weeks. If CR or PR is noted, a confirmatory scan should be performed 4 to 6 weeks later.

[00347] Upon discontinuation of investigational treatment for reasons other than progression or withdrawal of consent, tumor evaluations will be conducted until the patient begins to receive additional anti-cancer therapy or progression.

1.3.1 Blood based biopsy (cDNA)

[00348] In Part 1, samples for blood-based biopsy analysis (coDNA) will be collected prior to the first dose of study drug (cycle 1 day 1) and analyzed retrospectively for FGFR2 amplification.

[00349] In Part 2, a blood-based biopsy (cDNA) analysis will be performed prior to screening. This sample will be analyzed prospectively for FGFR2 amplification. In addition, blood-based biopsy (coDNA) analyzes will be collected longitudinally every 6 weeks from the first dose for 24 weeks and then approximately every 12 weeks thereafter and analyzed retrospectively for FGFR2 amplification. A sample will also be collected during the EOT visit from all Part 2 patients.

1.4 Pharmacodynamic analysis of biomarkers using hair follicles

[00350] In Part 1 only, hair follicles (approximately 10 if present) from the eyebrows or scalp will be collected from all eligible patients. Hair follicles are known to express the FGFR2b receptor, and changes in FGFR2b levels and downstream signaling can be used to correlate the dose of anti-FGFR2-IIIb antibody required to effectively block FGFR2b receptors and downstream signaling and may help guide selection of an RD for part 2 of the study. .

1.5 Pharmacodynamic analysis of biomarkers using blood

[00351] Serum samples for analysis of exploratory biomarkers of the FGFR pathway (eg: FGF7, FGF10) will be collected from all patients prior to dosing at the time points specified in Appendix 3.

1.6 Blood sample for ctDNA

1.7 Pharmacodynamic analysis of biomarkers using tumor biopsy

[00352] Levels of immune cell infiltrate and other exploratory biomarkers in tumor biopsy samples will be analyzed before and after treatment in all patients.

1.8 FCGR polymorphism

[00353] Blood samples are also collected to detect polymorphisms that are often found in Fc-gamma receptors, such as FCGR2A and FCGR3A . These genes express Fc-gamma receptors on leukocytes, which are integral to the ADCC pathway, which is the expected mechanism of action for an anti-FGFR2-IIIb antibody. Data will be collected for post-study analysis at the completion of the study to correlate the patient's response to anti-FGFR2-IIIb antibodies. These biomarker assays are considered exploratory.

1.9 Quality of life scales

[00354] The EQ-5D-5L Quality of Life (QoL) Questionnaire and EORTC QLQ-C30 will be applied several times prior to dosing (see Annex 1 for time points).

[00355] The EQ-5D-5L questionnaire was developed by the EuroQol Group, and is a standardized measure for providing clinical and economic evaluation aids. It uses a descriptive system and a visual analogue scale (VAS). The descriptive system has 5 categories: mobility, self-care, routine activities, pain/discomfort, and anxiety/depression, and each category has 5 levels: no problem, slight problem, moderate problem, serious problem, and extremely serious problem.

[00356] Respondents are asked to indicate their state of health by ticking the most appropriate statement in each of the 5 categories. The numbers for the 5 categories can be combined into a 5-digit number describing the health status of the respondent. The health states defined by the EQ-5D-5L descriptive system are converted into one index value for the calculation of aids. The VAS displays the respondent's self-reported health on a vertical 20 cm VAS scale with endpoints labeled "best health you can imagine" and "worst health you can imagine".

[00357] The European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ) is an integrated system for assessing the health-related quality of life of cancer patients participating in international clinical trials. The EORTC uses a modular quality of life approach consisting of a core questionnaire (EORTC QLQ-C30) to be applied as needed with a module specific to tumor site, treatment modality or quality of life measurement (e.g. specific to gastric cancer is module QLQ-STO22).

[00358] The patient responds on five functional scales (physical, role, emotional, social and cognitive), three symptom scales (fatigue, nausea and vomiting, and pain) and a global health/quality of life scale and six single measures (dyspnea, insomnia, loss of appetite, constipation, diarrhea and financial difficulties).

1.10 General condition indicator according to ECOG

[00359] The ECOG General Condition Score will be assessed in all patients at the times specified in Appendix 1. The ECOG General Condition Score is a scale used to assess how a patient's disease progresses, to assess how the disease affects the daily life of the patient, and to determine the appropriate treatment and prognosis. The ECOG scale is shown in Appendix 4.

1.11 Pharmacokinetic parameters

[00360] Blood samples to determine the concentration of antibodies to FGFR2-IIIb in serum will be collected from each patient, as indicated in the study flowchart for the collection of blood samples for analysis of pharmacokinetics, immunogenicity and pharmacodynamics (Appendix 3).

2. Conducting research

2.1 Overview of patient ratings

[00361] A schedule of detailed patient assessments is provided in Appendix 1. A list of laboratory safety assessments is provided in Appendix 2. Instructions for sampling and processing of PK, PD and immunogenicity data are provided in the flowchart in Appendix 3.

2.2 Assessments and procedures within the study visit

2.2.1 Pre-screening period (only part 2 - pre-study)

[00362] Written, signed informed consent (FIS pre-screening) must be obtained prior to any study-specific procedures.

Prospective IHC analysis of FGFR2b expression and blood test demonstrating FGFR2 amplification (see above).

2.2.2 Screening period (from day -14 to day 0)

[00363] Written, signed informed consent must be obtained prior to any study-specific procedures. Patients who have fully agreed to participate in the study will undergo screening evaluations within 14 days (2 weeks) prior to the first infusion of anti-FGFR2-IIIb antibodies. The following procedures will be followed:

Consideration/confirmation of acceptance criteria

Medical and medical history, including drug history

Collection of tumor tissue from the archive or newly obtained material (required for registration in part 1 and part 2 )

Demographic and background characteristics

Complete physical examination, including measurement of weight and height

Assessment of the indicator of general condition according to ECOG

Measurement of vital signs (blood pressure, pulse, respiration and body temperature [°C])

12-lead ECG after 5 minutes of rest before recording

Comprehensive ophthalmological examination

Safety blood tests (See Appendix 2.)

Serum pregnancy test (beta-human chorionic gonadotropin [β-HCG]), ≤72 hours for women of childbearing potential.

Urinalysis (includes test strips for protein, glucose, blood, pH, and ketones)

Tumor assessments performed within 14 days prior to treatment, including clinical examination and appropriate imaging modalities, with other assessments (MRI, X-ray, PET, and ultrasound) performed as needed.

Randomization for Part 2 Patients Only

For up to 30 patients randomized to Part 2: Fresh tissue biopsy at the site of the primary or metastatic tumor at least 24 hours prior to dosing. For patients who were biopsied 12 weeks prior to enrollment, this sample may qualify for a new pre-treatment biopsy provided an adequate sample for PD analysis (one paraffin block or approximately 10 slides) is available.

Collection of blood-based biopsy specimens (coDNA) as outlined in Annex 3.

FOLFOX administration (For Part 1 , patients may start mFOLFOX6 chemotherapy prior to enrollment and must be a candidate for at least 2 cycles of mFOLFOX6 chemotherapy to be eligible. In Part 2, patients must have completed 2 cycles of mFOLFOX6 chemotherapy prior to study entry. randomization).

Reporting AEs, if applicable

2.2.3 Treatment period

2.2.3.1 Cycle 1, day 1

[00364] The following procedures will be performed:

Consideration/confirmation of acceptance criteria

Update of medical history, medical history, and drug history to record any changes since screening

Limited physical examination including weight measurement and oral examination

Patient Evaluation Results (EQ-5D-5L and EORTC QLQ-C30)

Measurement of vital signs (blood pressure, pulse, respiration, and body temperature [°C]) before dosing and 0.5, 1, 2, and 4 hours after starting anti-FGFR2-IIIb antibody infusion

Safety blood tests, with results obtained within 72 hours prior to study drug administration, to confirm eligibility (see Appendix 2)

Serum pregnancy test (β-HCG), ≤72 hours prior to dosing for women of childbearing potential.

Urinalysis (includes test strips for protein, glucose, blood, pH, and ketones)

Blood collection for PK analyses, immunogenicity assays, FCGR, ctDNA and biomarker assays as described in Appendix 3.

Collection of blood-based biopsy specimens (coDNA): In Part 1, a blood-based biopsy specimen (coDNA) will be collected prior to entry into Cycle 1 Day 1 for retrospective analysis. Samples are not required from Part 2 patients at this time.

In Part 1 only, scalp or eyebrow hair follicle samples (approximately 10, if any) will be collected prior to dosing on the first day of Cycle 1 in all patients eligible for sampling.

AE reports

Overview of concomitant drug therapy

[00365] Investigational drug administration:

Anti-FGFR2-IIIb antibodies are administered by intravenous infusion over 30 minutes

Chemotherapy according to the mFOLFOX6 regimen is administered after 30 minutes of rest

2.2.3.2 Cycle 1, day 2

[00366] The following procedures will be performed:

Measurement of vital signs (blood pressure, pulse, respiration, and body temperature [°C]) before dosing and 0.5, 1, and 2 hours after starting anti-FGFR2-IIIb antibody infusion

Blood samples for PK analysis, exploratory biomarker analysis will be collected as described in Annex 3.

mFOLFOX6 introduction continues

AE reports

Overview of concomitant drug therapy

2.2.3.3 Cycle 1, day 3

[00367] The following procedures will be performed:

Measurement of vital signs (blood pressure, pulse, respiration, and body temperature [°C]) before dosing and 0.5, 1, and 2 hours after starting anti-FGFR2-IIIb antibody infusion

Blood sampling for PK analysis as described in Appendix 3.

mFOLFOX6 introduction continues

AE reports

Overview of concomitant drug therapy

2.2.3.4 Cycle 1, day 8

[00368] The following procedures will be performed:

Limited physical examination including weight measurement and oral examination

Measurement of vital signs (blood pressure, pulse, respiration, and body temperature [°C]) before dosing and 0.5, 1, and 2 hours after starting anti-FGFR2-IIIb antibody infusion

Safety blood tests, with results obtained within 72 hours prior to study drug administration (see Appendix 2)

Blood sampling for PK analysis as described in Appendix 3.

AE reports

Overview of concomitant drug therapy

2.2.3.5 Cycle 2, day 1

[00369] The following procedures will be performed:

Limited physical examination including weight measurement and oral examination

Measurement of vital signs (blood pressure, pulse, respiration, and body temperature [°C]) before dosing and 0.5, 1, and 2 hours after starting anti-FGFR2-IIIb antibody infusion

Safety blood tests, with results obtained within 72 hours prior to study drug administration (see Appendix 2)

Blood sample for PK analysis, immunogenicity analysis and biomarker analysis as described in Appendix 3.

AE reports

Overview of concomitant drug therapy

[00370] Investigational drug administration:

Antibodies to FGFR2-IIIb were administered by intravenous infusion over 30 minutes

mFOLFOX6 chemotherapy is administered after 30 minutes of rest

2.2.3.6 Cycle 3, day 1 and day 1 of subsequent odd cycles

[00371] At the end of the EBRT period, patients may continue to receive anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 administered every 2 weeks in 14-day cycles until radiological or clinical confirmation of disease progression as assessed by the investigator, unacceptable toxicity occurs, or until the patient meets any of the other exclusion criteria specified in the protocol. There is no maximum dose of anti-FGFR2-IIIb antibody. Continued administration of the mFOLFOX6 regimen after the EBRT period will be conducted according to the regional standard of care.

[00372] The following procedures will be performed:

Limited physical examination including weight measurement and oral examination

Assessment of the indicator of general condition according to ECOG

Patient Evaluation Results (EQ-5D-5L and EORTC QLQ-C30)

Measurement of vital signs (blood pressure, pulse, respiration, and body temperature [°C]) performed before dosing and 0.5, 1, and 2 hours after the start of anti-FGFR2-IIIb antibody infusion

Comprehensive ophthalmological examination

Slit lamp studies without OCT for patients in Part 1 and for patients in Part 2 randomized to receive antibodies to FGFR2-IIIb and FOLFOX 6; every 6 weeks after cycle 2, day 1 (until cycle 3, day 15, cycle 5, day 1 and cycle 6, day 15), and then every 12 weeks after cycle 6, day 15. Continue every 6 to 8 weeks if the patient has any persistent corneal disease.

Safety blood tests, with results obtained within 72 hours prior to study drug administration (see Appendix 2)

Urinalysis for pregnancy ≤72 hours prior to dosing for women of childbearing potential.

Urinalysis (includes test strips for protein, glucose, blood, pH, and ketones)

Tumor assessments performed within 7 days of Cycle 1 day 3 and including clinical examination and appropriate imaging modalities, with other assessments (MRI, X-ray, PET, and ultrasound) performed as needed

A fresh biopsy of the primary tumor or metastatic tumor site is mandatory, as far as possible, within 7 days to day 1 of cycle 3 (and at least 24 hours before dosing) in about 30 patients randomized to Part 2.

Blood collection for PK analyses, immunogenicity assays, blood-based biopsy (cDNA) and biomarker assays as described in Appendix 3.

In Part 2, a blood-based biopsy (cDNA) sample will be collected prior to treatment.

Scalp or eyebrow hair follicle samples (~10 if available)

AE reports

Overview of concomitant drug therapy

[00373] Investigational drug administration:

Anti-FGFR2-IIIb antibodies are administered by intravenous infusion over 30 minutes on day 1 of each cycle

Chemotherapy according to the scheme mFOLFOX6 is administered after the introduction of antibodies to FGFR2-IIIb on day 1 of each cycle after 30 minutes of rest.

2.2.3.7 Cycle 4, day 1 and day 1 of subsequent even cycles

[00374] The following procedures will be performed:

Limited physical examination including weight measurement and oral examination

Patient Evaluation Results (EQ-5D-5L and EORTC QLQ-C30)

Measurement of vital signs (blood pressure, pulse, respiration, and body temperature [°C]) before dosing and 0.5, 1, and 2 hours after starting anti-FGFR2-IIIb antibody infusion

Slit lamp studies without OCT for patients in Part 1 and for patients in Part 2 randomized to receive antibodies to FGFR2-IIIb and FOLFOX 6; every 6 weeks after cycle 2, day 1 (until cycle 3, day 15, cycle 5, day 1 and cycle 6, day 15), and then every 12 weeks after cycle 6, day 15. Continue every 6 to 8 weeks if the patient has any persistent corneal disease.

Safety blood tests, with results obtained within 72 hours prior to study drug administration (see Appendix 2)

Tumor assessments performed within 7 days prior to cycle 4 day 1 and including clinical examination and appropriate imaging modalities, with other assessments (MRI, radiography, PET, and ultrasound) performed as needed

In Part 2, a blood-based biopsy (cDNA) sample will be collected prior to treatment.

In Part 1, a blood sample for PK analysis will be taken ≤4 hours before the dose of anti-FGFR2-IIIb antibodies and 15 minutes (± 10 minutes) after the end of the infusion of anti-FGFR2-IIIb antibodies for subsequent cycles. For Part 2, samples for PK analysis must be collected (only for patients randomized to treatment with anti-FGFR2-IIIb and mFOLFOX6 antibodies) ≤4 hours before dosing with anti-FGFR2-IIIb antibodies and 15 minutes (± 10 minutes) after the end of reporting of anti-FGFR2-IIIb antibody related AEs

AE reports

Overview of concomitant drug therapy

[00375] Investigational drug administration:

Anti-FGFR2-IIIb antibodies are administered by intravenous infusion over 30 minutes on day 1 of each cycle

Chemotherapy according to the mFOLFOX6 scheme is administered after the introduction of antibodies to FGFR2-IIIb on day 1 of each cycle after 30 minutes of rest

2.2.4 End-of-treatment visit or early end-of-study visit

[00376] Patients will return to the study site approximately 28 (±3) days after the last administration of study treatment or in the event of early termination of the patient's participation in the study. The following assessments will be performed during the end-of-treatment visit:

Limited physical examination including weight measurement and oral examination

Assessment of the indicator of general condition according to ECOG

Measurement of vital signs (blood pressure, pulse, respiration and body temperature [°C] after 5 minutes of rest)

12 lead ECG after 5 minutes of rest

Comprehensive ophthalmological examination

Safety blood tests (see Appendix 2)

Urinalysis for pregnancy, for women of childbearing potential

Urinalysis (includes test strips for protein, glucose, blood, pH, and ketones)

Tumor scan, which may be omitted if the last scan was performed less than 6 weeks prior to the EOT visit or if tumor progression was previously determined

Blood sample for immunogenicity testing

Part 2 only will take a blood-based biopsy sample (cDNA)

Scalp or eyebrow hair follicle samples (~10 if available)

Blood sample for PK analysis for all patients in Part 1 and all patients receiving anti-FGFR2-IIIb antibodies in Part 2

Blood sample for biomarker evaluation

AE reports

Overview of concomitant drug therapy

[00377] Note: Upon discontinuation of investigational treatment for reasons other than progression or withdrawal of consent, tumor evaluations will continue until the patient is on additional cancer therapy or until progression occurs.

2.2.5 Long-term follow-up

Patients in both Part 1 and Part 2 will undergo an extended period of follow-up for survival through clinic or telephone visits approximately every 3 months ± 28 days after the EOT visit, up to 24 months after the last patient entered the study. or until death, loss to follow-up, withdrawal of consent, or termination of the study by the sponsor (whichever comes first).

During the follow-up period, if the patient is undergoing anti-cancer therapy, this should be documented.

During the first 6 months of the follow-up period, any pregnancy should be reported to the sponsor.

Patients must be monitored until death, loss for follow-up, withdrawal of consent, or termination of the study by the Sponsor.

Serious AEs occurring after the EOT visit should be reported by the Investigator to the Sponsor if the Investigator believes there is a causal relationship with the investigational product.

3. Statistical methods

[00378] Before locking the database, a separate statistical analysis plan (SAP) will be drawn up with a detailed description of the analysis methods presented below. Any deviations from the planned analyzes will be described and justified in the final study summary report.

3.1 Study patients

3.1.1 Patient distribution

[00379] The number and percentage of patients entering and completing each phase (eg, screening, cycle 1, and subsequent cycles, if any) of the study will be presented. The reasons for the withdrawal will also be summarized.

3.1.2 Protocol deviations

[00380] A summary of the number and percentage of patients with major protocol deviations by type of deviation will be provided. Deviations will be determined by SAP before the database is locked.

3.1.3 Populations analyzed

[00381] The following analysis populations are defined for the study:

Safety assessment populations are all patients who received any fraction of at least one dose of anti-FGFR2-IIIb antibodies.

The ESWL population being assessed is all patients included in Part 1 of the study who received at least 2 doses of anti-FGFR2-IIIb antibodies and completed cycle 1 of treatment, or experienced ESWL in cycle 1.

The PK assessment population is all patients who received at least one dose of anti-FGFR2-IIIb antibodies and had adequate PK assessments performed to determine the PK profile. Adequacy will be determined on a case-by-case basis and will be assessed prior to analysis of blood samples.

Assigned to treatment (ITT) population - all registered patients

Efficacy-Based Population - All patients who met eligibility criteria received at least 1 dose of anti-FGFR2-IIIb antibodies and had at least 1 post-baseline disease assessment

3.2 General considerations

[00382] The total number of participants scheduled for this study is approximately 372 patients. Part 1 will include up to 12 patients being evaluated for any type of EBRT according to a standard 3+3 design.

[00383] In Part 2, efficacy and tolerability will be studied by enrolling approximately 360 patients with FGFR2b-selective gastric cancer randomized in a 1:1 ratio to receive antibodies to FGFR2-IIIb in combination with mFOLFOX6 or placebo and in combination with mFOLFOX6. Eligible patients will be stratified according to geographic region (US and EU, Asia or the rest of the world), previous treatment status (de novo or adjuvant/neoadjuvant), and measurable disease status (measurable or non-measurable).

Power and sample size

[00384] This assay is intended to provide adequate power for primary PFS analysis.

[00385] Based on mPFS for patients treated with placebo and mFOLFOX6 for 6 months, approximately 156 patients (randomized 1:1) with a target of 96 PFS events should demonstrate a hazard ratio (HR) of 0.5 for mPFS with a power of 90 % (2-tailed α = 0.05) for the combination of anti-FGFR2-IIIb and mFOLFOX6 antibodies compared to placebo and mFOLFOX6 at 24 months post-inclusion and 6 months follow-up.

[00386] Assuming an exponential distribution of PFS, this corresponds to an increase in mean PFS from 6 to 12 months. In the current design, the minimum observed effect that would result in statistical significance for PFS is a 50% improvement (HR=0.67) from 6 to 9 months.

[00387] This study is also designed for primary analysis of OS.

[00388] Based on mOS for patients treated with placebo and mFOLFOX6 for 10 months, enrollment in the study will continue to approximately 360 patients with a target of 249 deaths to demonstrate an HR of 0.7 for mOS with a power of 80% with an overall error rate type I 0.05 for the combination of antibodies to FGFR2-IIIb and mFOLFOX6 compared with placebo and mFOLFOX6 at 36 months after inclusion and 10 months of follow-up after registration of the last patient. The group sequential method will be used to allocate type I error rates based on O'Brien-Fleming cut-off criteria and type II error rates based on a family of gamma distributions with parameter -4 in the intermediate and final OS analysis.

[00389] Assuming an exponential distribution of OS, this corresponds to a 43% increase in median OS from 10 to 14.3 months. In the current design, the minimum observed effect that would result in statistical significance for OS in the final analysis is a 28% improvement (HR=0.78) from 10 to 12.8 months.

[00390] Power and sample size estimates were evaluated using ^EAST® (V6.4).

3.3 Demographics, baseline characteristics, and concomitant drug therapy

[00391] Demographics, medical history, comorbidities, and concomitant drug therapy will be summarized by cohort and as a whole. Appropriate tables and lists will be provided to determine if the criteria for conducting a study are met. These will include descriptions of patients who did not meet eligibility criteria, assessment of protocol violations, study drug accounting, and other data that may affect the overall conduct of the study.

[00392] Characteristics at baseline will be generalized to the safety assessment population. Patients who died or left the study prior to initiation of treatment, or who did not complete the necessary safety studies, will be described and evaluated separately.

3.4 Treatment adherence

[00393] Treatment administration will be summarized by cohort, including dose administration, dose changes or deferrals, cumulative dose, mean dose, number of infusions, and duration of therapy.

3.5 Performance analyzes

[00394] In Part 1, all analyzes will be descriptive and will be presented by dose groups and generally as needed. Descriptive statistics will include number of observations, mean, standard deviation, median, range, and interquartile breadth for continuous variables, and number and percentage for categorical variables; 95% confidence intervals will be presented where appropriate.

3.5.1 Primary effectiveness analysis

[00395] In Part 2, the primary efficacy analysis is a comparison of PFS in patients treated with anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 or placebo and mFOLFOX6.

[00396] The primary endpoint, PFS, is defined as the time from randomization to the date of radiological confirmation of disease progression based on investigator assessment (according to RECIST v.1.1) or death from any cause, whichever comes first. Secondary efficacy endpoints include OS and ORR.

[00397] An interim analysis and a primary analysis of PFS will be performed and both will be based on phenomena. Only an interim PFS test will be performed at an interim analysis after 48 events (50% of the target 96 PFS events for the primary PFS analysis) seen in enrolled patients to rule out HR > 0.806 for the combination of anti-FGFR2-IIIb and mFOLFOX6 antibodies versus placebo and mFOLFOX6 . It is estimated that an interim analysis will be conducted approximately 20 months after the first patient is included.

[00398] The primary analysis of PFS will be conducted after at least 96 PFS events have been recorded in the first 156 registered patients, and will be performed using an intent-to-treat (ITT) patient population.

[00399] The primary analysis will include cases of radiologically confirmed progression as determined by the investigator according to RECIST v.1.1, and deaths.

[00400] Primary PFS analysis will be performed using a stratified log-rank two-tailed test with a significance level of 0.05. The stratification factors will be the same as for randomization schedule stratification as described in the Interactive System Allowing Phone Call and Internet Access (IXRS).

[00401] If the p-value for the stratified log-rank test is statistically significant (<0.05, two-tailed) and HR<1, the null hypothesis of no difference in PFS will be rejected and a conclusion will be made that PFS is statistically extended in the group receiving anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 compared to the group receiving placebo and mFOLFOX6.

[00402] The median PFS and the corresponding 95% confidence interval for each treatment group will be estimated using the Kaplan-Meier method. The hazard ratio (HR=λanti-FGFR2-IIIb+mFOLFOX6/λmFOLFOX6) will be estimated using a Cox regression model with treatment group as the single main effect and stratification using the same stratification factors as used for the log-rank test. Unstratified HR will also be presented. Secondary OS endpoint analysis will be performed if the primary endpoint, PFS, is statistically significant, and the OS formal hypothesis will be tested hierarchically at the 0.05 level. The Type I error rate for both primary and secondary endpoint testing will be tightly controlled with this fixed-sequence testing procedure at the 0.05 level.

3.5.2 Secondary efficiency analysis

[00403] Analysis of secondary endpoints, including OS and ORR, will be performed if the primary endpoint, PFS, is statistically significant, and the formal hypotheses of OS and ORR will be tested hierarchically at the 0.05 level. OS will be checked first and if it is significant then ORR will be checked. The Type I error rate for primary and secondary endpoint testing will be controlled by this fixed sequence testing procedure at the 0.05 level.

[00404] An interim and final OS analysis is planned if the PFS test is statistically significant. An interim OS analysis will be performed during the initial PFS analysis. In the case of an OS analysis, an OS analysis in the interim (ie, when at least 96 PFS events have been observed) and at the end (ie, when 249 deaths have been observed) will be performed in the ITT population.

[00405] OS hypothesis testing will be performed using a stratified log-rank two-tailed test with a significance level of 0.05. The group sequential method will be used to allocate type I error rates based on O'Brien-Fleming cut-off criteria and type II error rates based on a family of gamma distributions with parameter -4 in the intermediate and final OS analysis. The stratification factors will be the same as for randomization schedule stratification as described in IXRS.

[00406] The median OS and the corresponding 95% confidence interval for each treatment group will be estimated using the Kaplan-Meier method. HR will be estimated using a Cox regression model with treatment group as the single main effect and stratification using the same stratification factors used for the log-rank test. Unstratified HR will also be presented.

[00407] ORR is defined as the proportion of patients with a partial or complete response as determined by the investigator according to RECIST v.1.1. Primary ORR analysis will be performed among patients with measurable disease at baseline. In the analysis of ORR, patients who do not have adequate post-baseline tumor scores will be counted as non-responders. A formal test of the ORR hypothesis will be carried out using the stratified Cochran-Mantel-Haenszel test. The stratification factors will be the same as for randomization schedule stratification as described in IXRS.

3.5.3 Analysis of search performance indicators

[00408] Study efficacy endpoints include duration of response in responding patients, 1-year OS ratio, and change in quality of life from baseline as measured by EQ-5D-5L and EORTC QLQ-C30 for all enrolled patients .

[00409] Duration of response is defined for patients with an objective response as the time from the first radiographic confirmation of an objective response to RECIST 1.1 disease progression or death from any cause. Mean duration of response and associated 95% CI will be estimated by treatment group using Kaplan-Meier methods. Differences between treatment groups will be analyzed using a stratified log-rank test using the same stratification used for randomization.

[00410] The 1-year OS, defined as the proportion of patients alive at time 1 year, will be assessed in the analysis of overall survival using the Kaplan-Meier method. The dispersion of proportions will be estimated using the Greenwood formula. An overall comparison of the difference in 1-year survival between the two treatment groups will be calculated using a z-statistic, where t=1 year.

[00411] For change in quality of life from baseline as measured by the EQ-5D-5L and EORTC QLQ-C30, summary statistics of change from baseline will be presented at each subsequent assessment after baseline and in end of treatment. Differences between treatment groups will be analyzed using repeated measures analysis methods, if applicable.

Blinded Independent Review Committee (BIRC)

[00412] The BIRC will be created to evaluate the correspondence between the investigator's assessment and the BIRC assessment. A predefined audit plan will be included in the imaginary schedule, while the percentage of patients, identification of imaging subgroups, audit criteria for all images, and comparison of local review results and PFS audit results will be detailed.

3.6 Safety analyzes

[00413] The safety analysis will include all patients who receive any study drug (anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 or placebo and mFOLFOX6) during the entire study period, and provide any post-treatment safety information. All AEs will be coded using the Medical Regulatory Dictionary (MedDRA). The investigator will classify the severity of the AE using CTCAE v 4.03.

[00414] An adverse event occurring during treatment (AEEP) is defined as any event with an onset date on or after the date of administration of the first dose of study drug, or any event present before treatment that worsens after treatment. The summary tables will include only NJVL with a date of occurrence before the date of the last dose + 30 days. The number and percentage of patients who experience AEs will be summarized by organ system class, preferred term, causation with study drug, and severity for each treatment group. A patient list will be provided for those patients who experience SAEs, including death, or AEs associated with early withdrawal from the study or discontinuation of study drug. The data of clinical and laboratory analyzes will be summarized by type of laboratory research. The number and percentage of patients who develop abnormalities (i.e., values outside the normal ranges) and/or clinically significant abnormalities following study drug administration will be reported for each clinical laboratory test score. For each clinical laboratory test score, descriptive statistics will be provided for baseline and all subsequent scheduled post-treatment visits. Changes from baseline to post-treatment visits will also be provided. Descriptive statistics on vital signs will also be provided in a similar manner. In addition, by treatment group, shifts from baseline in CTCAE grade (where applicable) and high/low scores (in cases where CTCAE grades are not defined) will be presented. No formal security endpoint comparisons are planned.

3.7 Pharmacokinetic analyzes

[00415] PK parameters will be assessed using non-compartmental analysis, although compartmental analysis may be used if necessary. Individual and mean (± SD) serum anti-FGFR2-IIIb antibody concentration versus time data will be tabulated and plotted against dose level. The PK parameters of anti-FGFR2-IIIb antibodies will be assessed from time-dependent serum concentrations of study drug using non-compartmental assay (NCA) with intravenous infusion. Conciliation of alternative methods may be considered. Assessed individual and mean (± SD) PK parameters will be tabulated and summarized by dose level. Other descriptive statistics can be provided for anti-FGFR2-IIIb serum antibody concentration versus time data and estimated PK parameters. Dose proportionality, accumulation of study drug, and achievement of steady state will be assessed if data permit.

[00416] The impact of immunogenicity on exposure to anti-FGFR2-IIIb antibodies will be evaluated.

3.8 Interim analysis

[00417] An interim analysis of PFS will be performed, in which only a PFS feasibility analysis will be performed after 48 events (50% of the target 96 PFS events for the primary PFS analysis) seen in the first 156 enrolled patients to exclude HR > 0.806 in PFS for the combination antibodies to FGFR2-IIIb and mFOLFOX6 versus placebo and mFOLFOX6. In addition, an interim analysis of OS is planned if the test for PFS is statistically significant. An interim OS analysis will be performed during the initial PFS analysis. If OS is analyzed, an OS analysis in the interim will be performed on the ITT population, and the type I error rate in the interim analysis is determined by applying the Lahn-DeMets modified O'Brien-Fleming cost alpha function as a function of the proportion of information (deaths) at the time of analysis.

[00418] In addition, the safety data will be regularly checked by the sponsor's and CRO's medical monitors. During the dose escalation phase, medical monitors and investigators will review the safety data for each dose cohort prior to dose escalation or dose reduction. AE data from all cycles will be provided to medical monitors when available.

3.9 Changes in scheduled analyzes

[00419] If there are discrepancies between the text of the statistical analysis as planned in the protocol and the final SAP, the amendment to the protocol will not be implemented and the SAP will take precedence.

Links

Andre F, Ranson M, Dean E, Varga A, Van der Noll R, Stockman P, et al. Results of a phase I study of AZD4547, an inhibitor of fibroblast growth factor receptor (FGFR), in patients with advanced solid tumors. Proc AACR abstract, 2013:LB-145.

Brown A, Courtney C, King L, Groom S, Graziano M. Cartilage dysplasia and tissue mineralization in the rat following administration of a FGF receptor tyrosine kinase inhibitor. Toxicol Pathol, 2005;33:449-455.

Cunningham D, Starling N, Rao S, et al. Capecitabine and oxaliplatin for advanced esophagogastric cancer. N Engl J Med. 2008(358): 36-46.

Dienstmann R, Bahleda R, Adamo B et al. First-in-human study of JNJ-42756493, a potent pan fibroblast growth factor receptor (FGFR) inhibitor in patients with advanced solid tumors. Proc AACR 2014: 5446 (abstract).

Fuchs C, Tomasek J, Yong C, et al. Ramucirumab monotherapy for previously treated advanced gastric or gastro-oesophageal junction adenocarcinoma (REGARD): an international, randomised, multicentre, placebo-controlled, phase 3 trial. Lancet Oncol, 2014; 383:31-39.

Garg A, Quartino A, Li J, Jin J, Wada DR, Li H, Cortés J, McNally V, Ross G, Visich J, Lum B. Population pharmacokinetic and covariate analysis of pertuzumab, a HER2-targeted monoclonal antibody, and evaluation of a fixed, non-weight-based dose in patients with a variety of solid tumors. cancer chemotherapy and pharmacology. 2014 Oct 1;74(4):819-29.

Gemo AT, Deshpande AM, Palencia S, Bellovin DI, Brennan TJ et al. anti-FGFR2-IIIb: A therapeutic antibody for treating patients with gastric cancers bearing FGFR2 amplification. Proc AACR 2014: CT325 (abstract).

Han K, Peyret T, Marchand M, Quartino A, Gosselin NH, Girish S, Allison DE, Jin J. Population pharmacokinetics of bevacizumab in cancer patients with external validation. Cancer Chemotherapy and Pharmacology. 2016 Aug 1;78(2):341-51.

Hecht J, Bang Y, Qin S, et al. Lapatinib in combination with capecitabine plus oxaliplatin in human epidermal growth factor receptor 2-positive advanced or metastatic gastric, esophageal, or gastroesophageal adenocarcinoma: TRIO-013/LOGiC - a randomized phase III trial. J Clin Oncol 2015; 34(5):443-451.

Inoue M, Tsugane. Epidemiology of gastric cancer in Japan. Postgrad Med J. 2005; 81(957): 419-424.

Li J, Qin S, Xu J, et al. 2016. Randomized, double-blind, placebo-controlled phase III trial of Apatinib in patients with advanced chemotherapy-refractory or metastatic adenocarcinoma of the stomach or gastroesophageal junction. J Clin Oncol 2016; 34(14):1448-1454.

Miki, T, Bottaro, DP, Fleming, TP et al. Determination of ligand-binding specificity by alternative splicing: Two distinct growth factor receptors encoded by a single gene. Proc. Natl. Acad. sci. USA, 1992;89: 246-250.

National Cancer Institute. SEER Stat Fact Sheets: Esophageal Cancer 2015. Available from http seer (dot) cancer (dog) gov (slash) statfacts (slash) html (slash) esoph (dot) html. Accessed February 25, 2016.

Naylor GM, Gotoda T, Dixon M, et al. Why does Japan have a high incidence of gastric cancer? Comparison of gastritis between UK and Japanese patients. gut. 2006; 55(11): 1545-1552.

Neugat AI, Hayek H, Howe G. Epidemiology of gastric cancer. Semin Oncol 1996;23:281-91.

Sequist LV, Cassier P, Varga A, et al. Phase I study of BGJ398, a selective pan FGFR inhibitor in genetically preselected advanced solid tumors. Proc AACR 2014: CT326 (abstract).

Shinkawa T, Nakamura k, Yamane N, Shoji-Hosaka E, Kanda Y et al. The absence of fucose but not the presence of galactose or bisecting N-acetylglucosamine of human IgG1 complex-type oligosaccharides shows the critical role of enhancing antibody-dependent cellular cytotoxicity. JBC, 2003; 278:3466-3473.

Takahashi T, Saikawa Y, Kitagawa Y. Gastric cancer: current status of diagnosis and treatment. Cancers 2013; 5(1): 48-63.

Thuss-Patience, P., A. Kretzschmar, D. Bichev, et al. Survival advantage for irinotecan versus best supportive care as second-line chemotherapy in gastric cancer- A randomized phase III study of the Arbeitsgemeinschaft Internistische Onkologie (AIO). Eur J Cancer 2011; 47:2306-2314.

Turner N, Grose R. Fibroblast growth factor signaling: from development to cancer. Nature, 2010;10:116-129.

Ueda S, Hironaka S, Yasui H, et al. Randomized phase III study of irinotecan (CPT-11) versus weekly paclitaxel (wPTX) for advanced gastric cancer (AGC) refractory to combination chemotherapy (CT) of fluoropyrimidine plus platinum (FP): WJOG4007 trial, J Clin Oncol (Meeting Abstracts). 2012, vol. 3

Waddell T, Verheij M, Allum W, Cunningham D, Cervantes A, Arnold D. Gastric cancer: ESMO-ESSO-ESTRO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Annals of Oncology. 2013 Oct 1;24(suppl 6):vi57-63.

Wu, Y-M, Su, F, Kalyana-Sundaram S, Identification of Targetable FGFR Fusions in Diverse Cancers. Cancer Discovery, 2013;3:636-647.

List of abbreviations and definitions

Abbreviation Definition ADCC antibody-dependent cell-mediated cytotoxicity AE adverse event AIDS acquired immunodeficiency syndrome ALT alanine aminotransferase ACHN absolute neutrophil count AST aspartate aminotransferase AUC area under the serum drug concentration versus time curve AUC _τ AUC during τ β-hCG β-human chorionic gonadotropin CHO Chinese hamster ovary DI confidence interval CL clearance _Cmax maximum serum concentration CNS central nervous system CRC Steering Committee for Cohort Evaluation CRO contract research organization CT CT scan CTCAE Standard terminological criteria for adverse events ctDNA circulating tumor DNA C _through maximum serum concentration C _{through ss} maximum concentration at steady state DLT dose-limiting toxicity DMC Data Monitoring Committee DOR response duration DPD dipyrimidine dehydrogenase EAP etoposide/doxorubicin/cisplatin ECF epirubicin/cisplatin/5-FU ECG electrocardiogram ECOG Eastern Cooperative Oncology Group eCRF electronic individual registration cards ELF etoposide/leucovorin/5-FU ELISA linked immunosorbent assay EORTC European Organization for Research and Treatment of Cancer EOT end of treatment eSAE electronic reporting of SAEs 5-FU 5-fluorouracil FAM 5-FU, 3 doxorubicin and mitomycin C FAMTX 5FU/Doxorubicin [Adriamycin]/Methotrexate) FGF fibroblast growth factor FGFR fibroblast growth factor receptor FISH fluorescence in situ hybridization FP 5-FU/cisplatin FRS2 substrate 2 FGF receptor RJ stomach cancer GCP Good Clinical Practice G-CSF Granulocyte colony stimulating factor GEO gastroesophageal junction gastrointestinal tract gastrointestinal GLP NLP - Good Laboratory Practice HFc-G1 human IgG1 HIV AIDS virus HNSTD highest, non-hazardous toxic dose HR risk ratio IB Explorer Brochure FIS Informed Consent Form ICH International Conference on Harmonization ID identification IEC Independent ethics committee IGH immunohistochemistry INP investigational new drug INR international normalized ratio IP investigational drug IRB Expert Council of a medical institution IRC Independent Review Committee ITT population of patients with prescribed treatment i/v i/v IXRS interactive system that allows access by phone call and via the Internet LLOQ lower limit of quantitation LV (delete) mFOLFOX6 modified FOLFOX regimen (infusion 5-fluorouracil, leucovorin, and oxaliplatin) mOS Medium OS MRI Magnetic resonance imaging MTD maximum tolerated dose MTX (delete) NCA non-compartmental analysis NCI National Cancer Institute OCT optical coherence tomography ORR frequency of objective responses OS overall survival FD pharmacodynamic PAT positron emission tomography PFS progression-free survival FC pharmacokinetic PRO patient evaluation results Q2W two times a week QLQ quality of life questionnaire QOL the quality of life RD recommended dose RECIST Response Evaluation Criteria for Solid Tumors RPE retinal pigment epithelium SAE serious adverse event SAP statistical analysis plan SD standard deviation t1/2 terminal half-life TEAE an adverse event that occurred during treatment TIC tyrosine kinase inhibitor TS thymidylate synthase VPN upper limit of normal VAS visual analog scale

Table 5: Evaluation of Anti-FGFR2-IIIb Antibody Pharmacokinetic Parameters (Mean ± SD) Using Non-Compartment Assay for Patients Enrolled in the Anti-FGFR2-IIIb-001 Part 1 Study After First Dose

Part of the study Dose (mg/
kg) Number of patients in the study C _{max 1} (µg/ml) C _{max 1} /dose (µg/ml/mg) C _{through 1}
(µg/ml) AUC _last
(day*
mcg/ml) AUC _last /dose
(day*mk/
ml)/mg) t _½ (day) 1A 0.3 3 7.96±1.15 0.278±0.0511 OK 28.4±9.36 0.976 ± 0.265 2.97±0.510 1 4 22.2±6.13 0.248±0.0876 3.57± ^1.07a 115±36.2 1.29±0.515 6.01±0.646 3 3 71.5±18.2 0.312±0.0654 12.8±2.96 355±82.5 1.55±0.290 8.36±0.816 6 3 136±17.2 0.287±0.0279 19.2±3.36 672±83.5 1.43±0.237 6.70±0.831 10 3 287±7.23 0.410±0.0321 43.5±23.4 1316±340 1.86±0.412 7.80±2.44 15 3 393±185 0.385±0.149 56.4±31.6 1711±310 1.70±0.146 ^6.08b 1B 3 1 52.5 0.49 9.22 ND ND ND 6 1 77 0.232 21.6 529 1.59 11.7 10 6 ^c 163±43.5 0.299±0.0669 35.3±14.5 885±191 1.65±0.406 6.97± ^3.01d

Note. C _{max 1} =maximum observed serum concentration after the first dose; C _{max 1} /dose=C _{max 1} normalized to the administered dose; C _{trough 1} = observed serum concentration at the end of the first dosing interval; AUC _last = area under the observed concentration-time versus time curve of dosing to the last quantifiable concentration after the first dose; AUC _last /Dose=AUC _last , normalized to administered dose; and t _1/2 =final half-life.

NC=summary statistic that cannot be represented as 2 out of 3 patients with C _{trough 1} below LLOQ; ND=FK is a parameter that cannot be accurately determined. ^a n=3. Data from 1 patient could not be reported because the patient's enrollment was terminated without obtaining C1D15 data from the study; ^bn =2. End-phase characteristics were obtained for less than one half-life in 1 of 3 patients. Therefore, the data for this patient were excluded from the summary statistics for half-life, as provided in the data analysis plan; ^c One of 6 patients in the study received a partial dose and parameters were excluded from pooled statistics; and ^dn =3. End-phase characteristics were obtained for less than one half-life in 2 of 5 patients. Therefore, these patients were excluded from the summary statistics for half-life, as provided in the data analysis plan.

Annex 1: Evaluation Schedule - Introductory Phase for Dose Escalation Safety Evaluation (Part 1) and Dose Expansion (Part 2)

Procedure ^a Pre-screening period (Part 2 only) Screening Study treatment:
Cycles 1 and 2 Study treatment:
Cycle 3, cycle 4 and subsequent cycles Follow-up Not applicable From day -14 to day 0 Cycle 1, day 1 Cycle 1, day 2 Cycle 1, day 3 Cycle 1, day 8 Cycle 2
1st day Cycle 3 ^b , day 1 Cycle 4 ^c
1st day Other EOT ^d Survival ^e Week 0 Week 1 Week 1 Week 1 Week 2 Week 3 Week ≥ 4 Informed consent before screening ^f X IHC analysis of FGFR2b expression X Sample for analysis of blood-based biopsy (coDNA) ^Xg X ^h X ^h X ^h X ^h X ^h Informed consent ⁱ X Consideration/confirmation of acceptance criteria X X Medical/cancer and drug history X X Taking tumor tissue ^j X Demographics/characteristics at baseline X Physical examination ^{k, l} X X X X X X X General condition index according to ECOG X ^Xm X Patient Evaluation Results (EQ-5D-5L and EORTC QLQ-C30) ⁿ X X ^k X ^k Vital signs ^o X X X X X X X X X 12 lead ECG ^p X X ^q X Comprehensive ophthalmological examination X X ^o X ^q X Slit lamp study ^{s Xs Xs} X Collection of laboratory samples for clinical safety analysis ^t X X X X X X X X Pregnancy test ^u X X X X Urinalysis ^v X X X X ^q X X-ray/tumor scan ^w X X ^x X ^x X ^x X ^y Randomization ^z X Survival score X Fresh tissue biopsy ^aa X X ^aa X ^aa Taking samples for immunogenicity analysis ^bb X ^{Xbb Xbb} X Sample collection for FCGR ^cc polymorphism analysis X Hair follicle samples ^dd X ^Xbb X Samples for PK analysis ^{Xee Xee Xee Xee Xee Xee Xee Xee} Biomarker Samples ^{Xff Xff Xff Xff Xff} Open introduction of antibodies to FGFR2-IIIb ^{Xgg Xgg Xgg Xgg} Introduction ^{Xhh Xii Xii Xii} X X X Introduction of masked antibodies to FGFR2-IIIb/placebo X ^jj X ^jj X ^jj X ^{jj Adverse} events X X------------------------------------------------- ------------------ X Concomitant drug therapy X------------------------------------------------- -------------------- X

a Unless otherwise specified, the procedure must be completed within ± 72 hours of the scheduled time point and must be synchronized with the day of study treatment administration. b: And subsequent odd cycles from cycle 3, unless otherwise noted. c And subsequent even cycles from cycle 4, unless otherwise noted. d End-of-treatment (EOT) evaluations should be performed 28 (± 3) days after the last study treatment administration e Patients in both Part 1 and Part 2 will undergo an extended period of follow-up for survival through clinic or telephone visits approximately every 3 months ± 28 days after the EOT visit, up to 24 months after the last patient entered the study. or until death, loss to follow-up, withdrawal of consent, or termination of the study by the sponsor (whichever comes first). f FIS before screening period g Sample for Blood Based Biopsy Analysis (cDNA) before the Screening Period for Part 2 only. Additional blood based biopsy samples (cDNA) are described in footnote h. h Samples for blood-based biopsy analysis (cDNA): PART 1: Samples for blood-based biopsy analysis (cDNA) will be collected prior to the first dose of study drug (cycle 1 day 1) and analyzed retrospectively for FGFR2 amplification. PART 2: Blood samples for ctDNA evaluation will be analyzed prospectively for FGFR2 amplification. In addition, blood-based biopsy (cDNA) analyzes will be performed longitudinally every 6 weeks from the first dose for 24 weeks and then approximately every 12 weeks thereafter and analyzed retrospectively for FGFR2 amplification. A sample will also be collected during the EOT visit from all Part 2 patients. i Written, signed informed consent must be obtained prior to any study-specific procedures. The most recent IRB/EC approved version of the FIS must be signed. j Tumor tissue from archival or recent acquisition (if available/acceptable) is required in Part 1 and Part 2. Refer to laboratory manual for sample handling instructions. k A complete physical examination and height measurement will only be performed at the time of screening. Thereafter, limited physical examinations, including examination of the oropharynx, should be performed. l After Cycle 1, the PI dose will only be recalculated at each infusion visit if weight has changed by >10% from Cycle 1, Day 1. m The ECOG General Health Score will be assessed on Cycle 3 Day 1 and on Day 1 of each subsequent cycle (odd cycles) prior to the EOT visit. n EQ-5D-5L and EORTC QLQ-C30 will be administered prior to dosing on Cycle 1, Day 1, Cycle 4, Day 1, Cycle 7, Day 1, Cycle 10, Day 1, Cycle 13, Day 1, and then every 12 weeks. o Measurement of vital signs (blood pressure, pulse, respiration and body temperature) should be measured on day 1 of cycle 1 at the following time points: before the dose, and also after 0.5, 1, 2 and 4 hours from the start of the infusion of antibodies to FGFR2-IIIb in Part 1 or masked PI infusion in Part 2. On subsequent days of dosing, before dosing and 0.5, 1 and 2 hours after the start of anti-FGFR2-IIIb infusion in Part 1 or masked PI infusion in Part 2 . p The patient must rest for 5 minutes before check-in. q Anytime if clinically indicated. r Comprehensive ophthalmic examinations (done only at Screening, before cycle 3 day 1 and at EOT visit) include fundoscopy and slit lamp examination, optical coherence tomography (OCT), visual acuity, fluorescein staining form completion, intraocular pressure and review of ocular/visual symptoms. A comprehensive eye examination will be repeated at any time if patients report changes in visual acuity or symptoms of visual impairment. s Slit lamp studies without OCT for patients in Part 1 and for patients in Part 2 randomized to receive antibodies to FGFR2-IIIb and FOLFOX 6; every 6 weeks after cycle 2, day 1 (until cycle 3, day 15, cycle 5, day 1 and cycle 6, day 15), and then every 12 weeks after cycle 6, day 15. Continue every 6 to 8 weeks if the patient has any persistent corneal disease. t Blood tests (assessed by local laboratories) are listed in Appendix 2. Results of haematological and biochemical blood tests must be obtained within 72 hours of administration of study drug on C1D1 to confirm eligibility. On dosing days, haematological and biochemical results should be available for 72 hours prior to dosing. Samples for coagulation analysis should be obtained at baseline, in cycles 1 through 4, and at any time when clinically indicated (eg, patients on anticoagulant therapy requiring close monitoring). u Serum ß-hCG analysis (assessed by local labs) will only be performed on women of childbearing potential ≤72 hours prior to cycle day 1 and at the EOT visit. On odd-numbered cycle dosing days (every second cycle), urinalysis results for pregnancy should be available within 72 hours prior to dosing. v Includes test strips for protein, glucose, blood, pH and ketones. If there is an abnormality in the analysis with the test strip, then a microscopic examination should be performed to assess the abnormalities. w Evaluation of tumors should consist of clinical examination and appropriate imaging modalities (preferably computed tomography with appropriate slice thickness according to RECIST); other evaluations (MRI, radiography, PET and ultrasound) may be performed if necessary. The same methods that were used to detect lesions at baseline should be used to track the same lesions throughout the clinical trial. Tumor screening scans should be performed within 2 weeks of starting treatment on day 1. x Tumor scans should be performed at screening (within 2 weeks of Cycle 1 Day 1 in Parts 1 and 2) and within 7 days prior to Cycle 1 Day 4, Cycle 1 Day 7, Cycle 1 Day 10, Cycle 1 Day 13, and then approximately every 12 weeks. If CR or PR is noted, a confirmatory scan should be performed 4 to 6 weeks later. Upon discontinuation of investigational treatment for reasons other than progression or withdrawal of consent, tumor evaluations will continue until the patient is started on additional cancer therapy or until progression occurs. y This tumor scan may be omitted if the last scan was performed less than 6 weeks prior to the EOT visit or if tumor progression was previously determined. z Part 2 only aa A fresh biopsy of the primary tumor or metastatic site is mandatory, to the extent possible, at screening [at least 24 hours prior to dosing] and during treatment within 7 days prior to day 1 of cycle 3 [and at least 24 hours pre-dose] in about 30 patients randomized to Part 2. (For patients who had a biopsy 12 weeks prior to enrollment, this sample may qualify for a new pre-treatment biopsy provided an adequate sample for PD analysis (one paraffin block) is available. or approximately 10 slides.) After consultation with the sponsor, patients with a documented response may have another biopsy within 28 (± 7) days of tumor assessment and/or patients with progression may have another biopsy at the time of EOT visit Biopsies after confirmation of response and after confirmation of progression are optional. bb Blood samples to determine the level of antibodies to FGFR2-IIIb. See Annex 3 for collection times. cc Sample for analysis on FCGR polymorphism. See Annex 3 for collection times. dd In Part 1 only, scalp or brow hair follicle samples (approximately 10, if any) will be collected prior to dosing on Cycle Day 1, Cycle Day 1, and Cycle Day 1 5, and at the EOT visit in all patients, from which sampling is possible. ee Blood samples for PK analysis. See Annex 3 for collection times. ff Blood samples for analysis of search biomarkers (parts 1 and 2). See Annex 3 for collection times. gg The unmasked anti-FGFR2-IIIb antibody will only be administered to patients included in Part 1. hh In Part 1, patients may start mFOLFOX6 chemotherapy prior to study entry and must be a candidate for at least 2 cycles of mFOLFOX6 chemotherapy to be eligible. In Part 2, patients must complete 2 cycles of mFOLFOX6 chemotherapy prior to randomization. ii FOLFOX is administered as a 46-hour continuous infusion. jj A masked PI (anti-FGFR2-IIIb antibody/placebo) will only be administered to patients randomized to Part 2. k.k. The collection of AEs starts after signing the FIS for screening. Events reported prior to the first infusion in a study will be considered pre-treatment events and reported on the eCRF case history page unless they are directly associated with a study-related procedure. The registration and reporting of adverse events will continue until the end of the EOT visit or until 28 days after the last dose of study drug.

Appendix 2: Laboratory Assessments

The following laboratory parameters will be determined in accordance with the Grading Schedule:

Hematology:
Complete blood count (CBC) with leukocyte formula:
leukocytes (WBC) platelets
ANC hemoglobin
neutrophils (%) hematocrit
eosinophils (%) erythrocytes (RBC)
basophils (%) erythrocyte indices:
lymphocytes (%) mean corpuscular volume (MCV)
monocytes (%) hemoglobin content in one erythrocyte (MCH)
mean erythrocyte hemoglobin concentration (MCHC) Analysis of urine:
Test strip (appearance, color, pH, specific gravity, ketones, protein, glucose, bilirubin, nitrite, urobilinogen and occult blood)
If the dipstick test is positive (2+ or higher) for blood or protein, perform microscopic examination. Biochemical analysis:
Albumin globulin
alkaline phosphatase glucose
ALT (SGPT) lactate dehydrogenase (LDH)
AST (SGOT) phosphate
blood urea nitrogen (BUN) potassium
sodium calcium
chloride total bilirubin
carbon dioxide (CO ₂ [bicarbonate]) total cholesterol
total protein creatinine
direct bilirubin uric acid

Appendix 3: Flow Chart for Collecting Blood Samples for PK, Immunogenicity, and Pharmacodynamic Analysis for Part 2

Research cycle Research days Moment of time sample type Cycle 1 Day 1 (first dose) ≤4 hours before infusion Antibodies to FGFR2-IIIb FC (serum) ADA (serum) Hair follicle (if present) Blood based biomarker (optional; whole blood) FCGR polymorphism (optional; whole blood) Blood based biopsy (cDNA) 5 minutes after completion of infusion Antibodies to FGFR2-IIIb FC (serum) 1 hour after completion of infusion (± 5 minutes) Antibodies to FGFR2-IIIb FC (serum) 4 hours after completion of infusion (± 5 minutes) Antibodies to FGFR2-IIIb FC (serum) Day 8 168 hours after completion of infusion (± 2 minutes) Antibodies to FGFR2-IIIb FC (serum) Day 15 (second dose) ≤4 hours before infusion Antibodies to FGFR2-IIIb FC (serum) 5 minutes after completion of infusion Antibodies to FGFR2-IIIb FC (serum) Cycle 2 to Cycle 5 Day 1 (first dose) ≤ 4 hours before infusion Antibodies to FGFR2-IIIb FC (serum) ADA (serum) Hair follicle in cycles 2 and 3 only (if present) Blood-based biomarker in cycle 4 only (optional; whole blood) 5 minutes after completion of infusion Antibodies to FGFR2-IIIb FC (serum) Day 15 (second dose) ≤ 4 hours before infusion Blood-based biomarker in cycles 2 and 5 only (optional; whole blood) Cycle 7 and subsequent cycles Day 1 (first dose) ≤ 4 hours before infusion FC antibodies to FGFR2-IIIb only in odd cycles (serum) ADA only in odd cycles (serum) Blood-based biomarker at cycle 7 and every 12 weeks thereafter (optional; whole blood) 5 minutes after completion of infusion FC antibodies to FGFR2-IIIb only in odd cycles (serum) End of treatment
Follow-up Date of visit During the visit Antibodies to FGFR2-IIIb FC (serum) ADA (serum) Hair follicle (if present) Blood based biomarker (optional; whole blood)

Annex 4: General condition indicator according to ECOG

Degree Criteria for the indicator of general condition 0 Fully active, able to perform all activities as before the disease without limitation. 1 Limited in activity to do physically hard work, but can do light sedentary work (light housework, office work). 2 He is being treated as an outpatient and is capable of self-care, but is unable to do any work. He spends more than 50% of his waking time actively - in an upright position. 3 Capable of only limited self-care, spends more than 50% of his waking time in a chair or bed. 4 Completely disabled. Completely incapable of self-care. Completely confined to bed or chair.

Example 2 Phase 1/3 Study of Anti-FGFR2-IIIb Antibody in Combination with Modified FOLFOX6 in Patients with Previously Untreated Advanced Gastric or Gastroesophageal Cancer

Summary of the content of the protocol

[00420] This study is a variation of the study described in Example 1 and is a multicenter study to evaluate the safety, tolerability, efficacy, PK and PD of an anti-FGFR2-IIIb antibody when administered in combination with mFOLFOX6. The study will include an open-label, lead-in phase to assess safety in patients with gastrointestinal (non-FGFR2-selective) tumors, followed by a randomized, open-label phase 3 in patients with FGFR2-selective gastric cancer (determined by prospective IHC analysis of FGFR2b overexpression and /or a ctDNA blood test showing amplification of the FGFR2 gene). After the initial screening period, patients will be treated with the mFOLFOX6 regimen in combination with anti-FGFR2-IIIb antibodies or mFOLFOX6 alone in two-week cycles.

Phase 1: Introductory phase to evaluate safety with dose escalation

[00421] Phase 1 is an open dose escalation study of anti-FGFR2-IIIb antibody in combination with mFOLFOX6. Eligible patients will need to have unresectable, locally advanced, or metastatic ECT cancer of any type and must be candidates for at least 2 doses of mFOLFOX6 chemotherapy. FGFR2 status is not a requirement for registration. FGFR2 status will be checked retrospectively by IHC (if tissue is available) and a sample will be obtained for analysis of ctDNA in the blood.

[00422] Phase 1 consists of at least two dosing cohorts of anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 to determine the RD of anti-FGFR2-IIIb antibodies to be administered in combination with mFOLFOX6 in phase 3. Patients may or may not have started or previously received mFOLFOX6 chemotherapy. There is no upper limit on the number of previous doses of mFOLFOX6 that patients may have received.

[00423] Each registered patient will be observed for 28 days (ESWL period) starting on the first day (cycle 1, day 1 [study day 1]) of anti-FGFR2-IIIb antibody treatment to assess safety, PK, and the occurrence of dose-limiting toxicity. Patient cohorts will be treated with escalating doses of anti-FGFR2-IIIb antibodies in combination with a standard dose of mFOLFOX6 chemotherapy in 2-week cycles.

Introduction of antibodies to FGFR2-IIIb

[00424] Anti-FGFR2-IIIb antibodies are administered intravenously every 2 weeks on day 1 of each cycle (2 weeks=1 cycle) and prior to mFOLFOX6 chemotherapy. Patients treated in cohort 2 will receive only one additional dose of anti-FGFR2-IIIb antibody on day 8 of cycle 1 (mFOLFOX6 will not be administered on that day). Anti-FGFR2-IIIb antibodies will be administered as an intravenous infusion over approximately 30 minutes via a peripheral vein or central venous catheter. An IV kit for infusion of anti-FGFR2-IIIb antibodies should contain a 0.22 µm inline filter or a 0.22 µm syringe filter.

Introduction of mFOLFOX6

[00425] Administration of mFOLFOX6 chemotherapy also begins on cycle day 1 (study day 1) of each treatment cycle 30 minutes after the end of the anti-FGFR2-IIIb antibody infusion. mFOLFOX6 will be administered every 2 weeks as follows: - Day 1: Oxaliplatin 85 mg/m ² IV infusion over 120 minutes, - Day 1: Leucovorin 400 mg/m ² IV infusion over 120 minutes may be administered simultaneously with oxaliplatin using a Y-coupler, if not using a Y-coupler, administer sequentially - Day 1: Immediately after oxaliplatin and leucovorin, 5 FU 400 mg/m ² by bolus injection over approximately 5 minutes - Day 1: Immediately after a bolus injection of 5-FU, 5-FU 2400 mg/m ² as a continuous IV infusion for 46 hours.

[00426] After the 28-day period of ESWL, patients may receive doses or receive reduced doses of mFOLFOX6 or anti-FGFR2-IIIb antibodies based on toxicity analysis. Premedication may be used at the investigator's discretion in accordance with local standard of care.

Phase 1 cohorts

[00427] In phase 1, the first anti-FGFR2-IIIb antibody dosing cohort to be analyzed is 6 mg/kg. Expected dose levels: - Cohort 1: 6 mg/kg anti-FGFR2-IIIb every 2 weeks; - Cohort 2: 15 mg/kg anti-FGFR2-IIIb every 2 weeks; 1 dose of 7.5 mg/kg on day 8 (cycle 1 only); - Cohort 3 (if needed): 15 mg/kg anti-FGFR2-IIIb every 2 weeks; - Cohort 4 (if required): Dose level lower than in cohort 3 but higher than in cohort 1 to achieve tolerability with optimal target exposure.

[00428] If the first cohort at 6 mg/kg eliminates the 28-day period of DLT, the second cohort dosing at 15 mg/kg every 2 weeks with a dose of 7.5 mg/kg on day 8 (cycle 1 only) will be tested in design 6 and 6 patients will be included. Dose escalation decisions will be based on evaluation of EBRT, overall safety and tolerability. Dose escalation decisions will be made after the last patient included in each cohort completes the 28-day period of ESWL (completion of 2 cycles of anti-FGFR2-IIIb and mFOLFOX6 antibody treatment). Dose escalation decisions will be agreed by the Cohort Review Review Committee (CRC), which includes the sponsor and investigators. If ≥ 2 DLTs are seen in cohort 2, the dose level between cohorts 1 and 2 can be assessed (cohort 3) in design 6 (15 mg/kg every 2 weeks). If ≥ 2 EBRTs occur in cohort 3, a dose level lower than in cohort 3 but higher than in cohort 1 can be assessed (cohort 4) in design 6. EBRT is defined as any of the following events that the investigator considers relevant to the introduction of antibodies to FGFR2-IIIb.

ANC <0.5 × 10 ⁹ /L >5 days or febrile neutropenia (i.e. ANC <1.0 × 10 ⁹ /L with one case of fever >38.3°C or fever >38°C during over 1 hour). The use of G-CSF is permitted in accordance with the standards of the institution

Platelets <25 × 10 ⁹ /L or platelets <50 × 10 ⁹ /L with bleeding requiring medical attention

Prolonged thrombocytopenia (>3 days) <50 × 10 ⁹ /l platelets

Grade 4 anemia (i.e. life-threatening consequences; urgent intervention indicated)

Any grade 2-3 ophthalmic AE that does not resolve within 7 days

Ophthalmic AE grade 4

AST/ALT > 3x ULN and concomitant total bilirubin >2x ULN not associated with liver cancer

Any non-hematologic AE grade 3 or higher (except nausea, vomiting, and diarrhea).

Grade 3 nausea, vomiting, or diarrhea that does not resolve with maintenance therapy within 72 hours.

Grade 3 laboratory findings that are of no clinical significance as agreed between investigator and sponsor unless resolved within 72 hours.

Nausea, vomiting, or grade 4 diarrhea

Any deviation from the norm in laboratory parameters of the 4th degree.

[00429] The following algorithm, presented in Table 6 below, will be used to decide whether to increase the dose:

Table 6: Dose escalation algorithm

Number of patients with EBRT Action 0/3 Open next cohort 1/3 Enroll 3 more patients in the same cohort ≥ 2/3 Stop dialing. If cohort 1, then the study will be stopped. 1/6 Open next cohort ≥ 2/6 Stop registration at this level. If cohort is 1, the study will end. If there are 2 or 3 in cohort, then cohort 3 or 4 will open respectively, and 6 patients will be included.

[00430] Anti-FGFR2-IIIb RD for phase 3 will be determined by CRC based on assessment of overall safety, tolerability and PK and will not exceed 15 mg/kg, will be administered intravenously every 2 weeks with 1 dose of 7.5 mg/kg for only Day 8 of Cycle 1. In determining the RD, the CRC will take into account toxicity observed during the ESWL evaluation period, any toxicity observed after the ESWL evaluation period, and dose reduction and discontinuation of mFOLFOX6 or anti-FGFR2-IIIb antibodies due to toxicity that does not match. DLT criteria. The RD of anti-FGFR2-IIIb antibodies selected based on the data set will be the dose that is not expected to result in a decrease in the intensity of mFOLFOX6 treatment to be administered. Therefore, the RD may or may not coincide with the determined maximum tolerated dose (MTD). For example, if the MTD is not achieved, or if data from subsequent treatment cycles from phase 1 provide additional insight into the safety profile, then the RD may be different from, but not higher than, the MTD.

[00431] MTD is defined as the maximum dose at which <33% of patients experience DLT (dose-limiting toxicity) during the period of DLT. If ESWL occurs in 1 of 3 patients in cohort 1, then 3 more patients will be included at the same dose level. Dose escalation may continue until 2 out of 3-6 patients treated at the dose level experience DLT (the dose level should not exceed the highest dose level tolerated in phase 1). Then the next lower dose will be considered the MTD.

Study design

[00432] Once enrollment begins in Cohort 2 (15 mg/kg every 2 weeks cohort with 1 dose of 7.5 mg/kg on Day 8 [Cycle 1 only]), 6 patients will be enrolled in a study to study safety and efficacy . The total enrollment for Phase 1 will be approximately 9 to 21 patients.

[00433] Any patient who does not receive the full number of doses of anti-FGFR2-IIIb antibodies as defined by cohort and 2 full doses of mFOLFOX6 during the EBRT period for a reason that is not EBRT or an AE associated with the introduction of antibodies to FGFR2-IIIb , will be considered non-evaluable and the patient will be replaced. The replacement patient may continue to participate in the study at the discretion of the investigator and after discussion with the sponsor. During the 28-day period of EBRT, no additional doses of anti-FGFR2-IIIb antibodies or more than 2 doses of mFOLFOX6 should be administered. It is not necessary to synchronize the doses of anti-FGFR2-IIIb and mFOLFOX6 antibodies on day 1 of cycle 2. For example, if mFOLFOX6 administration is delayed due to an AE that is considered to be related only to mFOLFOX6 and not to anti-FGFR2-IIIb, anti-FGFR2-IIIb should be administer as scheduled for cycles 1 and 2, regardless of delays in the mFOLFOX6 dosing schedule.

[00434] At the end of the EBRT period, patients may continue to receive anti-FGFR2-IIIb antibody in combination with mFOLFOX6 at the discretion of the investigator. Additional treatments may be given every 2 weeks (cycle 1) until radiographic or clinical evidence of disease progression as assessed by the investigator, unacceptable toxicity occurs, or until the patient meets any of the other exclusion criteria specified in the protocol.

[00435] If a mFOLFOX6 cycle is delayed more than 2 weeks due to chemotherapy-related toxicity during the first 3 treatment cycles (42 days), anti-FGFR2-IIIb antibody should be administered on schedule (± 3 days). After the first 3 cycles, administration of the anti-FGFR2-IIIb antibody may be delayed up to ± 7 days to synchronize with the administered mFOLFOX6. There is no mandatory maximum dose of anti-FGFR2-IIIb or mFOLFOX6 antibody. Continued introduction of the mFOLFOX6 regimen after the EBRT period will be conducted according to the following schedule:

The initial dose of mFOLFOX6 includes 85 mg/m ² oxaliplatin, 400 mg/m ² calcium folinate (folinic acid), 400 mg/m ² 5-FU bolus, and 2400 mg/m ² fluorouracil infusion over 46 hours.

The mFOLFOX6 regimen will be administered every 2 weeks (± 3 days) until confirmation of disease progression as assessed by the investigator via radiography (Phase 3 only) or clinical disease progression (Phase 1 only), unacceptable toxicity occurs, or until the patient complies with any of the others specified in the protocol. exclusion criteria.

Day 1: Oxaliplatin 85 mg/m ² IV infusion over 120 minutes

Day 1: Leucovorin IV infusion 400 mg/m ² over 120 minutes may be administered simultaneously with oxaliplatin using a Y-piece, if a Y-piece is not used, administer sequentially

Day 1: Immediately after oxaliplatin and leucovorin, 5 FU 400 mg/m ² by bolus injection over approximately 5 minutes

Day 1: Immediately after a bolus injection of 5-FU, 5-FU 2400 mg/m ² as a continuous IV infusion for 46 hours.

[00436] Any changes to the current administration of mFOLFOX6 may be made in accordance with the following guidelines:

If the change in body weight is at least 10%, doses should be recalculated.

Advise patients to avoid exposure to cold weather during and for approximately 72 hours after each infusion.

Correct hypokalemia and hypomagnesaemia before initiating oxaliplatin administration.

Severe diarrhoea, mucositis, and myelosuppression following 5-FU administration should warrant evaluation for dihydropyrimidine dehydrogenase deficiency.

The dose of leucovorin is administered as a d, l-racemic mixture. Use half the dose for LEVO-leucovorin (l-leucovorin)

In the event that oxaliplatin is discontinued for any reason prior to disease progression, 5-FU/leucovorin therapy may be continued every 2 weeks until disease progression, unacceptable toxicity, or other reason to terminate the study. If 5FU/leucovorin therapy is discontinued, then the administration of oxaliplatin should be discontinued.

[00437] Some dose adjustments for mFOLFOX6 toxicity are shown in Table 7.

Table 7: Dose reduction and deferral for mFOLFOX6 chemotherapy

Toxicity Degree Oxaliplatin 5-FU/leucovorin Neurotoxicity Persistent neurotoxicity (≥1 cycle) grade 2 Reduction from 85 mg/m ² to 65 mg/m ² * Without changes Temporary neurotoxicity (>7 days and ≤14 days) grade 3 Reduction from 85 mg/m ² to 65 mg/m ² * Without changes Persistent neurotoxicity (≥1 cycle) ≥ Grade 3 or any Grade 4 neurotoxicity Cancel Without changes Gastrointestinal ≥3rd degree (after prophylaxis) Suspend until toxicity ≤ Grade 1, reduce from 85 mg/m ² to 65 mg/m ² * Suspend until toxicity ≤ Grade 1, reduce by 20%* Hematological Platelet elevation ≥3rd grade Suspend until platelet count is ≥75,000, reduce from 85 mg/m ² to 65 mg/m ² * Reduce by 20%* Neutropenia ≥3rd degree Suspend until ANC ≥1500, then reduce from 85 mg/m ² to 65 mg/m ² * Reduce by 20%* Cutaneous Hand and foot syndrome ≥3rd degree Suspend until 5-FU administration resumes, then no change Suspend to ≤1st degree, then reduce by 20%* Other ≥3rd degree Suspend to ≤1st degree, then reduce from 85 mg/m ² to 65 mg/m ² * Suspend to ≤1st degree, then reduce by 20%* Pharyngolaryngeal dysesthesia Any Stop the infusion, then consider extending the duration of the infusion to 6 hours Without changes Pneumonitis Any Suspend, conduct an examination; permanently cancel if confirmed Liver failure Bilirubin 1-2 × VPN Without changes No change, consider 20% reduction* Bilirubin >2-4 x ULN and/or AST/ALT 2-4 x ULN Without changes No change, consider 20% reduction Bilirubin >4 x ULN and/or AST/ALT >4 x ULN Cancel Cancel Renal failure (creatinine clearance) >50 ml/min Without changes Without changes 30 to <50 ml/min No change, consider lowering to 65 mg/m ² * Without changes <30 ml/min Cancel Reduce dose by 20%*

*When toxicity of the same degree recurs after dose reduction; consider permanent cancellation. Note that if 5-FU is permanently discontinued, oxaliplatin and leucovorin should also be permanently discontinued. (Adapted from Cheeseman 2002, Hochster 2008, Teva Parenteral Medicines Inc. 2016, Teva Parenteral Medicines Inc. 2014, Teva Pharmaceuticals USA 2012.)

[00438] In the Phase 1 portion of the study, if anti-FGFR2-IIIb antibody is permanently discontinued for any reason, the patient will undergo an end-of-treatment (EOT) visit as part of the follow-up period approximately 28 days after the last dose of anti-FGFR2-IIIb antibody. There will be no further follow-up for these patients, and the end-of-treatment visit with anti-FGFR2-IIIb antibodies within the follow-up period marks the end of the study. If mFOLFOX6 is discontinued for any reason other than progression as judged by the investigator or any of the other withdrawal criteria specified in the protocol, anti-FGFR2-IIIb administration may be continued as monotherapy at the discretion of the investigator.

Randomized open-ended phase 3

[00439] Enrollment in Phase 3 will begin when the CRC determines an RD for an anti-FGFR2-IIIb antibody that does not exceed the highest dose level evaluated and tolerated in Phase 1. Patients may enroll in either Phase 1 or Phase 3, but may not participate in both phases of the study. Opening part of the Phase 3 study to recruitment will be at the discretion of the sponsor.

[00440] Eligibility criteria require patients to have unresectable locally advanced or metastatic gastric cancer, be candidates for mFOLFOX6 chemotherapy as standard first-line therapy, and have a tumor that is FGFR2-positive on centralized IHC and/or analysis of ctDNA in blood. The Informed Consent Form (FIS) prior to screening must be signed by patients prior to providing tissue (archived or fresh) and a blood sample for FGFR2 analysis. Since it may take approximately 2 weeks to receive results from a centralized FGFR2 test, patients are allowed to receive 1 dose of mFOLFOX6 during this interim period (pre-screening period) at the discretion of the investigator. This 1 dose of chemotherapy is not required for the study and is not considered part of this clinical study.

[00441] Patients whose tumors test positive for FGFR2b by IHC and/or test positive for FGFR2 gene amplification by blood ctDNA analysis may consent to full participation in the study (sign FIS for the full study) and enter the screening period . The time between signing the FIS for a full study and registration in the study is considered the screening period (up to 21 days). During the screening period, the patient will undergo the screening procedures specified in the protocol to ensure that all eligibility criteria are met.

[00442] Part of the Phase 3 study is a randomized, open-label study and includes 548 patients with FGFR2-selective gastric cancer randomized in a 1:1 ratio to receive an RD of an anti-FGFR2-IIIb antibody in combination with mFOLFOX6 versus mFOLFOX6 to evaluate the effectiveness of the combination. Patients should receive their first dose of study treatment within 3 days of randomization. Treatment groups consist of: - Group 1: administration of anti-FGFR2-IIIb antibody in combination with mFOLFOX6 every 2 weeks, or - Group 2: administration of mFOLFOX6 every 2 weeks.

[00443] Withdrawal of any component of investigational treatment (mFOLFOX6, mFOLFOX6 component, or anti-FGFR2-IIIb antibody) for any reason other than disease progression does not require withdrawal of other components. An exception is the withdrawal of 5-FU for any reason that requires the withdrawal of oxaliplatin and leucovorin. Continued administration of the mFOLFOX6 regimen can be provided as discussed above.

[00444] For the first 3 treatment cycles, anti-FGFR2-IIIb antibody should be administered on a schedule (± 3 days) regardless of delays in mFOLFOX6 treatment. In case of delaying the administration of mFOLFOX6 after the first 3 cycles of anti-FGFR2-IIIb antibody, there may be a delay in the administration of anti-FGFR2-IIIb antibody up to 7 days to synchronize with the introduction of mFOLFOX6. However, the timing of the introduction of antibodies to FGFR2-IIIb and mFOLFOX6 is not a mandatory protocol requirement. If after 7 days the patient is still unable to receive mFOLFOX6, PPI should be continued as monotherapy every 2 weeks (± 3 days).

[00445] Patients who discontinue all study treatment (all anti-FGFR2-IIIb and mFOLFOX6 antibody components) for any reason other than withdrawal of consent will undergo an EOT follow-up safety evaluation visit approximately 28 days after the last dose of the last an administered treatment component (oxaliplatin, leucovorin, 5-FU, or an anti-FGFR2-IIIb antibody).

[00446] However, patients who discontinue investigational treatment (anti-FGFR2-IIIb and/or mFOLFOX6 antibody) for reasons other than disease progression or withdrawal of consent will continue to undergo tumor evaluations according to the protocol schedule until radiologically confirmed progression or onset additional anti-cancer therapy, after which they had to undergo long-term follow-up to assess survival.

[00447] Long-term follow-up to assess survival will be completed through a clinic visit, phone call, or use of patient registries (in accordance with national and applicable data protection laws) approximately every 3 months (± 1 month) after the EOT visit, up to 24 months after the last patient was included in the study, or until death, loss to follow-up, withdrawal of consent, or termination of the study by the sponsor (whichever comes first).

Inclusion Criteria for Phase 1 and Phase 3

[00448] Patients enrolled in Part 1 or Part 3 of the study must also meet all of the following inclusion criteria:

Unresectable, locally advanced or metastatic disease

Understand and sign an Informed Consent Form (FIS) endorsed by an Institutional Review Board (IRB)/Independent Ethics Committee (IEC) prior to any evaluation conducted for a study

Life expectancy of at least 3 months, according to researcher

Eastern Cooperative Oncology Group (ECOG) General Condition Score 0 to 1

Age ≥18 years at the time of signing the FIS

Negative serum β-human chorionic gonadotropin (β-hCG) pregnancy test ≤96 hours prior to treatment (women of childbearing potential only) in cycle 1, day 1

For sexually active patients (women of childbearing potential and men), willingness to use 2 effective methods of contraception, of which 1 must be a barrier method (condom, diaphragm, or cervical cap/vaginal cap) within 6 months after the last dose of anti-FGFR2- antibody IIIb. Other effective forms of contraception include:

Permanent sterilization (hysterectomy and/or bilateral oophorectomy or bilateral tubal ligation or vasectomy) at least 6 months prior to screening

Women of childbearing potential who are on stable oral contraceptive therapy or who have had an intrauterine or implantable device for at least 90 days prior to study entry or abstain from sexual intercourse as a lifestyle

Adequate hematological and biological function, confirmed by the following laboratory parameters during 96 hours of cycle 1 day 1.

Bone marrow function

Absolute neutrophil count (ANC)≥1.5 × 10 ⁹ /l

Platelets ≥100 × 10 ⁹ /l

Hemoglobin ≥9 g/dl

liver function

Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) <3× upper limit of normal (ULN); in case of liver metastases, then <5 × TLN

Bilirubin <1.5 × ULN

Kidney function

Estimated creatinine clearance using the Cockcroft-Gault formula ≥50 ml/min.

Patients on full-dose anticoagulants should be on a stable dose of warfarin for 6 weeks prior to enrollment and have an international normalized ratio (INR) within the therapeutic range to treat the patient's condition or be on a stable dose of low molecular weight heparin.

Measurable or non-measurable disease

Patients enrolled in Part 1 of the study must also meet the following inclusion criteria:

Histologically or cytologically confirmed gastrointestinal malignancy for which the mFOLFOX6 regimen is considered an appropriate treatment (eg, gastric cancer, colorectal cancer, pancreatic adenocarcinoma)

Tumor tissue (if available) to determine FGFR2b overexpression by IHC.

The patient must be a candidate for at least 2 doses of mFOLFOX6 chemotherapy at the doses listed below and must meet the above toxicity guidelines:

The administration of mFOLFOX6 chemotherapy will begin on day 1 of cycle 1 (study day 1) of each treatment cycle 30 minutes after the end of the infusion. Anti-FGFR2-IIIb/mFOLFOX6 antibodies will be administered every 2 weeks as follows:

Day 1: Oxaliplatin 85 mg/m ² IV infusion over 120 minutes.

Day 1: Leucovorin IV infusion 400 mg/m ² over 120 minutes can be administered simultaneously with oxaliplatin using a Y-piece connector. If a Y-connector is not available, enter sequentially.

Day 1: Immediately after oxaliplatin and leucovorin, 5 FU 400 mg/m ² by bolus injection over approximately 5 minutes.

Day 1: Immediately after a bolus injection of 5-FU, 5-FU 2400 mg/m ² as a continuous IV infusion for 46 hours. After the first dose, patients may be subjected to dose reductions, delays may occur, or the drug may be discontinued on the basis of toxicity as recommended.

[00449] Patients enrolled in Part 3 of the study must also meet the following inclusion criteria:

Histologically confirmed adenocarcinoma of the stomach or gastroesophageal junction (defined as 5 cm proximally and distally from the GEP)

X-ray examination of the chest, abdomen, and pelvis (preferably computed tomography (CT), magnetic resonance imaging (MRI) is acceptable) taken within 28 days of C1D1

Tumor tissue for FGFR2b overexpression as determined by a centrally performed IHC study and/or FGFR2 gene amplification as determined by a centrally performed blood-based ctDNA analysis

The patient must be a candidate for mFOLFOX6 chemotherapy

No prior chemotherapy for metastatic or unresectable disease (with the exception of a maximum of 1 dose of mFOLFOX6 given while waiting for FGFR2 test results during the pre-screening period)

No prior platinum-based chemotherapy (except as noted in Inclusion Criteria #18)

If prior adjuvant or neoadjuvant therapy (chemotherapy and/or chemoradiotherapy) was performed, more than 6 months must elapse between the end of adjuvant therapy and recruitment

Exclusion Criteria for Phase 1 and Phase 3

[00450] Patients enrolled in phase 1 or phase 3 will be excluded if any of the following criteria apply:

Untreated or symptomatic central nervous system (CNS) metastases (CNS imaging studies not required). Patients with asymptomatic CNS metastases are eligible provided they have been clinically stable for at least 4 weeks and do not require intervention such as surgery, radiation, or any corticosteroid therapy to treat symptoms associated with CNS disease.

Weakened heart function or clinically significant heart disease, including any of the following:

Unstable angina ≤6 months prior to enrollment

Acute myocardial infarction ≤6 months prior to enrollment

Congestive heart failure, class II-IV, according to the functional classification of the New York Heart Association

Uncontrolled hypertension (defined as ≥ 160/90 despite optimal medical management)

Uncontrolled cardiac arrhythmia requiring antiarrhythmic therapy other than beta-blockers or digoxin

Active coronary artery disease

QTCF > 480

Peripheral sensory neuropathy grade 2 or higher according to ≥ Standard terminological criteria for adverse events (CTCAE)

Active infection requiring systemic treatment or any uncontrolled infection ≤14 days prior to registration

Confirmed human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS)-associated disease or history of confirmed or chronic hepatitis B or C infection

History of interstitial lung disease (eg, pneumonitis or pulmonary fibrosis)

Evidence or history of hemorrhagic diathesis or coagulopathy

Radiation therapy ≤28 prior to enrollment. Patients must recover from all acute toxic effects associated with radiotherapy. Radiopharmaceuticals (strontium, samarium) should not be used within 8 weeks after registration

Pretreatment with any selective inhibitor (eg, AZD4547, BGJ398, JNJ-42756493, BAY1179470) of the FGF-FGFR pathway

Current side effects from previous systemic treatment > NCI CTCAE grade 1 (excluding grade 2 alopecia)

Participation in another therapeutic clinical trial or receipt of any investigational drug within 28 days of registration or during that clinical trial

Corneal defects, corneal ulceration, keratitis, keratoconus, corneal transplantation, or other known history of corneal abnormalities that, in the opinion of the ophthalmologist, may pose an increased risk of developing a corneal ulcer

Known positive for HER2 (defined as positive IHC 3+ assay or IHC 2+ positive FISH).

Major surgery is not allowed ≤28 days prior to enrollment. Surgery requiring local/epidural anesthesia must be completed at least 72 hours before check-in. In all cases, the patient must be sufficiently recovered and stable before starting treatment.

Women who are pregnant or breastfeeding (if the patient does not wish to interrupt breastfeeding during study treatment and then resume 6 months after study termination); women of childbearing potential should not consider becoming pregnant during the study

Presence of any serious or unstable comorbid systemic disorder incompatible with clinical investigation (eg, substance abuse, psychiatric disorder, or uncontrolled intercurrent illness including arterial thrombosis and symptomatic pulmonary embolism)

The presence of any other condition that may increase the risk associated with participation in the study or may interfere with the interpretation of the results of the study and, in the opinion of the investigator, would make the patient ineligible for inclusion in the study

Known allergy or hypersensitivity to components of an anti-FGFR2-IIIb antibody formulation, including polysorbate, or to products containing platinum, 5-FU, or leucovorin

History of previous malignant neoplasm, except:

non-melanoma malignant neoplasm of the skin, for which radical treatment was carried out

cervical cancer in situ

ductal or lobular breast cancer in situ, for which radical treatment was performed and the patient is currently not receiving systemic therapy

solid tumor, which was radically treated more than 5 years ago without signs of recurrence.

[00451] No waiver of these inclusion or exclusion criteria will be granted.

Investigational treatment

[00452] In Phase 1, the anti-FGFR2-IIIb antibody will be supplied in a sterile reconstitution vial in an intravenous (IV) bag at the study site for approximately 30 minutes (± 10 minutes) every 2 weeks (± 3 days) until administration of chemotherapy according to the mFOLFOX6 scheme. Only patients treated in cohort 2 will receive 1 additional dose of anti-FGFR2-IIIb antibody on day 8 of cycle 1. Beginning with cycle 2, all patients will receive anti-FGFR2-IIIb antibody every 2 weeks on day 1 of each cycle until radiological or clinical evidence of disease progression as assessed by the investigator, the occurrence of unacceptable toxicity, or until the patient meets any of the other exclusion criteria specified in the protocol. The FP144 IV Infusion Set must contain a 0.22 µm inline filter or a 0.22 µm syringe filter.

[00453] In phase 3, the anti-FGFR2-IIIb antibody will be delivered and administered similarly to the anti-FGFR2-IIIb antibody in phase 1. Administration of the anti-FGFR2-IIIb antibody will continue until radiographic or clinical confirmation of disease progression as assessed by the investigator, the occurrence of unacceptable toxicity, or until the patient meets any of the other criteria specified in the protocol.

[00454] Oxaliplatin, 5-FU, and leucovorin (mFOLFOX6) will be administered at each study center (as described above) every 2 weeks (± 7 days).

Pharmacokinetic evaluations

[00455] Blood samples will be collected at specific time points to measure serum levels of anti-FGFR2-IIIb antibody in all enrolled patients in phase 1 and phase 3, respectively.

[00456] PK parameters will be assessed using non-compartmental analysis, although compartmental analysis may be used if necessary. Serum concentration versus time data from this clinical trial will be combined with data from other studies for a comprehensive population PK analysis and exposure-response relationship.

Immunogenicity scores

[00457] All registered patients in phase 1 and phase 3 will have blood samples taken for testing for antibodies to FGFR2-IIIb. Immunogenicity, defined as an immune response to an anti-FGFR2-IIIb antibody, will be assessed by measuring the total level of anti-FGFR2-IIIb antibodies in all patients. The immunogenicity test will consist of screening, confirmation and titration. Additional characterization of a confirmed anti-FGFR2-IIIb antibody response may be considered.

Efficiency mark

[00458] During Phase 3, evaluation of tumor response will be performed by the investigator in accordance with RECIST v.1.1 guidelines. Performance measures will include tumor evaluations consisting of clinical examination and appropriate imaging modalities, preferably CT scan of the chest, abdomen, and pelvis with appropriate slice thickness according to RECIST v1.1 guidelines, but MRI is also acceptable. Scans will be taken during the screening window (within 21 days of day 1 of cycle 1). A scan performed prior to screening as part of standard care performed no later than 28 days prior to enrollment is acceptable. Scans will be performed every 8 weeks (±7 days) from Day 1 of Cycle 1.

Safety ratings

[00459] Safety measures will include AEs, hematology, biochemistry, urinalysis, vital signs, body weight, use of concomitant medications/procedures, ECOG general status score, targeted physical examinations, ECG, and ophthalmological examinations as in phase 1 as well as phase 3.

Pharmacodynamic assessments

Phase I

[00460] PD assessments will be conducted at certain points in time. Tumor tissue submitted for FGFR2 status, if present, will be retrospectively analyzed for FGFR2b overexpression using IHC. Blood samples submitted for FGFR2 status assessment will be collected prior to the first dose of study treatment and analyzed retrospectively for FGFR2 gene amplification by blood ctDNA analysis. Blood samples for analysis of FGFR pathway exploratory biomarkers will be collected longitudinally.

Phase 3

[00461] Tumor tissue will be submitted for FGFR2 status assessment and will be prospectively analyzed for FGFR2b overexpression using IHC. Blood samples will be submitted for evaluation of FGFR2 status and will be prospectively analyzed for FGFR2 gene amplification using blood ctDNA analysis. Positive tissue or blood test results, but not both, must be available prior to enrollment.

[00462] The total number of participants scheduled for this study is approximately 569 patients. Approximately 9-21 patients being evaluated for any dose-limiting toxicity will be enrolled in Phase 1. In Phase 3, efficacy and tolerability will be assessed by enrolling approximately 548 patients with FGFR2-selective gastric cancer randomized in a 1:1 ratio to receive antibodies to FGFR2- IIIb in combination with mFOLFOX6 or mFOLFOX6 alone. Eligible patients will be categorized by geographic region (US and EU, Japan, Rest of Asia [including China], Rest of the World), prior treatment status ( de novo or adjuvant/neoadjuvant), and pre-registration single dose of mFOLFOX6 (yes or No).

[00463] In Phase 1, all analyzes will be descriptive and will be presented by dose group and in general as needed. Descriptive statistics will include number of observations, mean, standard deviation, median, range, and interquartile breadth for continuous variables, and number and percentage for categorical variables; 95% confidence intervals will be presented where appropriate. Additionally, the frequency of AEs leading to dose reduction or dose withdrawal will be tabulated and summarized. In phase 3, the primary efficacy analysis is a comparison of OS in patients treated with anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 or mFOLFOX6.

[00464] The primary endpoint, OS, is defined as the time from randomization to death from any cause. Secondary efficacy endpoints include PFS and ORR, where PFS is defined as the time from randomization to the date of radiological confirmation of disease progression based on investigator assessment (according to RECIST v.1.1) or death from any cause, whichever comes first, and ORR is defined as as the proportion of patients with baseline-measured disease with partial or complete response as determined by the investigator according to RECIST v.1.1.

[00465] This Phase 3 study is designed to evaluate the hazard ratio (HR) for overall survival (OS) for the combination of anti-FGFR2-IIIb antibody and mFOLFOX6 versus mFOLFOX6 alone. 374 primary death events can provide 80% power to determine an HR of 0.75 for OS using Cox regression analysis having a (one-tailed) false positive error rate of 2.5%. Assuming an exponential distribution of OS, this would correspond to a 33% increase in average OS from 10 to 13.3 months. Statistical significance for OS would occur at an estimated HR of 0.815, which is roughly equivalent to a 22.6% increase in median survival from 10 to 12.26 months.

[00466] Approximately 548 patients will be randomized (1:1) within 44 months of enrollment, followed by approximately 24 additional months of follow-up to achieve the target number of primary events.

[00467] First, the OS hypothesis will be tested. There will be 2 interim analyzes and a primary OS analysis, both of which will be event-based analyzes.

[00468] Two interim OS analyzes are scheduled; the first after 50% OS events (approximately 187 events) and the second after 75% OS events (approximately 281 events). The O'Brien-Fleming monitoring cut-off criterion will be used to maintain a false-positive error rate of 2.5%, and the application of the Lahn-DeMets modification will allow for flexibility in the number and timing of these interim analyses.

[00469] Primary analysis of OS will be performed using the in-treatment intent (ITT) population and will be performed using a stratified log-rank test. The stratification factors will be the same as for randomization schedule stratification as described in the Interactive System Allowing Phone Call and Internet Access (IXRS).

[00470] The median OS and the corresponding 95% confidence interval for each treatment group will be estimated using the Kaplan-Meier method. The hazard ratio (HR= λ _{anti-FGFR2-IIIB+mFOLFOX6} / λ _mFOLFOX6 )) will be estimated using a Cox regression model with treatment group as the single main effect and stratification using the same stratification factors as used for the stratified log-rank test . Unstratified HR will also be presented.

[00471] The analysis of PFS and ORR secondary endpoints will be conducted hierarchically if the analysis of the OS primary endpoint is statistically significant. Formal hypotheses regarding the impact on PFS and ORR will be tested hierarchically at the 0.05 level. The PFS will be checked first and if it is significant then the ORR will be checked. The Type I error rate, corrected for the effect of multiple comparisons on primary and secondary endpoint testing, will be controlled by this step-input testing procedure at a level of 0.05.

[00472] If OS testing is meaningful, we will test for progression-free survival (PFS), using a stratified log-rank test at the 0.05 level, based on all PFS events observed during OS analysis. Primary PFS analysis will be performed using a stratified log-rank test (two tailed). The stratification factors will be the same as for randomization schedule stratification as described in the Interactive System Allowing Phone Call and Internet Access (IXRS).

[00473] The median PFS and the corresponding 95% confidence interval for each treatment group will be estimated using the Kaplan-Meier method. HR will be estimated using a Cox regression model with treatment group as the single main effect and stratification using the same stratification factors used for the stratified log-rank test. Unstratified HR will also be presented. PFS analysis will be performed on the ITT population.

[00474] If testing for PFS is significant, then ORR analysis will be performed among patients with measurable disease at baseline. In the analysis of ORR, patients who do not have adequate post-baseline tumor scores will be counted as non-responders. A formal test of the ORR hypothesis will be performed using a stratified Cochran-Mantel-Haenszel test (two tailed) at the 0.05 level. The stratification factors will be the same as for randomization schedule stratification as described in IXRS.

[00475] Safety Analysis: All AEs will be coded using the Medical Dictionary for Regulatory Activities (MedDRA). The investigator will classify the severity of the AE using CTCAE v 4.03. An adverse event occurring during treatment (AEIE) is defined as any event with an onset date on or after the date of administration of the first dose of study treatment, or any event present before treatment that worsens after treatment. The summary tables will include only NJVL with the date of occurrence before the date of the last dose + 28 days.

[00476] Clinical laboratory data will be summarized by laboratory type. The number and percentage of patients who show abnormalities (i.e., values outside the normal ranges) and/or clinically significant abnormalities following study treatment administration will be reported for each clinical laboratory test score. For each clinical laboratory test score, descriptive statistics will be provided for baseline and all subsequent scheduled post-treatment visits. Changes from baseline to post-treatment visits will also be provided. Descriptive statistics on vital signs will also be provided in a similar manner. In addition, shift from baseline in CTCAE grade (where applicable) and high/low scores (in cases where CTCAE grades are not defined) will be similarly presented.

[00477] Phase I safety analyzes will be performed on patients included in the safety evaluation population. The frequency of SWL, the frequency of TEAE, abnormalities in clinical laboratory results (for example, a table of shifts), vital signs, corneal and retinal examination and ECG results will be tabulated and summarized by dose level. Additionally, the frequency of TEAE resulting in dosage reduction or dose withdrawal will be tabulated and summarized.

[00478] The phase 3 safety analysis will include all patients who receive any investigational treatment (anti-FGFR2-IIIb antibodies in combination with mFOLFOX6 or mFOLFOX6) during the entire study period and will provide any post-treatment safety information. TEAE incidence, clinical laboratory abnormalities, vital signs, corneal and retinal findings, and ECG findings will be tabulated and summarized by treatment group.

[00479] Individual and mean (± SD) serum anti-FGFR2-IIIb antibody concentration versus time data will be tabulated and plotted against dose level. PK parameters will be tabulated and summarized by dose level when relevant and applicable. The impact of immunogenicity on exposure to FGFR2-IIIb antibodies will be assessed, tabulated and summarized by dose level to the best of the data. An integrated population-based PK analysis and response-to-exposure assessment will be presented in a separate report.

[00480] A schematic representation of the studied cohorts is shown in FIG. 3.

Sequence table

[00481] The table below lists the specific sequences referenced in this document.

SEQ. ID. NO. Description Subsequence 1 Mature human FGFR2-IIIb N QHWSLIMES VVPSDKGNYT CVVENEYGSI NHTYHLDVVE RSPHRPILQA GLPANASTVV GGDVEFVCKV YSDAQPHIQW IKHVEKNGSK YGPDGLPYLK VLKHSGINSS NAEVLALFNV TEADAGEYIC KVSNYIGQAN QSAWLTVLPK QQAPGREKEI TASPDYLEIA IYCIGVFLIA CMVV TVILCR MKNTTKKPDF SSQPAVHKLT KRIPLRRQVT VSAESSSSMN SNTPLVRITT RLSSTADTPM LAGVSEYELP EDPKWEFPRD KLTLGKPLGE GCFGQVVMAE AVGIDKDKPK EAVTVAVKML KDDATEKDLS DLVSEMEMMK MIGKHKNIIN LLGACTQDGP LYVIVEYASK GNLREYLRAR RPPGMEYSYD INRVPEEQMT FKDLVSCTYQ LARGMEYLAS QKCIHRDLAA RNVLVTENNV MKIADFGLAR DINNIDYYKK TTNGRLPVKW MAPEALFDRV YTHQSDVWSF GVLMWEIFTL GGSPYPGIP V EELFKLLKEG HRMDKPANCT NELYMMMRDC WHAVPSQRPT FKQLVEDLDR ILTLTTNEEY LDLSQPLEQY SPSYPDTRSS CSSGDDSVFS PDPMPYEPCL PQYPHINGSV KT 2 Heavy chain anti-FGFR2b; Asn297 is bold and underlined QVQLVQSGAE VKKPGSSVKV SCKASGYIFT TYNVHWVRQA PGQGLEWIGS IYPDNGDTSY NQNFKGRATI TADKSTSTAY MELSSLRSED TAVYYCARGD FAYWGQGTLV TVSSASTKGP SVFPLAPSSK STSGGTAALG CLVKDYFPEP VTVSWNSGAL TSGVHTFPAV LQSSGLYSLS SV VTVPSSSL GTQTYICNVN HKPSNTKVDK RVEPKSCDKT HTCPPCPAPE LLGGPSVFLF PPKPKDTLMI SRTPEVTCVV VDVSHEDPEV KFNWYVDGVE VHNAKTKPRE EQY N STYRVV SVLTVLHQDW LNGKEYKCKV SNKALPAPIE KTISKAKGQP REPQVYTLPP SREEMTK NQV SLTCLVKGFY PSDIAVEWES NGQPENNYKT TPPVLDSDGS FFLYSKLTVD KSRWQQGNVF SCSVMHEALH NHYTQKSLSL SPGK 3 Anti-FGFR2b light chain STYS LSSTLT LSKADYEKHK VYACEVTHQG LSSPVTKSFN RGEC 4 Anti-FGFR2b heavy chain variable region QVQLVQSGAE VKKPGSSVKV SCKASGYIFT TYNVHWVRQA PGQGLEWIGS IYPDNGDTSY NQNFKGRATI TADKSTSTAY MELSSLRSED TAVYYCARGD FAYWGQGTLV TVSS 5 Anti-FGFR2b light chain variable region DIQMTQSPSS LSASVGDRVT ITCKASQGVS NDVAWYQQKP GKAPKLLIYS ASYRYTGVPS RFSGSGSGTD FTFTISSLQP EDIATYYCQQ HSTTPYTFGQ GTKLEIK 6 HVR1 heavy chain (HC) anti-FGFR2b TYNVH 7 HC HVR2 anti-FGFR2b SIYPDNGDTS YNQNFKG 8 HC HVR3 anti-FGFR2b GDFAY 9 HVR1 light chain (LC) anti-FGFR2b KASQGVSNDV A 10 LC HVR2 anti-FGFR2b SASYRYT eleven LC HVR3 anti-FGFR2b QQHSTTPYT 12 Heavy chain anti-FGFR2b with N297Q; point mutation N297Q is in bold and underlined QVQLVQSGAE VKKPGSSVKV SCKASGYIFT TYNVHWVRQA PGQGLEWIGS IYPDNGDTSY NQNFKGRATI TADKSTSTAY MELSSLRSED TAVYYCARGD FAYWGQGTLV TVSSASTKGP SVFPLAPSSK STSGGTAALG CLVKDYFPEP VTVSWNSGAL TSGVHTFPAV LQSSGLYSLS SV VTVPSSSL GTQTYICNVN HKPSNTKVDK RVEPKSCDKT HTCPPCPAPE LLGGPSVFLF PPKPKDTLMI SRTPEVTCVV VDVSHEDPEV KFNWYVDGVE VHNAKTKPRE EQY Q STYRVV SVLTVLHQDW LNGKEYKCKV SNKALPAPIE KTISKAKGQP REPQVYTLPP SREEMTK NQV SLTCLVKGFY PSDIAVEWES NGQPENNYKT TPPVLDSDGS FFLYSKLTVD KSRWQQGNVF SCSVMHEALH NHYTQKSLSL SPGK 13 Mature human FGFR2-IIIc N QHWSLIMES VVPSDKGNYT CVVENEYGSI NHTYHLDVVE RSPHRPILQA GLPANASTVV GGDVEFVCKV YSDAQPHIQW IKHVEKNGSK YGPDGLPYLK VLKAAGVNTT DKEIEVLYIR NVTFEDAGEY TCLAGNSIGI SFHSAWLTVL PAPGREKEIT ASPDYLEIAI YCIGVFLIAC MVVT VILCRM KNTTKKPDFS SQPAVHKLTK RIPLRRQVTV SAESSSSMNS NTPLVRITTR LSSTADTPML AGVSEYELPE DPKWEFPRDK LTLGKPLGEG CFGQVVMAEA VGIDKDKPKE AVTVAVKMLK DDATEKDLSD LVSEMEMMKM IGKHKNIINL LGACTQDGPL YVIVEYASKG NLREYLRARR PPGMEYSYDI NRVPEEQMTF KDLVSCTYQL ARGMEYLASQ KCIHRDLAAR NVLVTENNVM KIADFGLARD INNIDYYKKT
TNGRLPVKWM APEALFDRVY THQSDVWSFG VLMWEIFTLG GSPYPGIPVE ELFKLLKEGH RMDKPANCTN ELYMMMRDCW HAVPSQRPTF KQLVEDLDRI LTLTTNEEYL DLSQPLEQYS PSYPDTRSSC SSGDDSVFSP DPMPYEPCLP QYPHINGSVK T 14 EVA FGFR2 N QHWSLIMES VVPSDKGNYT CVVENEYGSI NHTYHLDVVE RSPHRPILQA GLPANASTVV GGDVEFVCKV YSDAQPHIQW IKHVEKNGSK YGPDGLPYLK VLKAAGVNTT DKEIEVLYIR NVTFEDAGEY TCLAGNSIGI SFHSAWLTVL PAPGREKEIT ASPDYLE 15 Gal-FR22 heavy chain variable region of anti-FGFR2 QVQLKQSGPG LVQPSQSLSI TCTVSGFSLT SFGVHWVRQS PGKGLEWLGV IWSGGSTDYN ADFRSRLSIS KDNSKSQIFF KMNSLQPDDT IAYCANFYYG YDDYVMDYWG QGTSVTVSS 16 Heavy chain CDR1 Gal-FR22 anti-FGFR2 SFGVH 17 Heavy chain CDR2 Gal-FR22 anti-FGFR2 VIWSGGSTDYNADFRS 18 Heavy chain CDR3 Gal-FR22 anti-FGFR2 FYYGYDDYVMDY 19 Gal-FR22 light chain variable region of anti-FGFR2 DIQMTQSPSS LSASLGGRVT ITCKASQDIK NYIAWYQHKP GKSPRLLIHY TSTLQPGVPS RFSGSGSGRD YSFSISNLEP EDIATYYCLQ YDDDLYMFGG GTKLDIK 20 Light chain CDR1 Gal-FR22 anti-FGFR2 KASQDIKNYIA 21 Light chain CDR2 Gal-FR22 anti-FGFR2 YTSTLQP 22 Light chain CDR3 Gal-FR22 anti-FGFR2 LQYDDLYM

--->

SEQUENCE LIST

<110> Five Prime Therapeutics, Inc.

<120> ANTI-FGFR2 ANTIBODIES IN COMBINATION WITH CHEMOTHERAPEUTIC

MEDICINES FOR CANCER TREATMENT

<130> 01134-0054-00PCT

<150> US 62/507 053

<151> 05/16/2017

<150> US 62/581 992

<151> 11/06/2017

<160> 22

<170> PatentIn version 3.5

<210> 1

<211> 801

<212> PROTEIN

<213> Homo sapiens

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Arg Pro Ser Phe Ser Leu Val Glu Asp Thr Thr Leu Glu Pro Glu Glu

1 5 10 15

Pro Pro Thr Lys Tyr Gln Ile Ser Gln Pro Glu Val Tyr Val Ala Ala

20 25 30

Pro Gly Glu Ser Leu Glu Val Arg Cys Leu Leu Lys Asp Ala Ala Val

35 40 45

Ile Ser Trp Thr Lys Asp Gly Val His Leu Gly Pro Asn Asn Arg Thr

50 55 60

Val Leu Ile Gly Glu Tyr Leu Gln Ile Lys Gly Ala Thr Pro Arg Asp

65 70 75 80

Ser Gly Leu Tyr Ala Cys Thr Ala Ser Arg Thr Val Asp Ser Glu Thr

85 90 95

Trp Tyr Phe Met Val Asn Val Thr Asp Ala Ile Ser Ser Gly Asp Asp

100 105 110

Glu Asp Asp Thr Asp Gly Ala Glu Asp Phe Val Ser Glu Asn Ser Asn

115 120 125

Asn Lys Arg Ala Pro Tyr Trp Thr Asn Thr Glu Lys Met Glu Lys Arg

130 135 140

Leu His Ala Val Pro Ala Ala Asn Thr Val Lys Phe Arg Cys Pro Ala

145 150 155 160

Gly Gly Asn Pro Met Pro Thr Met Arg Trp Leu Lys Asn Gly Lys Glu

165 170 175

Phe Lys Gln Glu His Arg Ile Gly Gly Tyr Lys Val Arg Asn Gln His

180 185 190

Trp Ser Leu Ile Met Glu Ser Val Val Pro Ser Asp Lys Gly Asn Tyr

195 200 205

Thr Cys Val Val Glu Asn Glu Tyr Gly Ser Ile Asn His Thr Tyr His

210 215 220

Leu Asp Val Val Glu Arg Ser Pro His Arg Pro Ile Leu Gln Ala Gly

225 230 235 240

Leu Pro Ala Asn Ala Ser Thr Val Val Gly Gly Asp Val Glu Phe Val

245 250 255

Cys Lys Val Tyr Ser Asp Ala Gln Pro His Ile Gln Trp Ile Lys His

260 265 270

Val Glu Lys Asn Gly Ser Lys Tyr Gly Pro Asp Gly Leu Pro Tyr Leu

275 280 285

Lys Val Leu Lys His Ser Gly Ile Asn Ser Ser Asn Ala Glu Val Leu

290 295 300

Ala Leu Phe Asn Val Thr Glu Ala Asp Ala Gly Glu Tyr Ile Cys Lys

305 310 315 320

Val Ser Asn Tyr Ile Gly Gln Ala Asn Gln Ser Ala Trp Leu Thr Val

325 330 335

Leu Pro Lys Gln Gln Ala Pro Gly Arg Glu Lys Glu Ile Thr Ala Ser

340 345 350

Pro Asp Tyr Leu Glu Ile Ala Ile Tyr Cys Ile Gly Val Phe Leu Ile

355 360 365

Ala Cys Met Val Val Thr Val Ile Leu Cys Arg Met Lys Asn Thr Thr

370 375 380

Lys Lys Pro Asp Phe Ser Ser Gln Pro Ala Val His Lys Leu Thr Lys

385 390 395 400

Arg Ile Pro Leu Arg Arg Gln Val Thr Val Ser Ala Glu Ser Ser Ser

405 410 415

Ser Met Asn Ser Asn Thr Pro Leu Val Arg Ile Thr Thr Arg Leu Ser

420 425 430

Ser Thr Ala Asp Thr Pro Met Leu Ala Gly Val Ser Glu Tyr Glu Leu

435 440 445

Pro Glu Asp Pro Lys Trp Glu Phe Pro Arg Asp Lys Leu Thr Leu Gly

450 455 460

Lys Pro Leu Gly Glu Gly Cys Phe Gly Gln Val Val Met Ala Glu Ala

465 470 475 480

Val Gly Ile Asp Lys Asp Lys Pro Lys Glu Ala Val Thr Val Ala Val

485 490 495

Lys Met Leu Lys Asp Asp Ala Thr Glu Lys Asp Leu Ser Asp Leu Val

500 505 510

Ser Glu Met Glu Met Met Lys Met Ile Gly Lys His Lys Asn Ile Ile

515 520 525

Asn Leu Leu Gly Ala Cys Thr Gln Asp Gly Pro Leu Tyr Val Ile Val

530 535 540

Glu Tyr Ala Ser Lys Gly Asn Leu Arg Glu Tyr Leu Arg Ala Arg Arg

545 550 555 560

Pro Pro Gly Met Glu Tyr Ser Tyr Asp Ile Asn Arg Val Pro Glu Glu

565 570 575

Gln Met Thr Phe Lys Asp Leu Val Ser Cys Thr Tyr Gln Leu Ala Arg

580 585 590

Gly Met Glu Tyr Leu Ala Ser Gln Lys Cys Ile His Arg Asp Leu Ala

595 600 605

Ala Arg Asn Val Leu Val Thr Glu Asn Asn Val Met Lys Ile Ala Asp

610 615 620

Phe Gly Leu Ala Arg Asp Ile Asn Asn Ile Asp Tyr Tyr Lys Lys Thr

625 630 635 640

Thr Asn Gly Arg Leu Pro Val Lys Trp Met Ala Pro Glu Ala Leu Phe

645 650 655

Asp Arg Val Tyr Thr His Gln Ser Asp Val Trp Ser Phe Gly Val Leu

660 665 670

Met Trp Glu Ile Phe Thr Leu Gly Gly Ser Pro Tyr Pro Gly Ile Pro

675 680 685

Val Glu Glu Leu Phe Lys Leu Leu Lys Glu Gly His Arg Met Asp Lys

690 695 700

Pro Ala Asn Cys Thr Asn Glu Leu Tyr Met Met Met Arg Asp Cys Trp

705 710 715 720

His Ala Val Pro Ser Gln Arg Pro Thr Phe Lys Gln Leu Val Glu Asp

725 730 735

Leu Asp Arg Ile Leu Thr Leu Thr Thr Asn Glu Glu Tyr Leu Asp Leu

740 745 750

Ser Gln Pro Leu Glu Gln Tyr Ser Pro Ser Tyr Pro Asp Thr Arg Ser

755 760 765

Ser Cys Ser Ser Gly Asp Asp Ser Val Phe Ser Pro Asp Pro Met Pro

770 775 780

Tyr Glu Pro Cys Leu Pro Gln Tyr Pro His Ile Asn Gly Ser Val Lys

785 790 795 800

Thr

<210> 2

<211> 444

<212> PROTEIN

<213> Artificial sequence

<220>

<223> alpha-FGFR2b heavy chain

<220>

<221> NOTE

<222> (294)..(294)

<223> Asn297

<400> 2

Gln Val Gln Leu Val Gln Ser Gly Ala Glu Val Lys Lys Pro Gly Ser

1 5 10 15

Ser Val Lys Val Ser Cys Lys Ala Ser Gly Tyr Ile Phe Thr Thr Tyr

20 25 30

Asn Val His Trp Val Arg Gln Ala Pro Gly Gln Gly Leu Glu Trp Ile

35 40 45

Gly Ser Ile Tyr Pro Asp Asn Gly Asp Thr Ser Tyr Asn Gln Asn Phe

50 55 60

Lys Gly Arg Ala Thr Ile Thr Ala Asp Lys Ser Thr Ser Thr Ala Tyr

65 70 75 80

Met Glu Leu Ser Ser Leu Arg Ser Glu Asp Thr Ala Val Tyr Tyr Cys

85 90 95

Ala Arg Gly Asp Phe Ala Tyr Trp Gly Gln Gly Thr Leu Val Thr Val

100 105 110

Ser Ser Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu Ala Pro Ser

115 120 125

Ser Lys Ser Thr Ser Gly Gly Thr Ala Ala Leu Gly Cys Leu Val Lys

130 135 140

Asp Tyr Phe Pro Glu Pro Val Thr Val Ser Trp Asn Ser Gly Ala Leu

145 150 155 160

Thr Ser Gly Val His Thr Phe Pro Ala Val Leu Gln Ser Ser Gly Leu

165 170 175

Tyr Ser Leu Ser Ser Val Val Thr Val Pro Ser Ser Ser Leu Gly Thr

180 185 190

Gln Thr Tyr Ile Cys Asn Val Asn His Lys Pro Ser Asn Thr Lys Val

195 200 205

Asp Lys Arg Val Glu Pro Lys Ser Cys Asp Lys Thr His Thr Cys Pro

210 215 220

Pro Cys Pro Ala Pro Glu Leu Leu Gly Gly Pro Ser Val Phe Leu Phe

225 230 235 240

Pro Pro Lys Pro Lys Asp Thr Leu Met Ile Ser Arg Thr Pro Glu Val

245 250 255

Thr Cys Val Val Val Asp Val Ser His Glu Asp Pro Glu Val Lys Phe

260 265 270

Asn Trp Tyr Val Asp Gly Val Glu Val His Asn Ala Lys Thr Lys Pro

275 280 285

Arg Glu Glu Gln Tyr Asn Ser Thr Tyr Arg Val Val Ser Val Leu Thr

290 295 300

Val Leu His Gln Asp Trp Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val

305 310 315 320

Ser Asn Lys Ala Leu Pro Ala Pro Ile Glu Lys Thr Ile Ser Lys Ala

325 330 335

Lys Gly Gln Pro Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser Arg

340 345 350

Glu Glu Met Thr Lys Asn Gln Val Ser Leu Thr Cys Leu Val Lys Gly

355 360 365

Phe Tyr Pro Ser Asp Ile Ala Val Glu Trp Glu Ser Asn Gly Gln Pro

370 375 380

Glu Asn Asn Tyr Lys Thr Thr Pro Pro Val Leu Asp Ser Asp Gly Ser

385 390 395 400

Phe Phe Leu Tyr Ser Lys Leu Thr Val Asp Lys Ser Arg Trp Gln Gln

405 410 415

Gly Asn Val Phe Ser Cys Ser Val Met His Glu Ala Leu His Asn His

420 425 430

Tyr Thr Gln Lys Ser Leu Ser Leu Ser Pro Gly Lys

435 440

<210> 3

<211> 214

<212> PROTEIN

<213> Artificial sequence

<220>

<223> Anti-FGFR2b light chain

<400> 3

Asp Ile Gln Met Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly

1 5 10 15

Asp Arg Val Thr Ile Thr Cys Lys Ala Ser Gln Gly Val Ser Asn Asp

20 25 30

Val Ala Trp Tyr Gln Gln Lys Pro Gly Lys Ala Pro Lys Leu Leu Ile

35 40 45

Tyr Ser Ala Ser Tyr Arg Tyr Thr Gly Val Pro Ser Arg Phe Ser Gly

50 55 60

Ser Gly Ser Gly Thr Asp Phe Thr Phe Thr Ile Ser Ser Leu Gln Pro

65 70 75 80

Glu Asp Ile Ala Thr Tyr Tyr Cys Gln Gln His Ser Thr Thr Pro Tyr

85 90 95

Thr Phe Gly Gln Gly Thr Lys Leu Glu Ile Lys Arg Thr Val Ala Ala

100 105 110

Pro Ser Val Phe Ile Phe Pro Ser Asp Glu Gln Leu Lys Ser Gly

115 120 125

Thr Ala Ser Val Val Cys Leu Leu Asn Asn Phe Tyr Pro Arg Glu Ala

130 135 140

Lys Val Gln Trp Lys Val Asp Asn Ala Leu Gln Ser Gly Asn Ser Gln

145 150 155 160

Glu Ser Val Thr Glu Gln Asp Ser Lys Asp Ser Thr Tyr Ser Leu Ser

165 170 175

Ser Thr Leu Thr Leu Ser Lys Ala Asp Tyr Glu Lys His Lys Val Tyr

180 185 190

Ala Cys Glu Val Thr His Gln Gly Leu Ser Ser Pro Val Thr Lys Ser

195 200 205

Phe Asn Arg Gly Glu Cys

210

<210> 4

<211> 114

<212> PROTEIN

<213> Artificial sequence

<220>

<223> Anti-FGFR2b heavy chain variable region

<400> 4

Gln Val Gln Leu Val Gln Ser Gly Ala Glu Val Lys Lys Pro Gly Ser

1 5 10 15

Ser Val Lys Val Ser Cys Lys Ala Ser Gly Tyr Ile Phe Thr Thr Tyr

20 25 30

Asn Val His Trp Val Arg Gln Ala Pro Gly Gln Gly Leu Glu Trp Ile

35 40 45

Gly Ser Ile Tyr Pro Asp Asn Gly Asp Thr Ser Tyr Asn Gln Asn Phe

50 55 60

Lys Gly Arg Ala Thr Ile Thr Ala Asp Lys Ser Thr Ser Thr Ala Tyr

65 70 75 80

Met Glu Leu Ser Ser Leu Arg Ser Glu Asp Thr Ala Val Tyr Tyr Cys

85 90 95

Ala Arg Gly Asp Phe Ala Tyr Trp Gly Gln Gly Thr Leu Val Thr Val

100 105 110

Ser Ser

<210> 5

<211> 107

<212> PROTEIN

<213> Artificial sequence

<220>

<223> Anti-FGFR2b light chain variable region

<400> 5

Asp Ile Gln Met Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Val Gly

1 5 10 15

Asp Arg Val Thr Ile Thr Cys Lys Ala Ser Gln Gly Val Ser Asn Asp

20 25 30

Val Ala Trp Tyr Gln Gln Lys Pro Gly Lys Ala Pro Lys Leu Leu Ile

35 40 45

Tyr Ser Ala Ser Tyr Arg Tyr Thr Gly Val Pro Ser Arg Phe Ser Gly

50 55 60

Ser Gly Ser Gly Thr Asp Phe Thr Phe Thr Ile Ser Ser Leu Gln Pro

65 70 75 80

Glu Asp Ile Ala Thr Tyr Tyr Cys Gln Gln His Ser Thr Thr Pro Tyr

85 90 95

Thr Phe Gly Gln Gly Thr Lys Leu Glu Ile Lys

100 105

<210> 6

<211> 5

<212> PROTEIN

<213> Artificial sequence

<220>

<223> HVR1 heavy chain (HC) anti-FGFR2b

<400> 6

Thr Tyr Asn Val His

15

<210> 7

<211> 17

<212> PROTEIN

<213> Artificial sequence

<220>

<223> HVR2 HC anti-FGFR2b

<400> 7

Ser Ile Tyr Pro Asp Asn Gly Asp Thr Ser Tyr Asn Gln Asn Phe Lys

1 5 10 15

gly

<210> 8

<211> 5

<212> PROTEIN

<213> Artificial sequence

<220>

<223> HVR3 HC anti-FGFR2b

<400> 8

Gly Asp Phe Ala Tyr

15

<210> 9

<211> 11

<212> PROTEIN

<213> Artificial sequence

<220>

<223> HVR1 light chain (LC) anti-FGFR2b

<400> 9

Lys Ala Ser Gln Gly Val Ser Asn Asp Val Ala

1 5 10

<210> 10

<211> 7

<212> PROTEIN

<213> Artificial sequence

<220>

<223> HVR2 LC anti-FGFR2b

<400> 10

Ser Ala Ser Tyr Arg Tyr Thr

15

<210> 11

<211> 9

<212> PROTEIN

<213> Artificial sequence

<220>

<223> HVR3 LC anti-FGFR2b

<400> 11

Gln Gln His Ser Thr Thr Pro Tyr Thr

15

<210> 12

<211> 444

<212> PROTEIN

<213> Artificial sequence

<220>

<223> Heavy chain with N297Q anti-FGFR2b

<220>

<221> NOTE

<222> (294)..(294)

<223> N297Q

<400> 12

Gln Val Gln Leu Val Gln Ser Gly Ala Glu Val Lys Lys Pro Gly Ser

1 5 10 15

Ser Val Lys Val Ser Cys Lys Ala Ser Gly Tyr Ile Phe Thr Thr Tyr

20 25 30

Asn Val His Trp Val Arg Gln Ala Pro Gly Gln Gly Leu Glu Trp Ile

35 40 45

Gly Ser Ile Tyr Pro Asp Asn Gly Asp Thr Ser Tyr Asn Gln Asn Phe

50 55 60

Lys Gly Arg Ala Thr Ile Thr Ala Asp Lys Ser Thr Ser Thr Ala Tyr

65 70 75 80

Met Glu Leu Ser Ser Leu Arg Ser Glu Asp Thr Ala Val Tyr Tyr Cys

85 90 95

Ala Arg Gly Asp Phe Ala Tyr Trp Gly Gln Gly Thr Leu Val Thr Val

100 105 110

Ser Ser Ala Ser Thr Lys Gly Pro Ser Val Phe Pro Leu Ala Pro Ser

115 120 125

Ser Lys Ser Thr Ser Gly Gly Thr Ala Ala Leu Gly Cys Leu Val Lys

130 135 140

Asp Tyr Phe Pro Glu Pro Val Thr Val Ser Trp Asn Ser Gly Ala Leu

145 150 155 160

Thr Ser Gly Val His Thr Phe Pro Ala Val Leu Gln Ser Ser Gly Leu

165 170 175

Tyr Ser Leu Ser Ser Val Val Thr Val Pro Ser Ser Ser Leu Gly Thr

180 185 190

Gln Thr Tyr Ile Cys Asn Val Asn His Lys Pro Ser Asn Thr Lys Val

195 200 205

Asp Lys Arg Val Glu Pro Lys Ser Cys Asp Lys Thr His Thr Cys Pro

210 215 220

Pro Cys Pro Ala Pro Glu Leu Leu Gly Gly Pro Ser Val Phe Leu Phe

225 230 235 240

Pro Pro Lys Pro Lys Asp Thr Leu Met Ile Ser Arg Thr Pro Glu Val

245 250 255

Thr Cys Val Val Val Asp Val Ser His Glu Asp Pro Glu Val Lys Phe

260 265 270

Asn Trp Tyr Val Asp Gly Val Glu Val His Asn Ala Lys Thr Lys Pro

275 280 285

Arg Glu Glu Gln Tyr Gln Ser Thr Tyr Arg Val Val Ser Val Leu Thr

290 295 300

Val Leu His Gln Asp Trp Leu Asn Gly Lys Glu Tyr Lys Cys Lys Val

305 310 315 320

Ser Asn Lys Ala Leu Pro Ala Pro Ile Glu Lys Thr Ile Ser Lys Ala

325 330 335

Lys Gly Gln Pro Arg Glu Pro Gln Val Tyr Thr Leu Pro Pro Ser Arg

340 345 350

Glu Glu Met Thr Lys Asn Gln Val Ser Leu Thr Cys Leu Val Lys Gly

355 360 365

Phe Tyr Pro Ser Asp Ile Ala Val Glu Trp Glu Ser Asn Gly Gln Pro

370 375 380

Glu Asn Asn Tyr Lys Thr Thr Pro Pro Val Leu Asp Ser Asp Gly Ser

385 390 395 400

Phe Phe Leu Tyr Ser Lys Leu Thr Val Asp Lys Ser Arg Trp Gln Gln

405 410 415

Gly Asn Val Phe Ser Cys Ser Val Met His Glu Ala Leu His Asn His

420 425 430

Tyr Thr Gln Lys Ser Leu Ser Leu Ser Pro Gly Lys

435 440

<210> 13

<211> 800

<212> PROTEIN

<213> Homo sapiens

<400> 13

Arg Pro Ser Phe Ser Leu Val Glu Asp Thr Thr Leu Glu Pro Glu Glu

1 5 10 15

Pro Pro Thr Lys Tyr Gln Ile Ser Gln Pro Glu Val Tyr Val Ala Ala

20 25 30

Pro Gly Glu Ser Leu Glu Val Arg Cys Leu Leu Lys Asp Ala Ala Val

35 40 45

Ile Ser Trp Thr Lys Asp Gly Val His Leu Gly Pro Asn Asn Arg Thr

50 55 60

Val Leu Ile Gly Glu Tyr Leu Gln Ile Lys Gly Ala Thr Pro Arg Asp

65 70 75 80

Ser Gly Leu Tyr Ala Cys Thr Ala Ser Arg Thr Val Asp Ser Glu Thr

85 90 95

Trp Tyr Phe Met Val Asn Val Thr Asp Ala Ile Ser Ser Gly Asp Asp

100 105 110

Glu Asp Asp Thr Asp Gly Ala Glu Asp Phe Val Ser Glu Asn Ser Asn

115 120 125

Asn Lys Arg Ala Pro Tyr Trp Thr Asn Thr Glu Lys Met Glu Lys Arg

130 135 140

Leu His Ala Val Pro Ala Ala Asn Thr Val Lys Phe Arg Cys Pro Ala

145 150 155 160

Gly Gly Asn Pro Met Pro Thr Met Arg Trp Leu Lys Asn Gly Lys Glu

165 170 175

Phe Lys Gln Glu His Arg Ile Gly Gly Tyr Lys Val Arg Asn Gln His

180 185 190

Trp Ser Leu Ile Met Glu Ser Val Val Pro Ser Asp Lys Gly Asn Tyr

195 200 205

Thr Cys Val Val Glu Asn Glu Tyr Gly Ser Ile Asn His Thr Tyr His

210 215 220

Leu Asp Val Val Glu Arg Ser Pro His Arg Pro Ile Leu Gln Ala Gly

225 230 235 240

Leu Pro Ala Asn Ala Ser Thr Val Val Gly Gly Asp Val Glu Phe Val

245 250 255

Cys Lys Val Tyr Ser Asp Ala Gln Pro His Ile Gln Trp Ile Lys His

260 265 270

Val Glu Lys Asn Gly Ser Lys Tyr Gly Pro Asp Gly Leu Pro Tyr Leu

275 280 285

Lys Val Leu Lys Ala Ala Gly Val Asn Thr Thr Asp Lys Glu Ile Glu

290 295 300

Val Leu Tyr Ile Arg Asn Val Thr Phe Glu Asp Ala Gly Glu Tyr Thr

305 310 315 320

Cys Leu Ala Gly Asn Ser Ile Gly Ile Ser Phe His Ser Ala Trp Leu

325 330 335

Thr Val Leu Pro Ala Pro Gly Arg Glu Lys Glu Ile Thr Ala Ser Pro

340 345 350

Asp Tyr Leu Glu Ile Ala Ile Tyr Cys Ile Gly Val Phe Leu Ile Ala

355 360 365

Cys Met Val Val Thr Val Ile Leu Cys Arg Met Lys Asn Thr Thr Lys

370 375 380

Lys Pro Asp Phe Ser Ser Gln Pro Ala Val His Lys Leu Thr Lys Arg

385 390 395 400

Ile Pro Leu Arg Arg Gln Val Thr Val Ser Ala Glu Ser Ser Ser Ser

405 410 415

Met Asn Ser Asn Thr Pro Leu Val Arg Ile Thr Thr Arg Leu Ser Ser

420 425 430

Thr Ala Asp Thr Pro Met Leu Ala Gly Val Ser Glu Tyr Glu Leu Pro

435 440 445

Glu Asp Pro Lys Trp Glu Phe Pro Arg Asp Lys Leu Thr Leu Gly Lys

450 455 460

Pro Leu Gly Glu Gly Cys Phe Gly Gln Val Val Met Ala Glu Ala Val

465 470 475 480

Gly Ile Asp Lys Asp Lys Pro Lys Glu Ala Val Thr Val Ala Val Lys

485 490 495

Met Leu Lys Asp Asp Ala Thr Glu Lys Asp Leu Ser Asp Leu Val Ser

500 505 510

Glu Met Glu Met Met Lys Met Ile Gly Lys His Lys Asn Ile Ile Asn

515 520 525

Leu Leu Gly Ala Cys Thr Gln Asp Gly Pro Leu Tyr Val Ile Val Glu

530 535 540

Tyr Ala Ser Lys Gly Asn Leu Arg Glu Tyr Leu Arg Ala Arg Arg Pro

545 550 555 560

Pro Gly Met Glu Tyr Ser Tyr Asp Ile Asn Arg Val Pro Glu Glu Gln

565 570 575

Met Thr Phe Lys Asp Leu Val Ser Cys Thr Tyr Gln Leu Ala Arg Gly

580 585 590

Met Glu Tyr Leu Ala Ser Gln Lys Cys Ile His Arg Asp Leu Ala Ala

595 600 605

Arg Asn Val Leu Val Thr Glu Asn Asn Val Met Lys Ile Ala Asp Phe

610 615 620

Gly Leu Ala Arg Asp Ile Asn Asn Ile Asp Tyr Tyr Lys Lys Thr Thr

625 630 635 640

Asn Gly Arg Leu Pro Val Lys Trp Met Ala Pro Glu Ala Leu Phe Asp

645 650 655

Arg Val Tyr Thr His Gln Ser Asp Val Trp Ser Phe Gly Val Leu Met

660 665 670

Trp Glu Ile Phe Thr Leu Gly Gly Ser Pro Tyr Pro Gly Ile Pro Val

675 680 685

Glu Glu Leu Phe Lys Leu Leu Lys Glu Gly His Arg Met Asp Lys Pro

690 695 700

Ala Asn Cys Thr Asn Glu Leu Tyr Met Met Met Arg Asp Cys Trp His

705 710 715 720

Ala Val Pro Ser Gln Arg Pro Thr Phe Lys Gln Leu Val Glu Asp Leu

725 730 735

Asp Arg Ile Leu Thr Leu Thr Thr Asn Glu Glu Tyr Leu Asp Leu Ser

740 745 750

Gln Pro Leu Glu Gln Tyr Ser Pro Ser Tyr Pro Asp Thr Arg Ser Ser

755 760 765

Cys Ser Ser Gly Asp Asp Ser Val Phe Ser Pro Asp Pro Met Pro Tyr

770 775 780

Glu Pro Cys Leu Pro Gln Tyr Pro His Ile Asn Gly Ser Val Lys Thr

785 790 795 800

<210> 14

<211> 356

<212> PROTEIN

<213> Homo sapiens

<400> 14

Arg Pro Ser Phe Ser Leu Val Glu Asp Thr Thr Leu Glu Pro Glu Glu

1 5 10 15

Pro Pro Thr Lys Tyr Gln Ile Ser Gln Pro Glu Val Tyr Val Ala Ala

20 25 30

Pro Gly Glu Ser Leu Glu Val Arg Cys Leu Leu Lys Asp Ala Ala Val

35 40 45

Ile Ser Trp Thr Lys Asp Gly Val His Leu Gly Pro Asn Asn Arg Thr

50 55 60

Val Leu Ile Gly Glu Tyr Leu Gln Ile Lys Gly Ala Thr Pro Arg Asp

65 70 75 80

Ser Gly Leu Tyr Ala Cys Thr Ala Ser Arg Thr Val Asp Ser Glu Thr

85 90 95

Trp Tyr Phe Met Val Asn Val Thr Asp Ala Ile Ser Ser Gly Asp Asp

100 105 110

Glu Asp Asp Thr Asp Gly Ala Glu Asp Phe Val Ser Glu Asn Ser Asn

115 120 125

Asn Lys Arg Ala Pro Tyr Trp Thr Asn Thr Glu Lys Met Glu Lys Arg

130 135 140

Leu His Ala Val Pro Ala Ala Asn Thr Val Lys Phe Arg Cys Pro Ala

145 150 155 160

Gly Gly Asn Pro Met Pro Thr Met Arg Trp Leu Lys Asn Gly Lys Glu

165 170 175

Phe Lys Gln Glu His Arg Ile Gly Gly Tyr Lys Val Arg Asn Gln His

180 185 190

Trp Ser Leu Ile Met Glu Ser Val Val Pro Ser Asp Lys Gly Asn Tyr

195 200 205

Thr Cys Val Val Glu Asn Glu Tyr Gly Ser Ile Asn His Thr Tyr His

210 215 220

Leu Asp Val Val Glu Arg Ser Pro His Arg Pro Ile Leu Gln Ala Gly

225 230 235 240

Leu Pro Ala Asn Ala Ser Thr Val Val Gly Gly Asp Val Glu Phe Val

245 250 255

Cys Lys Val Tyr Ser Asp Ala Gln Pro His Ile Gln Trp Ile Lys His

260 265 270

Val Glu Lys Asn Gly Ser Lys Tyr Gly Pro Asp Gly Leu Pro Tyr Leu

275 280 285

Lys Val Leu Lys Ala Ala Gly Val Asn Thr Thr Asp Lys Glu Ile Glu

290 295 300

Val Leu Tyr Ile Arg Asn Val Thr Phe Glu Asp Ala Gly Glu Tyr Thr

305 310 315 320

Cys Leu Ala Gly Asn Ser Ile Gly Ile Ser Phe His Ser Ala Trp Leu

325 330 335

Thr Val Leu Pro Ala Pro Gly Arg Glu Lys Glu Ile Thr Ala Ser Pro

340 345 350

Asp Tyr Leu Glu

355

<210> 15

<211> 119

<212> PROTEIN

<213> Artificial sequence

<220>

<223> Anti-FGFR2 Gal-FR22 heavy chain variable region

<400> 15

Gln Val Gln Leu Lys Gln Ser Gly Pro Gly Leu Val Gln Pro Ser Gln

1 5 10 15

Ser Leu Ser Ile Thr Cys Thr Val Ser Gly Phe Ser Leu Thr Ser Phe

20 25 30

Gly Val His Trp Val Arg Gln Ser Pro Gly Lys Gly Leu Glu Trp Leu

35 40 45

Gly Val Ile Trp Ser Gly Gly Ser Thr Asp Tyr Asn Ala Asp Phe Arg

50 55 60

Ser Arg Leu Ser Ile Ser Lys Asp Asn Ser Lys Ser Gln Ile Phe Phe

65 70 75 80

Lys Met Asn Ser Leu Gln Pro Asp Asp Thr Ile Ala Tyr Cys Ala Asn

85 90 95

Phe Tyr Tyr Gly Tyr Asp Asp Tyr Val Met Asp Tyr Trp Gly Gln Gly

100 105 110

Thr Ser Val Thr Val Ser Ser

115

<210> 16

<211> 5

<212> PROTEIN

<213> Artificial sequence

<220>

<223> Heavy chain CDR1 Gal-FR22 anti-FGFR2

<400> 16

Ser Phe Gly Val His

15

<210> 17

<211> 16

<212> PROTEIN

<213> Artificial sequence

<220>

<223> Heavy chain CDR2 Gal-FR22 anti-FGFR2

<400> 17

Val Ile Trp Ser Gly Gly Ser Thr Asp Tyr Asn Ala Asp Phe Arg Ser

1 5 10 15

<210> 18

<211> 12

<212> PROTEIN

<213> Artificial sequence

<220>

<223> Heavy chain CDR3 Gal-FR22 anti-FGFR2

<400> 18

Phe Tyr Tyr Gly Tyr Asp Asp Tyr Val Met Asp Tyr

1 5 10

<210> 19

<211> 107

<212> PROTEIN

<213> Artificial sequence

<220>

<223> Anti-FGFR2 Gal-FR22 light chain variable region

<400> 19

Asp Ile Gln Met Thr Gln Ser Pro Ser Ser Leu Ser Ala Ser Leu Gly

1 5 10 15

Gly Arg Val Thr Ile Thr Cys Lys Ala Ser Gln Asp Ile Lys Asn Tyr

20 25 30

Ile Ala Trp Tyr Gln His Lys Pro Gly Lys Ser Pro Arg Leu Leu Ile

35 40 45

His Tyr Thr Ser Thr Leu Gln Pro Gly Val Pro Ser Arg Phe Ser Gly

50 55 60

Ser Gly Ser Gly Arg Asp Tyr Ser Phe Ser Ile Ser Asn Leu Glu Pro

65 70 75 80

Glu Asp Ile Ala Thr Tyr Tyr Cys Leu Gln Tyr Asp Asp Asp Leu Tyr

85 90 95

Met Phe Gly Gly Gly Thr Lys Leu Asp Ile Lys

100 105

<210> 20

<211> 11

<212> PROTEIN

<213> Artificial sequence

<220>

<223> Light chain CDR1 Gal-FR22 anti-FGFR2

<400> 20

Lys Ala Ser Gln Asp Ile Lys Asn Tyr Ile Ala

1 5 10

<210> 21

<211> 7

<212> PROTEIN

<213> Artificial sequence

<220>

<223> Light chain CDR2 Gal-FR22 anti-FGFR2

<400> 21

Tyr Thr Ser Thr Leu Gln Pro

15

<210> 22

<211> 8

<212> PROTEIN

<213> Artificial sequence

<220>

<223> Light chain CDR3 Gal-FR22 anti-FGFR2

<400> 22

Leu Tyr Asp Asp Leu Tyr Met

15

<---

Claims (84)

1. A method of treating gastric cancer in a human subject, comprising administering to the subject a therapeutically effective amount of an antibody to fibroblast growth factor receptor 2 IIIb (anti-FGFR2-IIIb) and administering a modified FOLFOX6 (mFOLFOX6) chemotherapy regimen wherein the anti-FGFR2-IIIb antibody is afucosylated and contains the variable regions of the heavy chain and the light chain, and the variable region of the heavy chain contains: (i) HVR-H1 containing the amino acid sequence of SEQ ID NO: 6; (ii) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; And (iii) HVR-H3 containing the amino acid sequence of SEQ ID NO: 8; and the variable region of the light chain contains: (iv) HVR-L1 containing the amino acid sequence of SEQ ID NO: 9; (v) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; And (vi) HVR-L3 containing the amino acid sequence of SEQ ID NO: 11; where (1) anti-FGFR2-IIIb antibody is administered at a dose of 6-15 mg/kg, (2) at least one intermediate dose of anti-FGFR2-IIIb antibody is administered between two doses (1), (3) mFOLFOX6 chemotherapy includes the administration of 50- 100 mg/m ² oxaliplatin, 100-400 mg/m ² leucovorin and 100-400 mg/m ² 5-fluorouracil (5-FU) by intravenous infusion (IV) or intravenous bolus injection followed by 2200-2400 mg/m ² 5-FU for 44-48 hours, and (4) introduction of antibodies to FGFR2-IIIb according to (1) and mFOLFOX6 according to (3) are carried out simultaneously or sequentially once every 13-15 days. 2. The method according to p. 1, characterized in that the antibody to FGFR2-IIIb has one or more of the following properties: a. binds to FGFR2-IIIb with higher affinity than FGFR2-IIIc or does not bind to FGFR2-IIIc in a detectable manner; b. inhibits FGF2 binding to human FGFR2; c. inhibits FGF7 binding to human FGFR2; d. inhibits human tumor growth in a mouse tumor model; e. induces the activity of antibody-dependent cellular cytotoxicity (ADCC); f. has increased activity of ADCC; And g. is able to increase the number of one or more PD-L1 positive cells, NK cells, CD3+ T cells, CD4+ T cells, CD8+ T cells, and macrophages in tumor tissue in a mouse tumor model compared to controls. 3. The method according to claim 1, characterized in that the heavy chain variable region of the antibody to FGFR2-IIIb contains an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO: 4. 4. The method according to claim 1, characterized in that the light chain variable region of the antibody to FGFR2-IIIb contains an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO: 5. 5. The method according to claim 1, characterized in that the heavy chain variable region of the antibody to FGFR2-IIIb contains the amino acid sequence of SEQ ID NO: 4. 6. The method according to p. 1, characterized in that the variable region of the light chain of the antibody to FGFR2-IIIb contains the amino acid sequence of SEQ ID NO: 5. 7. The method of claim 1, wherein the anti-FGFR2-IIIb antibody comprises a heavy chain variable region containing the amino acid sequence of SEQ ID NO: 4 and a light chain variable region containing the amino acid sequence of SEQ ID NO: 5. 8. The method according to claim 1, characterized in that the heavy chain of the antibody to FGFR2-IIIb contains an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO: 2. 9. The method according to p. 1, characterized in that the light chain of the antibody to FGFR2-IIIb contains an amino acid sequence at least 95% identical to the amino acid sequence of SEQ ID NO: 3. 10. The method according to p. 1, characterized in that the heavy chain of the antibody to FGFR2-IIIb contains the amino acid sequence of SEQ ID NO: 2. 11. The method according to p. 1, characterized in that the light chain of the antibody to FGFR2-IIIb contains the amino acid sequence of SEQ ID NO: 3. 12. The method of claim 1, wherein the anti-FGFR2-IIIb antibody contains a heavy chain containing the amino acid sequence of SEQ ID NO: 2 and a light chain containing the amino acid sequence of SEQ ID NO: 3. 13. The method according to p. 1, characterized in that the antibody to FGFR2-IIIb is chimeric, humanized or human. 14. The method according to any one of paragraphs. 1-6, characterized in that the antibody to FGFR2-IIIb is selected from Fab, Fv, scFv, Fab' and (Fab') ₂ . 15. The method according to p. 1, characterized in that the antibody to FGFR2-IIIb has one or more of the following properties: A. contains an IgG1 or IgG3 heavy chain constant region that lacks fucose at position Asn297; b. contains the light chain constant region κ; c. contains an IgG1 or IgG3 heavy chain constant region that lacks fucose at the Asn297 position and has increased in vitro antibody-dependent cellular cytotoxicity (ADCC) activity compared to an antibody having the same amino acid sequence that is fucosylated at the Asn297 position; And d. contains an IgG1 or IgG3 heavy chain constant region that lacks fucose at position Asn297 and has increased affinity for Fc-gamma RIIIA compared to an antibody having the same amino acid sequence that is fucosylated at position Asn297. 16. The method according to any one of paragraphs. 1-15, characterized in that gastric cancer is locally advanced, inoperable or metastatic. 17. The method according to any one of paragraphs. 1-15, characterized in that the antibody to FGFR2-IIIb is administered at a dose of 10-15 mg/kg, 6 mg/kg, 7 mg/kg, 8 mg/kg, 9 mg/kg, 10 mg/kg, 11 mg /kg, 12 mg/kg, 13 mg/kg, 14 mg/kg or 15 mg/kg. 18. The method according to any one of paragraphs. 1-15, characterized in that the antibody to FGFR2-IIIb is administered once every 14 days. 19. The method according to any one of paragraphs. 1-15, characterized in that the antibody to FGFR2-IIIb is administered in the following dosing regimen: (a) at a dose of 6–15 mg/kg, with an anti-FGFR2–IIIb antibody administered once every 14 days; (b) at a dose of 6 mg/kg, and the antibody to FGFR2-IIIb is administered once every 14 days; (c) at a dose of 10 mg/kg, and the antibody to FGFR2-IIIb is administered once every 14 days; or (d) at a dose of 15 mg/kg, and the antibody to FGFR2-IIIb is administered once every 14 days. 20. The method according to any one of paragraphs. 1-15, characterized in that (1) the antibody to FGFR2-IIIb is administered at a dose of 6-15 mg/kg, 10-15 mg/kg, 6 mg/kg, 7 mg/kg, 8 mg/kg, 9 mg /kg, 10 mg/kg, 11 mg/kg, 12 mg/kg, 13 mg/kg, 14 mg/kg or 15 mg/kg once every 13-15 days or 14 days, and that ( 2) at least one intermediate dose of 3–8 mg/kg, 5–8 mg/kg, 7–8 mg/kg, 3 mg/kg, 4 mg/kg, 5 mg/kg, 6 mg/kg, 7 mg/kg or 8 mg/kg of anti-FGFR2-IIIb antibody is administered between two doses (1) and dose (2) is lower than dose (a). 21. The method according to claim 20, characterized in that: (i) the dose of (1) is 10–15 mg/kg once every 13–15 days; (ii) the dose of (1) is 15 mg/kg once every 13-15 days; (iii) the dose (2) is 5-8 mg/kg and administered 6-8 days after at least one dose (1) and 6-8 days before the next dose (1); (iv) dose (1) is 10–15 mg/kg once every 13–15 days and dose (2) is 7–8 mg/kg administered 6–8 days after at least one dose (1) and 6–8 days before the next dose (1); (v) dose (1) is 15 mg/kg once every 14 days and dose (2) is 7–8 mg/kg administered 7 days after at least one dose of (1) and 7 days before the next doses (1); (vi) the dose of (1) is 15 mg/kg once every 14 days and the dose of (2) is 7.5 mg/kg administered 7 days after at least one dose of (1) and 7 days before the next doses (1); and/or (vii) the dose of (2) is administered after the first dose of (1) in any of (i)-(vi). 22. The method according to claim 17, characterized in that the antibody to FGFR2-IIIb is administered at a dose of 15 mg/kg once every 14 days, and in that 6-8 days after the first administration of the antibody to FGFR2-IIIb, an intermediate dose antibodies to FGFR2-IIIb are administered at a dose of 7.5 mg/kg. 23. The method according to claim 17, characterized in that the antibody to FGFR2-IIIb is administered at a dose of 15 mg/kg once every 14 days, and in that 7 days after the first administration of the antibody to FGFR2-IIIb, an intermediate dose of the antibody to FGFR2 –IIIb is administered at a dose of 7.5 mg/kg. 24. The method according to any one of paragraphs. 1-15 or 21-23, characterized in that mFOLFOX6 includes the introduction of 85 mg / m ² oxaliplatin, 400 mg / m ² leucovorin and 400 mg / m ² 5-fluorouracil (5-FU) by intravenous (IV) infusion or intravenous bolus injection followed by 2400 mg/m ² 5-FU by intravenous infusion over 44-48 hours. 25. The method according to p. 24, characterized in that mFOLFOX6 is administered once every 14 days. 26. The method according to any one of paragraphs. 1-15 or 21-23 characterized in that mFOLFOX6 includes the administration of 85 mg/m ² oxaliplatin, 400 mg/m ² leucovorin and 400 mg/m ² 5-fluorouracil (5-FU) by intravenous (IV) infusion, or intravenous bolus injection followed by 2400 mg/m ² 5-FU by intravenous infusion over 44-48 hours, while mFOLFOX6 is administered once every 14 days. 27. The method according to any one of paragraphs. 1-15 or 21-23, characterized in that one or more injections of mFOLFOX6 are carried out before the introduction of antibodies to FGFR2-IIIb. 28. The method according to p. 27, characterized in that two injections of mFOLFOX6 are carried out before the introduction of antibodies to FGFR2-IIIb. 29. The method according to claim 26, characterized in that the antibody to FGFR2-IIIb is administered on the same day as mFOLFOX6 and before the administration of mFOLFOX6. 30. The method according to any one of paragraphs. 1-15 or 21-23, 25, 28 or 29, characterized in that gastric cancer was previously determined to overexpress FGFR2-IIIb and/or gastric cancer was previously determined to have FGFR2 gene amplification. 31. The method of claim 30, wherein FGFR2-IIIb overexpression is determined by immunohistochemistry (IHC). 32. The method according to any one of paragraphs. 1-15 or 21-23, 25, 28 or 29, wherein the method further comprises determining if the gastric cancer overexpresses FGFR2-IIIb and/or determining if the gastric cancer has FGFR2 gene amplification. 33. The method according to p. 32, characterized in that the overexpression of FGFR2-IIIb is determined by immunohistochemistry (IHC). 34. The method according to claim 31 or 33, characterized in that overexpression has been determined previously or is determined by the +2 or 3+ IHC signal in at least 10%, 20%, 30%, 40% or 50% of the tumor cells. 35. The method according to claim 30, characterized in that the amplification of the FGFR2 gene has been determined previously or is determined by obtaining the ratio of FGFR2 to the centromere of chromosome 10 (CEN10) using fluorescence in situ hybridization (FISH), where the FGFR2 gene is considered amplified if the ratio of FGFR2 /CEN10 as determined by FISH is greater than or equal to 2. 36. The method of claim 30, wherein the FGFR2 amplification has been previously detected or is detected in circulating tumor DNA (cDNA). 37. A method of treating locally advanced, unresectable, or metastatic gastric cancer that overexpresses FGFR2-IIIb in a human subject, comprising administering to the subject: (1) a therapeutically effective amount of an afucosylated anti-FGFR2-IIIb antibody, wherein the antibody contains: (i) HVR-H1 containing the amino acid sequence of SEQ ID NO: 6; (ii) HVR-H2 containing the amino acid sequence of SEQ ID NO: 7; And (iii) HVR-H3 containing the amino acid sequence of SEQ ID NO: 8; (iv) HVR-L1 containing the amino acid sequence of SEQ ID NO: 9; (v) HVR-L2 containing the amino acid sequence of SEQ ID NO: 10; And (vi) HVR-L3 containing the amino acid sequence of SEQ ID NO: 11; And characterized in that the antibody to FGFR2-IIIb is administered intravenously at a dose of 6-15 mg/kg; And (2) modified FOLFOX6 (mFOLFOX6) chemotherapy after (1), which includes the administration of 85 mg/m ² oxaliplatin, 400 mg/m ² leucovorin, and 400 mg/m ² 5-fluorouracil (5-FU) by intravenous infusion or intravenous bolus injections followed by the introduction of 2400 mg / m ² 5-FU by intravenous infusion for 44-48 hours; characterized in that the antibody to FGFR2-IIIb and mFOLFOX6 is administered every 13-15 days; And (3) an intermediate dose of anti-FGFR2-IIIb antibody between administrations of (1), which is lower than the dose according to (1). 38. The method according to p. 37, characterized in that the intermediate dose contains 3-8 mg/kg of antibodies to FGFR2-IIIb and is administered 6-8 days after the first dose of 6-15 mg/kg of antibodies to FGFR2-IIIb and before the second a dose of 6–15 mg/kg of an antibody to FGFR2–IIIb. 39. The method according to claim 38, characterized in that (1) an antibody to FGFR2-IIIb is administered intravenously at a dose of 15 mg/kg, (2) an antibody to FGFR2-IIIb and mFOLFOX6 is administered once every 14 days on the same day, and (3) the intermediate dose contains 7.5 mg/kg of anti-FGFR2-IIIb antibody and is administered 7 days after the first dose of 15 mg/kg of anti-FGFR2-IIIb antibody and before the second dose of 15 mg/kg of anti-FGFR2-IIIb antibody . 40. The method according to claim 38 or 39, characterized in that it was previously determined that gastric cancer overexpresses FGFR2-IIIb, as indicated by an IHC signal of 2+ or 3+ in at least 10% of tumor cells, and / or in which it was previously determined that gastric cancer has an amplification of the FGFR2 gene in ctDNA. 41. The method of claim 38 or claim 39, wherein the subject received two administrations of mFOLFOX6 prior to the first administration of the anti-FGFR2-IIIb antibody. 42. The method according to any one of paragraphs. 37-39, where the antibody to FGFR2-IIIb contains a heavy chain variable region containing the amino acid sequence of SEQ ID NO: 4, and a light chain variable region containing the amino acid sequence of SEQ ID NO: 5. 43. The method according to any one of paragraphs. 37-39, where the antibody to FGFR2-IIIb contains a heavy chain containing the amino acid sequence of SEQ ID NO: 2, and a light chain containing the amino acid sequence of SEQ ID NO: 3.

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