CN116848140A

CN116848140A - Bifunctional anti-PD 1/IL-7 molecules

Info

Publication number: CN116848140A
Application number: CN202180093958.8A
Authority: CN
Inventors: N·普瓦里耶; C·马里; A·莫雷洛; M·塞特
Original assignee: OSE Immunotherapeutics SA
Current assignee: OSE Immunotherapeutics SA
Priority date: 2020-12-17
Filing date: 2021-12-17
Publication date: 2023-10-03
Also published as: CN117412989A

Abstract

The present invention relates to bifunctional molecules comprising IL-7 variants and having a specific scaffold and uses thereof.

Description

Bifunctional anti-PD 1/IL-7 molecules

Technical Field

The present invention belongs to the field of immunotherapy. The present invention provides novel scaffolds comprising bifunctional molecules that comprise variants of IL-7.

Background

Interleukin-7 is an immunostimulatory cytokine member of the IL-2 superfamily and plays an important role in the adaptive immune system by promoting an immune response. Such cytokines activate immune functions through the survival and differentiation of T cells and B cells, the survival of lymphocytes, and the stimulation of Natural Killer (NK) cell activity. IL-7 also regulates lymph node development by Lymphoid Tissue Induction (LTi) cells and promotes survival and division of primary T cells or memory T cells. In addition, IL-7 enhances the immune response in humans by promoting secretion of IL-2 and interferon-gamma. IL-7 receptors are heterodimers, consisting of IL-7Rα (CD 127) and a common gamma chain (CD 132). Gamma chains are expressed on all hematopoietic cell types, while IL-7rα is expressed primarily by lymphocytes, including B and T lymphocyte precursors, naive T cells, and memory T cells. Low expression of IL-7rα was observed on regulatory T cells compared to effector/naive T cells expressing higher levels. Thus, CD127 was used as a surface marker to distinguish between these 2 populations. IL-7Rα is also expressed on natural lymphocytes such as NK and gut-associated lymphoid tissue (GALT) -derived T cells. The IL-7Rα (CD 127) chain is shared with TSLP (tumor stroma lymphopoietin), and CD132 (gamma chain) is shared with IL-2, IL-4, IL-9, IL-15 and IL-21. Two major signaling pathways are induced by CD127/CD 132: (1) The Janus kinase/STAT pathway (i.e., jak-STAT-3 and 5) and (2) the phosphatidylinositol-3 kinase pathway (i.e., PI 3K-Akt). IL-7 administration is well tolerated in patients and results in a relative decrease in CD8 and CD4 cell expansion and CD4+ T regulatory cells. Recombinant naked IL-7 or IL-7 fused to the Fc N-terminal domain of an antibody has been tested in the clinic, the rationale being to increase the IL-7 half-life and enhance the sustained efficiency of the treatment by fusion of the Fc domain.

The recombinant IL-7 cytokine has poor pharmacokinetics, which limits its clinical application. Recombinant IL-7 was rapidly distributed and eliminated following injection, resulting in poor half-life in humans (from 6,8 to 9,5 hours) (Sportes et al, clin Cancer Res.2010Jan15;16 (2): 727-35) or mice (2, 5 hours) (Hyo Jung Nam et al, eur. J. Immunol. 2010.40:351-358). Fusion of the IgG Fc domain to IL-7 prolongs its half-life, as IgG can bind to neonatal Fc receptor (FcRn) and participate in transcytosis and endosomal recycling of the molecule. An increased circulating half-life of the IL-7Fc fusion molecule was observed (t 1/2=13 h), remaining at a detectable level (200 pg/mL) for up to 8 days after administration in mice (Hyo Jung Nam et al, eur.j. Immunol.2010.40:351-358). Although the half-life of IL-7 cytokines fused to Fc domains is prolonged, frequent in vivo injections of the molecule are required to produce a biological effect. In the context of immune cytokine molecules, cytokines are fused with antibodies (e.g., targeting cancer antigens, immune checkpoint blockades, costimulatory molecules … …) to preferentially concentrate cytokines onto target antigen-expressing cells. However, the affinity of IL-7 cytokines for their CD127/CD132 receptors (nanomolar to picomolar range) may be higher than the affinity of antibodies for their targets. Thus, due to the target-mediated drug handling (TMDD) mechanism, cytokines will drive the pharmacokinetics of the product, leading to rapid depletion of the available drugs in vivo. Such rapid elimination of immune cytokines such as IL-2 or IL-15 has been described, indicating that the pharmacokinetic properties of the fusion proteins may directly affect the pharmaceutical properties (List et Neri Clin Pharmacol.2013;5 (Suppl 1): 29-45).

Thus, there remains a great need in the art for new and improved variants of IL-7 that allow for improved distribution and reduced elimination of IL-7 products, particularly bifunctional molecules comprising IL-7. The inventors have made an important step forward through the invention disclosed herein.

Bifunctional molecules are now the subject of development in the field of immunology, especially oncology. In fact, they bring about new pharmacological properties through the co-action of the two targets, which, thanks to targeted repositioning to the tumor, may increase the safety compared to the combination of two different molecules, and may reduce the development and manufacturing costs associated with a single pharmaceutical product. However, these molecules are advantageous, but may also present some inconveniences. The design of bifunctional molecules requires implications for several key attributes such as binding affinity and specificity, folding stability, solubility, pharmacokinetics, effector function, compatibility with the attachment of additional domains, and yield and cost compatible with clinical development. For example, bifunctional molecules targeting PD-1 and carrying IL-7 variants have been described in WO 2020/127377.

However, there is still a strong need for improved scaffolds for bifunctional molecules.

Disclosure of Invention

The inventors provide scaffolds for IL-7 mutation and optimization to improve the distribution and elimination of bifunctional molecules, thereby enhancing in vivo biological effects. The inventors have observed that the combination of IL-7 mutations with optimized scaffolds allows for better distribution of bifunctional molecules and longer in vivo half-life.

The bifunctional molecules provided herein exhibit in particular good in vivo pharmacokinetics and pharmacodynamics, especially compared to bifunctional molecules comprising the wild-type IL-7. In addition, these novel molecules have advantageous and unexpected properties, as detailed below and in the examples.

The present invention relates to bifunctional molecules having a specific scaffold and comprising an interleukin 7 (IL-7) variant (IL-7 m) conjugated to a binding moiety that binds PD-1, wherein the scaffold consists essentially of a dimeric Fc domain, a single monovalent antigen binding domain that binds PD-1 at the N-terminus of one monomer of the Fc domain and either i) a single IL-7m linked at the C-terminus of the same monomer of the Fc domain or ii) a single monovalent antigen binding domain comprising a heavy chain variable chain and a light chain variable chain, and a single IL-7m linked at the C-terminus of the light chain of the antigen binding domain.

This particular scaffold is associated with improved pharmacokinetic profiles. The improvement in pharmacokinetic profile was surprising, as no improvement in this scaffold was observed in the absence of IL-7 m.

Bifunctional molecules with this particular scaffold facilitate cis-targeting of two targets on the same cell, allowing selective delivery of IL-7m to target cells.

In addition, in the context of bifunctional molecules with IL-7, these molecules are able to induce synergistic activation and better antitumor efficacy in vivo. Finally, it is surprising that bifunctional molecules with specific scaffolds have better productivity and avoid by-products due to strand mismatches, which is a major advantage for industrial scale and safety production.

In addition, in addition to improved pharmacokinetic profile and better productivity, a new and advantageous biological efficiency has been found that can increase the activity of effector memory stem cell-like T cells, which are a subset of T cells within tumor-reactive tumors, which are of great interest for their immunological activity.

In a specific aspect of the disclosure, the bifunctional molecule comprises an IL7 variant, in particular a W142H IL7 variant, and an antigen binding domain specific for PD-1 with a specific scaffold, i.e. a molecule called anti-PD-1 x 1IL 7W 142H x 1. The bifunctional molecule features a monovalent antigen binding domain with high affinity and antagonistic activity for PD-1 on one side and a variant IL7 with low affinity for the IL7 receptor (IL 7R) on the other side.

Surprisingly, this bifunctional molecule (anti-PD-1 x 1IL7 w142h x 1) had better tumor-specific T cell preferential targeting (cis targeting) than the same molecule with wild-type IL7 (315-fold compared to 58-fold, see fig. 11C). Furthermore, this molecule blocks the inhibitory activity of tregs and produces better results in eliminating Treg-induced inhibition compared to the same molecule with wild-type IL7 (see figure 19). Unexpectedly, this bifunctional molecule (anti-PD-1 x 1IL7 w142h x 1) affects both Treg elimination and at the same time strong proliferation of T cells, a dual effect, whereas the selected IL7 variant in this molecule has a lower affinity for the IL7 receptor.

As known to those skilled in the art, tumor cells may not be sufficiently eliminated by T cells due to a phenomenon known as T cell depletion observed in many cancers. For example, T cells depleted in the tumor microenvironment as described by Jiang, y, li, y, and Zhu, B (Cell development Dis 6, e1792 (2015)) lead to overexpression of inhibitory receptors, effector cytokine production, and decreased cytolytic activity, leading to failure of cancer elimination, and often to immune evasion of cancer. Recovery of depleted T cells is a clinical strategy for cancer treatment.

Even though the expression of IL7R by depleted T cells is reduced and the affinity of IL7 variants of the molecule for IL7R is low, such bifunctional molecules (anti-PD-1 x 1IL7 w142h x 1) restore proliferation of long-term stimulated T cells while maintaining the survival of depleted T cells at the same level as recombinant IL 7. Surprisingly, such a bifunctional molecule (anti-PD-1 x 1il7 w142h x 1) is able to protect T lymphocytes from apoptosis. In the context of reduced IL7R expression and reduced IL7R affinity, these effects are significant and unpredictable.

Surprisingly, this bifunctional molecule (anti-PD-1 x 1il7 w142h x 1) can induce proliferation of stem cell-like tcf1+cd8T cells (ki67+tcf1+cd8+t cells) (fig. 24), at the same level as rIL7 (data not shown).

Recently, cause et al (2021, nature,596, 126-132) studied mutation-related neoantigen (MANA) -specific CD 8T cells in patients unresponsive to anti-PD-1 treatment, and observed low levels of IL7R on these tumor-specific TILs (tumor infiltrating lymphocytes). Advantageously, the bifunctional molecule (anti-PD-1 x 1IL7 w142h x 1) not only restores proliferation, but also maintains survival of long-term stimulated T cells, despite lower affinity for IL7R and reduced IL7R expression in depleted T cells.

4 different preclinical in vivo models have been used for further treatment validation: in these in vivo preclinical models, bifunctional molecules (anti-PD-1 x 1IL7 w142h x 1) increased survival or completely inhibited tumor growth surprisingly improved therapeutic efficacy was observed compared to the same molecules with wild type IL7 or anti-PD-1 antibodies.

In particular, the PD 1-resistant Hepa1.6 model is of particular interest because tumor T cells are excluded from the tumor (Gauttier et al 2020,Clin Invest,130,6109-6123). In this model, no efficacy was expected for anti-PD 1, and the bifunctional molecule (anti-PD-1 x 1IL7 w142h x 1) achieved a 60% full tumor response, significantly better than the same molecule with wild-type IL7 (47%) (fig. 21). In addition, this molecule can promote selective expansion of stem cell-like memory cd8+ TIL (fig. 22). This is of particular interest in the context of models that exhibit tumor T cell depletion. Although T cells were excluded from the tumor in this drug resistance model, CD8 TIL composition increased significantly and T cell subsets changed significantly after treatment with bifunctional molecules (anti-PD-1 x 1il7 w142h x 1). Very low tregs, high cd8+ T cells and highly proliferative and stem cell-like memory T cell subsets were observed (figures 23 and 24). In contrast, this molecule provides a significant reduction in T cell depletion compared to anti-PD-1 treatment. This powerful advantage, particularly in TILS, is illustrated in the detailed examples, which show the intratumoral proliferation of stem cell-like memory CD 8T cell subsets (tcf1+tox-cells) of this bifunctional molecule. This proliferation allows for the acquisition of an active stem cell-like memory T cell pool. These stem T cells represent an intermediate stage of differentiation between: i) Naive T cells that are not tumor antigen specific or numerous in the presence of anti-PD 1 drugs against tumor cells (the naive T cells are PD1 negative), and ii) mature depleted T cells (particularly T cells that have been completely depleted) that are undernumbers or have been over-stimulated and no longer respond to anti-PD 1 therapy. These depleted T cells are stressed cells that undergo apoptosis as shown by their genetic profile, whereas the stem cell-like memory T cell (tcf1+) pool is able to proliferate and differentiate into a large number of T cells, enabling a longer lasting higher anti-tumor response.

Bifunctional molecules (anti-PD-1 x 1il7w142h 1) acquired a broad memory anti-tumor response, as demonstrated by tumor re-challenge in mice cured of the same tumor type (3 tumor models were tested (PD 1 sensitive model (AK 7 in situ); PD1 partial sensitive model (MC 38 ectopic) and PD1 drug resistant model (hepa 1.6 in situ)). These pre-treated animals without any new therapy did not develop any new tumors, establishing the ability of the bifunctional molecules (anti-PD-1 x 1il7w142h 1) to provide long term protection by activation of the memory T cell subset (figure 20B).

Human Peripheral Blood Mononuclear Cells (PBMC) from 4 different human donors were used in a TNBC humanized mouse model to assess the activity of bifunctional molecules (anti-PD-1 x 1il7w142h x 1) under humanized conditions. The effect of the bifunctional molecule (anti-PD-1 x 1il7w142h x 1) on tumor growth was significantly more excellent compared to the anti-PD-1 antibody, significantly reducing tumor growth (fig. 25). The same excellent effect, in particular an increase in ifnγ secretion in serum, was also observed in another humanized mouse model (lung cancer), which is a direct effect of inducing a response (fig. 26).

In summary, despite the lower affinity for IL7R and reduced expression of IL7R on target cells, bifunctional molecules (anti-PD-1 x 1IL7w142h x 1) are able to restore the cancer immune cycle by synergistic effects on TCR signaling, promoting T effector expansion while suppressing Treg, promoting mucosal T cell migration, and eventually by reactivating depleted T cells. Surprisingly, the effect is superior or equal to that of which with recombinant IL7 or the same molecule with wild-type IL 7.

The present invention relates to bifunctional molecules comprising a single antigen binding domain and a single IL-7 variant,

-wherein the bifunctional molecule comprises a first monomer comprising an antigen binding domain covalently linked by a C-terminus to the N-terminus of a first Fc chain (optionally via a peptide linker) and a second monomer comprising a second, complementary Fc chain free of antigen binding domain and free of IL-7 variants;

-wherein i) the IL-7 variant is covalently linked to the C-terminus of the first Fc chain, optionally via a peptide linker; or ii) the single antigen binding domain comprises a heavy chain variable chain and a light chain variable chain, and the IL-7 variant is covalently linked to the C-terminus of the light chain;

-wherein the antigen binding domain binds to PD-1; and

-wherein the IL-7 variant exhibits at least 75% identity with wild-type human IL-7 (wth-IL-7), the wild-type human IL-7 (wth-IL-7) comprises or consists of the amino acid sequence of SEQ ID NO:1 and the IL-7 variant i) reduces the affinity of the IL-7 variant for IL-7 receptor (IL-7R) compared to the affinity of wth-IL-7 for IL-7R and ii) improves the pharmacokinetics of a bifunctional molecule comprising the IL-7 variant compared to a bifunctional molecule comprising wth-IL-7.

In particular, the IL-7 variant comprises at least one amino acid mutation selected from the group consisting of: (i) W142G, W142A, W142V, W142C, W142L, W142I, W142M, W142H, W Y and W142F, preferably W142H, W142F or W142Y, (ii) C2S-C141S and C47S-C92S, C S-C141S and C34S-C129S, or C47S-C92S and C34S-C129S, (iii) D74E, D Q or D74N, iv) Q11E, Y12F, M17L, Q E and/or K81R; or any combination thereof, and the amino acid numbers are shown as SEQ ID NO: 1.

Preferably, the IL-7 variant comprises an amino acid substitution selected from the group consisting of W142H, W142F and W142Y, the amino acid numbers of which are shown in SEQ ID NO. 1. More preferably, the IL-7 variant comprises the amino acid substitution W142H. Even more preferably, the IL-7 variant comprises SEQ ID NO:2-15 or a sequence represented by SEQ ID NO: 2-15. Most preferably, the IL-7 variant comprises or consists of the amino acid sequence shown in SEQ ID NO. 5.

In a particular aspect, the IL-7 variant is linked to the C-terminus of the first Fc chain, preferably through its N-terminus.

In another aspect, the bifunctional molecule comprises a heavy chain constant domain, preferably an Fc domain, of human IgGl, optionally with a substitution or combination of substitutions selected from: T250Q/M428L; M252Y/S254T/T256 E+H2433K/N434F; E233P/L234V/L235A/G236A+A327G/A330S/P331S; E333A; S239D/A330L/I332E; P257I/Q311; K326W/E333S; S239D/I332E/G236A; N297A; L234A/L235A; n297A+M252Y/S254T/T256E (YTE); n297A+N298A+M252Y/S254T/T256E+K444A, K322A, K444A, K444E, K D, K444 5226 444 329GL234A/L235A/P329G, M428L, L309D, Q311H, N434 428L+N434S (LS) and L309D+Q311H+N434S (DHS), preferably selected from the group consisting of optional N297A optionally in combination with M252Y/S254T/T256E and L234A/L235A or L234A/L235A/P329G. Preferably, the substitution or combination of substitutions is selected from the following: T250Q/M428L; M252Y/S254T/T256 E+H2433K/N434F; E233P/L234V/L235A/G236A+A327G/A330S/P331S; E333A; S239D/A330L/I332E; P257I/Q311; K326W/E333S; S239D/I332E/G236A; N297A; L234A/L235A; n297A+M252Y/S254T/T256E; K322A and K444A, preferably selected from N297A optionally in combination with M252Y/S254T/T256E, and L234A/L235A.

Alternatively, the bifunctional molecule comprises a heavy chain constant domain, preferably an Fc domain, of human IgG4, optionally with a substitution or combination of substitutions selected from the group consisting of: S228P; L234A/L235A, S228P+M252Y/S254T/T256+K444A, K444E, K444D, K444G, K444S, P329G and L234A/L235A/P329G. Preferably, the substitution or combination of substitutions is selected from the following: S228P; L234A/L235A, S228P+M252Y/S254T/T256E and K444A.

In a specific aspect, the bifunctional molecule according to the invention comprises an Fc domain derived from IgGl or IgG4 comprising the mutation LALA (L234A/L352A) or LALA PG (L234A/L235A/P329G).

In one aspect, the first Fc chain and the second Fc chain form a heterodimeric Fc domain, particularly a knob heterodimeric Fc domain. In particular, the first Fc chain is a mortar or H chain and comprises the substitutions T366S/L368A/Y407V/Y349C and optionally N297A, and the second Fc chain is a pestle or K chain comprising the substitutions T366W/S354C and optionally N297A. Preferably, the first Fc chain is a mortar or H chain and comprises the substitutions T366S/L368A/Y407V/Y349C and N297A, and the second Fc chain is a pestle or K chain and comprises the substitutions T366W/S354C and N297A. More specifically, the second Fc chain comprises or consists of SEQ ID NO. 75 and/or the first Fc chain comprises or consists of SEQ ID NO. 77.

In a very specific aspect, the bifunctional molecule according to the invention comprises a first monomer comprising an antigen binding domain covalently linked by a C-terminus to the N-terminus of a first heterodimeric Fc chain (optionally via a peptide linker) covalently linked by a C-terminus to the N-terminus of the IL-7 variant (optionally via a peptide linker) and a second monomer comprising a complementary second heterodimeric Fc chain free of antigen binding domain.

In another aspect, in the bifunctional molecules disclosed herein, the IL-7 variant is fused to the antigen binding domain via a peptide linker selected from the group consisting ofOr the Fc domain: GGGGS (SEQ ID NO: 68), GGGGSGGGS (SEQ ID NO: 67), GGGGSGGGGS (SEQ ID NO: 69) and GGGGSGGGGSGGGGS (SEQ ID NO: 70), preferably (GGGGS) ₃ . Preferably, the IL-7 variant is fused to the antigen binding domain or the Fc domain by a peptide linker of SEQ ID 70.

In one aspect, in a bifunctional molecule according to the invention, the antigen binding domain is a Fab domain, fab', single chain variable fragment (scFV) or single domain antibody (sdAb). Preferably, the antigen binding domain is a Fab domain or Fab'.

In particular, the antigen binding domain is derived from an antibody selected from the group consisting of: palbociclib, nivolumab, pidil mab, cimetidine Li Shan, carlizumab, AUNP12, AMP-224, age-2034, BGB-a317, spatazumab, MK-3477, SCH-900475, PF-06801591, JNJ-63723283, ji Nuoli mu mab, LZM-009, BCD-100, SHR-1201, BAT-1306, AK-103, MEDI-0680, MEDI0608, JS001, BI-754091, CBT-501, incsler 1210, TSR-042, GLS-010, AM-0001, STI-1110, age 2034, MGA012 or IBI308, 5C4, 17D8, 2D3, 4H1, 4a11, 7D3 and 5F4. Preferably, the antigen binding domain is derived from an antibody selected from the group consisting of: palbociclib, nivolumab, pidil mab, cimetidine Li Shan, carlizumab, spatazumab and Ji Nuoli mu mab. Even more preferably, the antigen binding domain is derived from palbociclizumab or nivolumab.

In a very specific aspect, the antigen binding domain of the bifunctional molecule according to the invention comprises or consists essentially of: (i) A heavy chain comprising CDR1 of SEQ ID NO:51, CDR2 of SEQ ID NO:53 and CDR3 of SEQ ID NO:55, 56, 57, 58, 59, 60, 61 or 62; and (ii) a light chain comprising CDR1 of SEQ ID NO. 64, 65, 89, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16 or 90. Preferably, the antigen binding domain comprises or consists essentially of: (i) A heavy chain comprising the CDRL of SEQ ID NO. 51, the CDR2 of SEQ ID NO. 53 and the CDR3 of SEQ ID NO. 61; and (ii) a light chain comprising CDR1 of SEQ ID NO:65, CDR2 of SEQ ID NO:66 and CDR3 of SEQ ID NO: 16.

More preferably, the antigen binding domain comprises or consists essentially of: (a) A heavy chain variable region (VH) comprising or consisting of the amino acid sequence of SEQ ID NO:18, 19, 20, 21, 22, 23, 24 or 25; (b) A light chain variable region (VL) comprising or consisting of the amino acid sequence of SEQ ID NO. 27, SEQ ID NO. 28, SEQ ID NO. 88 or SEQ ID NO. 99. Even more preferably, the antigen binding domain comprises or consists essentially of the heavy chain variable region (VH) of SEQ ID NO. 24 and the light chain variable region (VL) of SEQ ID NO. 28.

In a very specific aspect, the bifunctional molecule according to the invention comprises an antigen binding domain comprising or consisting essentially of the heavy chain variable region (VH) of SEQ ID NO. 24 and the light chain variable region (VL) of SEQ ID NO. 28, and the IL-7 variant comprises the amino acid substitution W142H, the amino acid numbering being as shown in SEQ ID NO. 1, preferably the IL-7 variant comprises or consists essentially of SEQ ID NO. 5.

Preferably, in the bifunctional molecule according to the present invention:

(i) The antigen binding domain comprises or consists essentially of the heavy chain variable region (VH) of SEQ ID NO. 24 and the light chain variable region (VL) of SEQ ID NO. 28,

(ii) The IL-7 variant comprises or consists essentially of the sequence defined by SEQ ID 5,

(iii) The second Fc chain comprises or consists of SEQ ID NO. 75 and/or the first Fc chain comprises or consists of SEQ ID NO. 77.

Preferably, such bifunctional molecules further comprise a peptide linker of SEQ ID NO. 70.

In a very specific aspect, the bifunctional molecule according to the invention comprises a first monomer of SEQ ID NO. 83, a second monomer of SEQ ID NO. 75 and a third monomer of SEQ ID NO. 37, 38 or 80, preferably SEQ ID NO. 38 or 80. Preferably, the bifunctional molecule comprises a first monomer comprising or consisting of SEQ ID NO. 83, a second monomer comprising or consisting of SEQ ID NO. 75, or SEQ ID NO. 75, and a third monomer comprising or consisting of SEQ ID NO. 80.

The invention also relates to an isolated nucleic acid sequence or a set of isolated nucleic acid molecules encoding a bifunctional molecule according to the present disclosure.

The invention also relates to a host cell comprising an isolated nucleic acid sequence or a set of isolated nucleic acid molecules encoding a bifunctional molecule according to the invention.

The invention also relates to a pharmaceutical composition comprising a bifunctional molecule, a nucleic acid or a host cell according to the present disclosure, optionally comprising a pharmaceutically acceptable carrier.

Finally, the present invention relates to a bifunctional molecule, a nucleic acid, a host cell or a pharmaceutical composition according to the invention for use as a medicament, in particular for the treatment of cancer or infectious diseases; use of a bifunctional molecule, nucleic acid, host cell or pharmaceutical composition according to the invention for the preparation of a medicament, in particular for the treatment of cancer or infectious diseases; and methods of treating a disease, particularly cancer or an infectious disease, in a subject comprising administering a therapeutically effective amount of a bifunctional molecule, nucleic acid, host cell, or pharmaceutical composition according to the present disclosure.

Optionally, the present invention relates to a bifunctional molecule, nucleic acid, host cell or pharmaceutical composition according to the present disclosure for use in the treatment of cancer or viral infection by stimulating effector memory stem cell-like T cells; use of a bifunctional molecule, nucleic acid, host cell or pharmaceutical composition according to the invention for the preparation of a medicament, in particular for the treatment of cancer or viral infection by stimulating effector memory stem cell-like T cells; a method of treating cancer or a viral infection in a subject comprising administering a therapeutically effective amount of a bifunctional molecule, nucleic acid, host cell, or pharmaceutical composition according to the present disclosure, thereby stimulating effector memory stem cell-like T cells.

Specifically, the cancer is selected from the following: hematopoietic cancers, solid cancers, carcinomas, cervical cancers, colorectal cancers, esophageal cancers, gastric cancers, gastrointestinal cancers, head and neck cancers, renal cancers, liver cancers, lung cancers, lymphomas, gliomas, mesothelioma, melanoma, gastric cancers, cancers induced by urinary tract cancer environments, metastatic or non-metastatic cancers, melanoma, malignant mesothelioma, non-small cell lung cancers, renal cell cancers, hodgkin's lymphoma, head and neck cancers, urothelial cancers, colorectal cancers, hepatocellular carcinoma, small cell lung cancers, metastatic merck cell cancers, gastric or gastroesophageal cancers, cervical cancers, hematopoietic lymphomas, angioimmunoblastic T cell lymphomas, myelodysplastic syndromes, acute myeloid leukemia, kaposi's sarcoma; cervical cancer, anal cancer, penile cancer and vulvar squamous cell carcinoma associated with human papillomavirus, and oropharyngeal cancer; b-cell non-hodgkin lymphomas (NHL), including diffuse large B-cell lymphomas, burkitt's lymphomas, plasmablasts, primary central nervous system lymphomas, HHV-8 primary exudative lymphomas, classical hodgkin lymphomas, and lymphoproliferative diseases associated with epstein-barr virus (EBV) and/or kaposi's sarcoma herpesvirus; hepatocellular carcinoma associated with hepatitis b and/or c virus; merck cell carcinoma associated with merck cell polyoma virus (MPV); and cancers associated with Human Immunodeficiency Virus (HIV) infection.

Specifically, the viral infection is caused by a virus selected from the group consisting of: HIV, hepatitis viruses such as hepatitis a, b or c, herpes viruses such as VZV, HSV-1, HAV-6, HSV-II, CMV and epstein-barr virus, adenovirus, influenza virus, flavivirus, epstein barr virus, rhinovirus, coxsackievirus, coronavirus, respiratory syncytial virus, mumps virus, rotavirus, measles virus, rubella virus, parvovirus, vaccinia virus, HTLV virus, dengue virus, papilloma virus, mollusc virus, polio virus, rabies virus, JC virus and arbovirus encephalitis virus.

Finally, the present invention relates to a bifunctional molecule, a nucleic acid, a host cell or a pharmaceutical composition for use in combination with a therapeutic agent or therapy selected from the group consisting of: chemotherapy, radiation therapy, targeted therapy, anti-angiogenic agents, hypomethylating agents, cancer vaccines, epitopes or neoepitopes from tumor antigens, bone marrow checkpoint inhibitors, immunotherapy and HDAC inhibitors. In particular, the therapeutic agent is an immune checkpoint blocker or activator of adaptive immune cells (T and B lymphocytes) selected from the group consisting of: anti-CTLA 4, anti-CD 2, anti-CD 28, anti-CD 40, anti-HVEM, anti-BTLA, anti-CD 160, anti-TIGIT, anti-TIM-1/3, anti-LAG-3, anti-2B 4, anti-OX 40, anti-CD 40 agonist, CD40-L, TLR agonist, anti-ICOS, ICOS-L and B cell receptor agonist. Such combinations may be particularly useful in the treatment of cancer or viral infections, such as disclosed herein.

Drawings

Fig. 1: schematic diagrams of different molecules used in examples 1 and 2.

Fig. 2: the anti-PD-1 IL7W142H mutant exhibits high binding efficiency to PD-1 and antagonizes PDL1 binding. PD-1 binding ELISA assay. Human recombinant PD-1 (rPD 1) protein was immobilized and antibodies were added at different concentrations. The use of an anti-human Fc antibody conjugated to peroxidase was revealed. Colorimetric assays were performed at 450nm using TMB substrate. anti-PD-1 with 1 anti-PD-1 (anti-PD-1*1 (gray)) or 2 anti-PD-1 arms (anti-PD-1*2) was tested as a control. Bifunctional molecules comprising IL7 variants (anti-PD-1 x 2IL7w142h x 2 +.black), (anti-PD-1 x 2IL7w142h x 1 ■ black), (anti-PD-1 x 1IL 7w142h x 2+.grey), (anti-PD-1 x 1IL 7w142h x 1 gray) were also tested. B. The antagonistic capacity to block PD-1/PD-L1 was measured by ELISA. PD-L1 was immobilized and complex antibody+biotinylated recombinant human PD-1 was added. The complex was generated with fixed concentrations of PD1 (0.6 μg/mL) and different concentrations of anti-PD 1 x 2il7w142h x 1 (■ plain), anti-PD 1 x 2il7w142h x 2 (o dashed), anti-PD-1*1 (grey @ dashed), anti-PD 1 x 1il 7w142h x 2 (grey ∈plain grey line) or anti-PD 1 x 1il 7w142h x 1 (grey ∈plain grey line). All constructs tested contained GGGGSGGGGSGGGGS linkers between the Fc and IL-7 domains.

Fig. 3: the anti-PD-1 IL7 molecules constructed with monovalent or bivalent anti-PD-1 and an IL-7W142H cytokine are highly potent in activating pSTAT5.A. PD-1/CD127 binding against PD-1IL-7W142H bifunctional molecules. PD-1 recombinant protein was immobilized, and then bifunctional molecules and an immobilized amount of CD127 recombinant protein (histidine tag, sino ref 10975-H08H) were added at different concentrations. The disclosure was made using a mixture of anti-histidine antibodies conjugated with biotin and streptavidin conjugated with peroxidase. Colorimetric assays were performed at 450nm using TMB substrate. anti-PD 1 x 2il7w142h 1 x 1 (■) or anti-PD 1 x 2il7w142h x 2 (++gray) were tested. B. pSTAT5 signaling assays were performed using the anti-PD-1*2 backbone fused to IL-7w142 x 1 cytokine. Human PBMCs isolated from peripheral blood of healthy volunteers were incubated with anti-PD 1 x 2il7wt x 2 (×2) or anti-PD 1 x 2il7w142h x 1 (■ dashed line) for 15 min. Cells were then fixed, permeabilized and stained with anti-CD 3-BV421 and anti-pSTAT 5 AF647 (clone 47/Stat5 (pY 694)). Data were obtained by calculating MFI% pstat5+ cells in cd3+ populations. C. pSTAT5 signaling after treatment with anti-PD-1 x 1il 7w142h 1 (+) anti-PD-1 x 2il7wt 2 (■) or anti-PD 1 x 2il7w142h 1 (+). All tested W142H constructs contained IgG1m and GGGGSGGGGSGGGGS linkers between Fc and IL-7 domains.

Fig. 4: monovalent or bivalent constructed anti-PD-1 IL7 molecules significantly promote T cell proliferation in vivo. Mice were intraperitoneally injected with one dose (34 nM/kg) of anti-PD-1 IL-7W142H molecule (anti-PD-1 x 2IL 7W142H 1, anti-PD-1 x 1IL 7W142H 2) or isotype control. On day 4, blood was collected and T cells were stained with anti-CD 3, anti-CD 8, anti-CD 4 and ki67 proliferation markers. The percentage of KI67 in the cd3cd4+ and cd3cd8+ populations was quantified. Statistical significance (< 0.05) was calculated by one-way analysis of variance (ANOVA) test for multiple comparisons with control mice, 2 independent experiments n=2 to 8 mice per group.

Fig. 5: anti-PD-1 x 2il7 x 1, anti-PD-1 x 1il7 x 2 synergistically activate TCR signaling. Promega PD-1/PD-L1 bioassay: (1) Effector T cells (Jurkat stably expressing PD-1, NFAT-induced luciferase) and (2) activating target cells (CHO K1 cells stably expressing PDL1 and designed to activate the surface proteins of homologous TCRs in an antigen-independent manner). Addition of BioGlo ^TM After fluorescein, luminescence was quantified and reflected T cell activation. A. anti-PD 1 x 2 (++black), anti-PD-1 x 2il 7w142h 1 (ζwhite) were added at a series of concentrations. Use of isotype antibodies As activated negative control (■) b. A combination of anti-PD-1*1 + isoform IL7W142H x 2 control (≡dotted line), anti-PD-1 x 1IL 7W142H x 2 (≡grey), anti-PD-1 x 1IL 7W142H 1 (≡grey) was added at a series of concentrations. All tested W142H constructs contained IgG1m and GGGGSGGGGSGGGGS linkers between the Fc and IL-7 domains.

Fig. 6: anti-PD-1 x 2il7 x 1, anti-PD-1 x 1il7 x 2w142h mutants preferentially bind to and activate pSTAT5 signaling in PD-1+cd127+ cells compared to PD-1-cd127+ cells. U937 cells expressing cd127+ or co-expressing cd127+ and PD-1+ cells were stained with cell proliferation dye (CPDe 450 or CPDe 670) and co-cultured at a 1:1 ratio prior to incubation with different concentrations of anti-PD-1 IL-7 bifunctional molecule. Following incubation, quantification was performed by flow cytometry against human IgG PE staining and pSTAT5 activation. A. EC50 binding (nM) was calculated for each cell type and each structure. B. The EC50 pSTAT5 (nM) was calculated for each cell type and each construct. After treatment with the bifunctional molecule, the cells were fixed, permeabilized and stained with AF 647-labeled anti-pSTAT 5 (clone 47/Stat5 (pY 694)). pSTAT5 activation. EC50 (nM) were calculated for each construct and for each cell type U937 PD-1+cd127+ (white histogram) and U937PD-1-cd127+ (black histogram). n=2 independent experiments. In this assay anti-PD-1 x 2IL 7w142 x 1, anti-PD-1 x 1IL 7w142 x 1 and anti-PD-1 x 1IL 7w142 x 2 were tested and included IgG1m isotype and ggggsggggsggs linkers between Fc and IL-7 domains.

Fig. 7: pharmacokinetics after intraperitoneal injection of anti-PD-1 x 2il7 x 1, anti-PD-1 x 1il7 x 2w142h mutant molecules. Humanized PD1 mice were intraperitoneally injected with a dose (34 nM/kg) of anti-PD-1*2IL7 IL7*2IgG4m (. DELTA.), anti-PD-1*2IL7 W142H*1IgG1m (. DELTA.), anti-PD-1*1IL7 W142H*1IgG1m (. DELTA.) or anti-PD-1*1IL7 W142H*2IgG1m (. Smallcircle. Gray). The concentration of drug in serum was assessed by ELISA 72 hours post injection.

Fig. 8: productivity of anti-PD-1/IL 7 bifunctional antibodies in mammalian cells. CHO-S cells were transiently transfected with DNA encoding anti-PD-1*2/IL 7 x 1 or anti-PD-1*1/IL 7 x 1 molecules at a ratio of (1:3:3; strand a: strand B: VL). The supernatant containing the antibodies was purified using protein a chromatography. The amount of bifunctional antibody obtained after purification was quantified by UV spectrometry (DO 280 nm) and normalized to the throughput. Original data productivity of the construct.

Fig. 9: size exclusion chromatography of anti-PD-1*1/IL-7wt.1 (A) and anti-PD-1*1/IL-7v.1 (B). Purified antibodies were isolated according to their size using gel filtration chromatography using SuperDex 200 (10/300 GL). Peaks corresponding to aggregates, heterodimeric antibodies and Fc homodimers are shown on the graph and the percentage of compound is calculated.

Fig. 10: anti-PD-1 x/IL 7 x 1 molecules activate pSTAT5 with high potency. Fig. 10A. pSTAT5 signaling assays were performed on human primary T cells treated with anti-PD-1*1/IL-21 x 1, anti-PD-1*1/IL-15 x 1, anti-PD-1*1/IL-7 wt x 1, anti-PD-1*1/IL-7 v x 1. Human PBMCs isolated from peripheral blood of healthy volunteers were incubated with these molecules for 15 minutes. Cells were then fixed, permeabilized and stained with anti-CD 3-BV421 and anti-pSTAT 5AF647 (clone 47/Stat5 (pY 694)). The data corresponds to% pstat5+ cells entering the cd3+ population. Fig. 10B. pSTAT5 signaling to the human cd127+cd132+u937 cell line after treatment with anti-PD-1 x 2il7v x 2 (×t) or anti-PD-1 x 1il7v1 x 1 (Δ) molecules. The left plot corresponds to the percentage of pstat5+ cells, and the right plot corresponds to EC50 (nM) calculated from the concentration required to reach 50% of pstat5 activation. Data represent mean +/-SD of 3 independent experiments.

Fig. 11: the anti-PD-1*1/IL 7 x 1 molecule preferentially binds to PD-1+ cells with high efficiency relative to PD-1-cells. Fig. 11A. Binding of anti-PD-1*1/IL-7wt 1 molecules on PD-1+cd127+u937 cells (plateau) versus PD-1-cd127+u937 cell line (dashed line). Fig. 11B. Binding of anti-PD-1*1/IL-7v 1 molecules on PD-1+cd127+u937 cells (plateau) versus PD-1-cd127+u937 cell line (dashed line). Fig. 11C. Comparison of pSTAT5 activation in PD-1+CD127+ cells relative to PD-1-cell CD127+ cells. EC50 nM ratios of pSTAT5 activation on PD-1+cd127+ (white histogram) versus PD-1-cd127+ cells (black histogram) were calculated and reported graphically. N=3 independent experiments.

Fig. 12: anti-PD-1 x 1il7 x 1 synergistically activates TCR signaling. Promega PD-1/PD-L1 bioassay: (1) Effector T cells (Jurkat stably expressing PD-1, NFAT-induced luciferase) and (2) activation target cells (stably expressing PD-L1 and designed for use in a cell culture)CHO K1 cells that activate the surface proteins of homologous TCRs in an antigen-independent manner). Addition of BioGlo ^TM After fluorescein, luminescence was quantified and reflected T cell activation. Fig. 12A. anti-PD-1*1 (■ black), anti-PD-1*1 + isoforms 1IL-7wt 1 (as separate compounds) were added at a series of concentrationsanti-PD-1 x 1il7wt 1 (% black). The right panel shows the calculated EC50 (nM) for each construct. Fig. 12B. anti-PD-1*1 (■ black), anti-PD-1*1 + isoforms IL-7v 1 (as individual compounds) were added at a series of concentrations>anti-PD-1 x 1il7v x 1 (, black). The right panel shows the calculated EC50 (nM) for each construct. Data represent at least 3 independent experiments.

Fig. 13: anti-PD-1*1/IL 7v 1 exhibits higher in vivo pharmacokinetics than anti-PD 1 x 2/IL7v 1 or anti-PD-1*2/IL 7v 2 molecules. A dose (34 nmol/kg) of a bifunctional anti-PD-1/IL-7 v molecule was injected intravenously (FIG. 13A) or intraperitoneally (FIG. 13B) into C57BL/6 mice. Antibody concentrations in serum were quantified at various time points using an anti-human Fc specific ELISA. Left panel, data are presented in nanomolar concentrations. The right panel, the area under the curve for each construct was calculated to define in vivo drug exposure. Data are mean +/-SEM of 2-4 mice/group.

Fig. 14: pharmacokinetic studies of individual anti-PD 1 x 2/IL7 x 1 molecules. The data represent the pharmacokinetics and AUC of each construct of the anti-PD-1/IL-7 molecule constructed with an anti-PD-1*1 or anti-PD-1*2 backbone and one or two fused IL 7. Data are mean +/-SEM of independent experiments containing 1-4 mice/group.

Fig. 15: mouse pharmacokinetic studies after a single injection of anti-PD-1 (anti-PD-1*1 and anti-PD-1*2). C57 BL6 mice were injected with a dose (34 nmol/kg) of anti-PD-1 antibody constructed from monovalent anti-PD-1 (anti-PD-1*1 ■, dotted line) or 2-valent anti-PD-1 (anti-PD-1*2. Cndot. Flat line) (FIG. 15A) for intravenous injection and (FIG. 15B) for intraperitoneal injection. Antibody concentrations in serum were quantified at various time points using an anti-human Fc specific ELISA. Data are presented as nM concentration.

Fig. 16: the anti-PD-1 x 1il7v x 1 molecule significantly promotes T cell proliferation in vivo. Mice were given intraperitoneal injections of one (34 nM/kg) of an anti-PD-1 IL-7v molecule (anti-PD-1X 2IL7v X1, anti-PD-1X 1IL7v X2, anti-PD-1X 2IL7wt 1, anti-PD-1*1 or anti-PD-2). On day 4, tumors and blood were collected and T cells in different T cell subsets were stained with ki67 proliferation markers. The percentage of KI67 in the blood cd3cd4+ and cd3cd8+ populations (fig. 16A) and intratumoral tcf1+ stem cell-like CD 8T cells (CD 45/CD3/CD8/CD 44/tcf1+/TOX-) (fig. 16B) was quantified. Statistical significance (< 0.05) was calculated by the one-way anova test for multiple comparisons with control mice, n=3 to 8 mice per group.

Fig. 17: the anti-PD-1X 1IL 7X 1 molecule has obvious efficacy in an anti-PD-1 drug-resistant liver cancer in-situ model. The experiments used humanized PD-1KI immunocompetent mice. The hepa1.6 hepatoma cells were injected in situ via portal vein. On day 4, mice were treated with 3 doses of PBS (negative control), anti-PD-1*2 and anti-PD-1 x 1il7 x 1. 2 independent experiments were performed. Fig. 17A. Survival of mice treated with anti-PD-1 x 1il7v x 1 relative to anti-PD-1*2 and PBS treated mice. Fig. 17B. Survival of mice treated with anti-PD-1 x 1il7wt x 1 relative to anti-PD-1*2 and PBS treated mice.

Fig. 18: anti-PD-1 x 1il7v x 1 molecules showed high potency in mesothelioma in situ model. The experiments used humanized PD-1KI immunocompetent mice. AK7 mesothelioma cells were injected intraperitoneally. On day 4, mice received 3 doses of PBS (negative control), anti-PD-1*2, anti-PD-1 x 1il7v x 1 treatment. Fig. 18A. Tumor burden was measured by bioluminescence. AK7 cells stably express luciferase and can realize in vivo quantification of bioluminescence. Fig. 18B. Survival rate of mice after treatment.

Fig. 19: the anti-PD-1 x 1IL7v 1 molecule abrogates Treg inhibition function to a greater extent than the IL-7 cytokine alone and the anti-PD-1 x 1IL7wt 1. Cd8+ effector T cells and autologous cd4+cd25high CD127low tregs were isolated from peripheral blood of healthy donors and stained with cell proliferation dye (cd8+ T cells CPDe 670). Treg/cd8+teff was then co-cultured on OKT3 coated plates (2 μg/mL) at a ratio of 1:1 for 5 days with or without rIL-7, anti-PD-1*2, recombinant IL-7 cytokine, anti-PD-1 x 1IL7wt x 1 or anti-PD-1 x 1IL7v x 1 (anti-PD-1 x 1IL7w142 h) (0.12 nM). Proliferation of effector T cells was analyzed by cytofluorimetry based on loss of CPD markers. Data represent% Treg inhibition activity analyzed using formula 100- ((Teff%/Teff proliferation only%)) co-cultured with Treg. Data +/SEM of n=4 independent experimental donors. Statistical significance was one-way analysis of variance using the Dunnett test for multiple comparisons.

Fig. 20: significant long-term single drug therapeutic efficacy of anti-PD-1 x 1il7v x 1 molecules in an anti-PD-1 sensitive in situ model AK7 in situ model. hPD-1KI mice were intraperitoneally injected with AK7 mesothelioma cells and total survival after treatment (a) with PBS (n=8 mice), anti-PD-1*2 (n=8 mice), anti-PD-1 x 1il7v x 1 (W142H x 1) (n=14), anti-PD-1 x 1i l7wt x 1 treatment. Statistical significance was calculated by log rank test (< p < 0.05). (B) anti-PD-1 x 1il7v x 1 induced long-term memory response following tumor re-challenge. Mice cured by anti-PD-1 x 1il7v x 1 treatment (n=7) were re-challenged with AK7 mesothelioma cells (3 e6 cells) by intraperitoneal injection. As a control, a group of initial mice (n=3) was also injected to verify tumor burden and growth. The figure shows luciferase-transduced AK7 tumor cell growth (mean +/-SEM) quantified by bioluminescence following intraperitoneal injection of D-luciferin (150 mg/kg and analysis using a bioanalyzer).

Fig. 21: preclinical efficacy of anti-PD-1 x 1il7v x 1 molecules in an in situ model of liver cancer. Following Hepa 1.6 tumor inoculation, mice were treated with PBS, anti-PD-1 x 1il7v x 1 (anti-PD-1 x 1il7w142h x 1) or anti-PD-1 x 1il7wt x 1 on days 4/6 and 8. Total survival for 3 independent experiments was obtained and described in combination. PBS (n=23); anti-PD-1*2 (n=26), isoform IL-7 (n=14), anti-PD-1 x 1IL7v 1 (n=20) and anti-PD-1 x 1i 7wt 1 (n=19). Statistical significance p <0.05 was calculated using Log Rank test.

Fig. 22: the in vivo gene profile following treatment with anti-PD-1 x 1il7v x 1 molecules showed an increase in stem cell-like memory CD 8T cell subpopulations in the tumor microenvironment. Following Hepa1.6 tumor inoculation, mice were treated with PBS, anti-PD-1 (34.3 nmol/kg) or anti-PD-1 x 1il7v 1 or anti-PD-1 x 1il7wt 1 (34.3 nmol/kg) on days 4/6 and 8 (n=4 per group). Tumors were collected on day 10 and analyzed using Nanostring Pancancer immune panels for heat map representation of gene expression (a) between PBS, anti-PD-1 and anti-PD-1 x 1IL7v x 1 groups, and STRING protein-protein network analysis of common up-regulated genes between anti-PD-1 and BICKI IL7v treatments; (B and C) enrichment of early activated T cells with respect to the genetic profile of depleted T cells. Gene signatures for depleted T cells and for naive/stem cell-like memory T cell signatures were adapted from Andreatta et al (Nature comm2021,12,2965) naive/stem cell-like memory T cells (TCF 7, CCR7, SELL, IL 7R) and depleted CD 8T cell scores (LAG 3, PRF1, CD8A, HAVRC2, GZMB, CD8B1, KLRD1, TNFRSF9, TIGIT, CTSW, CCL4, CD63, IFNG, CXCR6, FASL, CSF 1).

Fig. 23: the anti-PD-1 x 1il7v x 1 molecules induce proliferation of stem cell-like memory CD 8T cell (tcf1+) sub-populations into the tumor microenvironment. (A, B and C) following Hepa1.6 tumor inoculation, mice were treated with PBS, anti-PD-1 (34.3 nmol/kg) or anti-PD-1 x 1il7v x 1 or anti-PD-1 x 1il7wt x 1 (34.3 nmol/kg) on days 4/6 and 8 (n=4 per group). On day 10, tumor T cells were collected and stained for flow cytometry analysis of CD3/CD8/CD44 markers and expression of TCF1/TOX factors. (A) percentage of CD4, CD8 and Treg subpopulations entering the tumor microenvironment (B) percentage of CD44+CD8+ activated T cells expressing TCF1+/-TOX marker (C) proliferation of CD44+CD8+ activated T cells expressing TCF1+/-TOX marker, measured by percentage measurement of KI67 marker in the Hepa1.6 model (D) MC38 subcutaneous model, proliferation of CD44+CD8+ activated T cells expressing TCF1+/-TOX marker measured by percentage of KI67 marker after treatment (anti-PD-1*2 anti-PD-1X 7v X1 (W142H X1))

Fig. 24: anti-PD-1 x 1il7v x 1 maintains survival of long-term stimulated T cells (a) and induces in vitro proliferation of stem cell-like T cells (B). Human PBMCs isolated from peripheral blood of two healthy volunteers were chronically stimulated every three days with anti-CD 3 and anti-CD 28 agonist antibodies. T cells were treated with anti-PD-1, human IL-7 and anti-PD-1 x 1IL7v x 1 during each stimulation period. One day after the 5 th stimulation, T cells were stained with reactive dyes, anti-CD 3, anti-CD 8, anti-TCF 1 and anti-ki 67 proliferation markers. (A) quantifying the viability of the total cells. (B) The percentage of KI67 in the cd3+cd8+tcf1-/+ population was quantified. Data mean +/-SD N = 2 donors per group.

Fig. 25: monotherapy efficacy of anti-PD-1 x 1il7v x 1 molecules in a breast cancer cell humanized mouse model. NXG immunodeficient mice were subcutaneously injected with MDA-MB231 breast cancer cells (3 e6 cells), humanized with human PBMC (3 e6 cells) intraperitoneally on day 8, and then treated intraperitoneally on days 12, 15, and 18 post tumor inoculation with PBS, anti-PD-1*2, or anti-PD-1 x 1IL7v x 1 injections. Mean data +/-SEM N = 3 to 4 mice per group and donor.

Fig. 26: single drug treatment efficacy of anti-PD-1 x 1il7v x 1 molecules in lung cancer a549 humanized mouse pattern. NXG immunodeficient mice were subcutaneously injected with a549 lung cancer cells, humanized by intraperitoneal injection of human PBMC on day 21 (10 e6 cells), and then treated by intraperitoneal injection with PBS, anti-PD-1*2, or anti-PD-1 x 7v x 1 on days 25, 28, 31, and 34 post tumor inoculation. (A) A549 tumor growth n = 5 mice per group, mean +/-SEM. Statistical significance p <0.05 was calculated by comparing anti-PD-1 x 1il7v x 1 group versus anti-PD-1*2 group using Dunnett multiple comparison test. (B) Human IFNg secretion was quantified by ELISA in mouse serum collected on day 35 (n=2-5 mice per group).

Fig. 27 shows that anti-PD-1 x 1il7v x 1 exhibits better pharmacokinetic profile and induces CD 8T cell proliferation in vivo compared to anti-PD-1 x 1i 7wt 1 molecules. Animals were intravenously injected with one dose of anti-PD-1 x 1il-7v x 1 (anti-PD-1 x 1il7w 142h x 1) or anti-PD-1 x 1il7wt 1.8 mg/kg (n=1 cyno), 4.01mg/kg (n=1 cyno), 25mg/kg (n=1 cyno) (a) and the drug concentration in the serum of the animals was quantified by MSD immunoassay. (B) CD 8T cell proliferation measurements in peripheral blood T cells were assessed by flow cytometry after injection of different doses of anti-PD-1 x 1il7v x 1 antibody. (n=1 cyno per dose).

Fig. 28 anti-PD-1 x 1il7v x 1 constructed with either IgG 1N 297A isotype or IgG 1N 297A LALA PG isotype showed similar efficacy in activating pSTAT 5. Stimulated human PBMC were treated with different doses of anti-PD-1 x 1il7v x 1 constructed with IgG 1N 297A isotype or IgG1 LALA P329G mutation. IL-7R signaling activation was measured by intracellular pSTAT5 staining of CD4 and CD 8T cells and analyzed by flow cytometry.

Fig. 29: the anti-PD-1 IL7W 142H mutant exhibited high binding efficiency to PD-1. PD-1 binding ELISA assay. Human recombinant PD-1 (rPD 1) protein was immobilized and antibodies were added at different concentrations. The use of an anti-human Fc antibody conjugated to peroxidase was revealed. Colorimetric assays were performed at 450nm using TMB substrate. Bifunctional molecules comprising the IL7W 142HN297A variant and 1 anti-PD-1 arm (, diamond-solid) were tested as controls. Bifunctional molecules comprising IL7 variants and 1 anti-PD-1 arm (IL 7W 142HN297A DHS ■), (IL 7W 142H N A LS profile), (IL 7W 142H N297AYTE X), (IL 7W 142H N A VL CNDOwt), (IL 7W 142H N297AVL vAv3-11 ∈) were also tested.

Fig. 30: the anti-PD-1 IL7 molecules constructed with monovalent anti-PD-1 and one IL-7W142H mutant cytokine activated pSTAT5 with high efficiency. pSTAT5 signaling assays were performed using the anti-PD-1*1 backbone fused to an IL-7w142h x 1 cytokine mutant. Human T lymphocytes isolated from peripheral blood of healthy volunteers were incubated with bifunctional molecules for 15 min. Cells were then fixed, permeabilized and stained with anti-CD 3-BV421 and anti-pSTAT 5 AF647 (clone 47/Stat5 (pY 694)). Data were obtained by calculating MFI% pstat5+ cells in cd3+ populations. Will contain IL 7W142H N297A variants and 1 anti-PD-1 arms (black diamond-back) and wild-type IL7And the bifunctional molecule against PD-1 molecule (o) constructed from monovalent anti-PD-1 as a control. Bifunctional molecules comprising IL7 variants and 1 anti-PD-1 arm (IL 7W142H N297A DHS (grey ■)), (IL 7W142H N297A LS (black.), (IL 7W142H N297A YTE (black X)), (IL 7W142H N297A VL cndotwt black.), (IL 7W142H N297AVL vAv3-11 grey·) were also tested. />

Detailed Description

Introduction to the invention

The present invention relates to bifunctional molecules having a specific scaffold and comprising a single monovalent antigen binding domain that binds to a target specifically expressed on the surface of an immune cell, in particular PD-1, and a single immunostimulatory cytokine, in particular IL-7. The scaffold consists essentially of a dimeric Fc domain, a single monovalent anti-PD-1 antigen binding domain linked N-terminal to one monomer of the Fc domain, and a single immunostimulatory cytokine (particularly IL-7) linked C-terminal to the Fc domain monomer or light chain (when the antigen binding domain comprises a heavy chain variable chain and a light chain variable chain). These novel bifunctional molecules have, among other advantages, improved pharmacokinetic profiles and better productivity.

The inventors surprisingly show that constructs comprising a single IL-7 variant have improved properties in terms of both activity and pharmacokinetics compared to constructs comprising two IL7 variants.

Definition of the definition

For easier understanding of the present invention, certain terms are defined below. Additional definitions are set forth throughout the detailed description.

Unless otherwise defined, all technical, symbolic and other scientific terms used herein are intended to have the meaning commonly understood by one of ordinary skill in the art to which this invention belongs. In some cases, terms with commonly understood meanings are defined herein for clarity and/or ease of reference, and inclusion of such definitions herein should not necessarily be construed to represent a difference from what is commonly understood in the art. The techniques and procedures described or referenced herein are generally well understood by those skilled in the art and are generally employed using conventional methods.

The terms "wild-type interleukin-7", "wt-IL-7" and "wt-IL7" as used herein refer to mammalian endogenous secreted glycoproteins, particularly IL-7 polypeptides, derivatives and analogs thereof, which have substantially the same amino acid sequence and substantially equivalent biological activity as wild-type functional mammalian IL-7, e.g., in a standard bioassay or IL-7 receptor binding affinity assay. For example, wt-IL-7 refers to the amino acid sequence of a recombinant or non-recombinant polypeptide having the amino acid sequence: i) Naturally occurring or naturally occurring IL-7 polypeptide, ii) a biologically active fragment of an IL-7 polypeptide, iii) a biologically active polypeptide analog of an IL-7 polypeptide, or iv) a biologically active IL-7 polypeptide. IL-7 may contain its peptide signal or be free of its peptide signal. Alternative names for this molecule are "pre-B cell growth factor" and "lymphopoietin-1". Preferably, the term "wt-IL-7" refers to human IL-7 (wth-IL 7). For example, human wt-IL-7 has an amino acid sequence of about 152 amino acids (no signal peptide present) and has Genbank accession number NP-000871.1, which is located on chromosome 8q 12-13. Human IL-7 is described, for example, in UniProtKB-P13232. As used herein, the terms "programmed death 1", "programmed cell death 1", "PD-1", "PDCD1", "PD-1 antigen", "human PD-1", "hPD-1" and "hPD1" are used interchangeably and refer to the programmed death-1 receptor, also known as CD279, and include variants of human PD-1 and analogs having at least one epitope in common with PD-1. PD-1 is a key regulator of the threshold of immune response and peripheral immune tolerance. It is expressed on activated T cells, B cells, monocytes and dendritic cells and binds to its ligands PD-L1 and PD-L2. Human PD-1 is encoded by the PDCD1 gene. As an example, the amino acid sequence of human PD-1 is disclosed under GenBank accession No. np_ 005009. PD1 has four splice variants expressed on human Peripheral Blood Mononuclear Cells (PBMC). Thus, PD-1 proteins include full-length PD-1, as well as alternative splice variants of PD-1, such as PD-1Aex2, PD-1Aex3, PD-1Aex2,3 and PD-1Aex2,3,4. Unless otherwise indicated, these terms include any variant or subtype of human PD-1 that is naturally expressed by PBMCs or expressed by cells transfected with the PD-1 gene.

As used herein, the term "antibody" describes and is used in its broadest sense to describe a class of immunoglobulin molecules. In particular, antibodies include immunoglobulin molecules and immunologically active fragments of immunoglobulin molecules, i.e., molecules that contain an antigen binding site. Immunoglobulin molecules may be of any type (e.g., igG, igE, igM, igD, igA and IgY), class (e.g., igGl, igG2, igG3, igG4, igA1, and IgA 2) or subclass. The heavy chain constant domains corresponding to the different classes of immunoglobulins are called α, δ, ε, γ and mu, respectively. Unless specifically stated otherwise, the term "antibody" includes intact immunoglobulins and "antibody fragments" or "antigen-binding fragments" (e.g., fab ', F (ab') 2, fv), single chains (scFv), mutants thereof, molecules comprising an antibody moiety, diabodies, linear antibodies, single chain antibodies, and any other modified configuration of an immunoglobulin molecule comprising an antigen recognition site of the desired specificity, including glycosylated variants of antibodies, amino acid sequence variants of antibodies. Preferably, the term antibody refers to a humanized antibody.

As used herein, "antibody heavy chain" refers to the larger of the two types of polypeptide chains that exist in an antibody conformation. The CDRs of antibody heavy chains are commonly referred to as "HCDR1", "HCDR2" and "HCDR3". The framework regions of the antibody heavy chain are commonly referred to as "HFR1", "HFR2", "HFR3" and "HFR4".

As used herein, "antibody light chain" refers to the smaller of two types of polypeptide chains that exist in an antibody conformation; kappa and lambda light chains refer to two major antibody light chain isotypes. CDRs of an antibody light chain are commonly referred to as "LCDR1", "LCDR2", and "LCDR3". The framework regions of antibody light chains are commonly referred to as "LFR1", "LFR2", "LFR3", and "LFR4".

As used herein, an "antigen binding fragment" or "antigen binding domain" of an antibody means a portion of an antibody, i.e., a molecule corresponding to a portion of the structure of an antibody of the invention, which exhibits antigen binding capacity against a particular antigen, possibly in its native form; such fragments in particular exhibit the same or substantially the same antigen binding specificity for the antigen as compared to the antigen binding specificity of the corresponding four-chain antibody. Advantageously, the antigen binding fragment has a binding affinity similar to that of the corresponding 4-chain antibody. However, antigen binding fragments having reduced antigen binding affinity relative to corresponding 4-chain antibodies are also encompassed within the invention. The antigen binding capacity can be determined by measuring the affinity between the antibody and the target fragment. These antigen binding fragments may also be referred to as "functional fragments" of antibodies. An antigen binding fragment of an antibody is a fragment comprising its hypervariable domains, called CDRs (complementarity determining regions), or parts thereof.

As used herein, the term "humanized antibody" means an antibody in which CDR sequences derived from the germline of another mammalian species (e.g., mouse) have been grafted onto human framework sequences (e.g., chimeric antibodies containing minimal sequences derived from non-human antibodies). "humanized form" of an antibody, such as a non-human antibody, also refers to an antibody that has undergone humanization. Humanized antibodies are typically human immunoglobulins (recipient antibody) in which residues from one or more CDRs are replaced by residues from at least one CDR of a non-human antibody (donor antibody) while maintaining the desired specificity, affinity and capacity of the original antibody. Additional framework region modifications may be made within the human framework sequence. Preferably, the humanized antibody has a T20 humanized score of greater than 80%, 85% or 90%. The "humanization" of an antibody can be measured, for example, using a T20 score analyzer to quantify the humanization of the antibody variable region, such as Gao SH, huang K, tu H, adler a s.bmc Biotechnology 2013: the T20 score for the antibody sequence was calculated using the T20 cutoff human database as described in 13:55 or by a web-based tool: http:// abanalyzer.lakepharma.com.

"chimeric antibody" refers to an antibody prepared by combining genetic material from a non-human source (preferably, e.g., mice) with genetic material from a human. Such antibodies are derived from human and non-human antibodies linked by chimeric regions. Chimeric antibodies typically comprise a constant domain from a human and a variable domain from another mammalian species, which when used in therapeutic treatment, reduce the risk of reacting to exogenous antibodies from non-human animals.

As used herein, the terms "fragment crystallizable region", "Fc region" or "Fc domain" are interchangeable and refer to the tail region of an antibody that interacts with a cell surface receptor called an Fc receptor. The Fc region or domain typically consists of two domains, optionally identical, the second and third constant domains (i.e., CH2 and CH3 domains) derived from the two heavy chains of an antibody. A portion of an Fc domain refers to a CH2 or CH3 domain. Optionally, the Fc region or domain may optionally comprise all or a portion of the hinge region between CH1 and CH 2. Accordingly, an Fc domain may comprise a hinge, a CH2 domain, and a CH3 domain. Optionally, the Fc domain is an Fc domain from IgGl, igG2, igG3 or IgG4, optionally with IgGl hinge-CH 2-CH3 and IgG4 hinge-CH 2-CH3.

In the context of IgG antibodies, each IgG isotype has three CH regions. Thus, the "CH" domain in the IgG context is as follows: "CH1" refers to positions 118-215 according to the EU index in Kabat. "hinge" refers to positions 216-230 according to the EU index in Kabat. "CH2" refers to positions 231-340 according to the EU index in Kabat, and "CH3" refers to positions 341-447 according to the EU index in Kabat.

"amino acid change" or "amino acid modification" herein means a change in the amino acid sequence of a polypeptide. "amino acid modifications" include substitutions, insertions and/or deletions in the polypeptide sequence. "amino acid substitution" or "substitution" herein refers to the replacement of an amino acid at a particular position in a parent polypeptide sequence with another amino acid. "amino acid insertion" or "insertion" refers to the addition of an amino acid at a particular position in a parent polypeptide sequence. "amino acid deletion" or "deletion" refers to the removal of an amino acid at a particular position in a parent polypeptide sequence. Amino acid substitutions may be conservative. A conservative substitution is the replacement of a given amino acid residue with another residue of a side chain ("R group") having similar chemical properties (e.g., charge, volume, and/or hydrophobicity). As used herein, "amino acid position" or "amino acid position number" are used interchangeably to refer to the position of a particular amino acid in an amino acid sequence, typically designated by a single letter code for the amino acid. The first amino acid in the amino acid sequence (i.e. starting from the N-terminus) should be considered as having position 1.

A conservative substitution is the replacement of a given amino acid residue with another residue of a side chain ("R group") having similar chemical properties (e.g., charge, volume, and/or hydrophobicity). Generally, conservative amino acid substitutions do not significantly alter the functional properties of the protein. Conservative substitutions and corresponding rules are well described in the prior art. For example, conservative substitutions may be defined by substitutions within the group of amino acids reflected in the following table:

TABLE A amino acid residues

Amino acid group	Amino acid residues
		Acidic residues	ASP and GLU
Basic residues	LYS, ARG, and HIS
		Hydrophilic uncharged residues	SER, THR, ASN, and GLN
Aliphatic uncharged residues	GLY, ALA, VAL, LEU, and ILE
		Nonpolar uncharged residues	CYS, MET, and PRO
Aromatic residues	PHE, TYR, and TRP

TABLE B substitution of conservative amino acid residue substitutions

1	Alanine (A)	Serine (S)	Threonine (T)
				2	Aspartic acid (D)	Glutamic acid (E)
3	Asparagine (N)	Glutamine (Q)
				4	Arginine (R)	Lysine (K)
5	Isoleucine (I)	Leucine (L)	Methionine (M)
				6	Phenylalanine (F)	Tyrosine (Y)	Tryptophan (W)

Further substitution of Table C-amino acid residues physical and functional classifications

Residues containing alcohol groups	S and T
		Aliphatic residues	I, L, V, and M
Cycloalkenyl-related residues	F, H, W, and Y
		Hydrophobic residues	A, C, F, G, H, I, L, M, R, T, V, W, and Y
Negatively charged residues	D and E
		Polar residues	C, D, E, H, K, N, Q, R, S, and T
Small residues	A, C, D, G, N, P, S, T, and V
		Very small residues	A, G, and S
Residues involved in corner formation	A, C, D, E, G, H, K, N, Q, R, S, P, and T
		Elastic residue	E, Q, T, K, S, G, P, D, E, and R

As used herein, "sequence identity" between two sequences is described by the parameters "sequence identity", "sequence similarity" or "sequence homology". For the purposes of the present invention, the "percent identity" between two sequences (A) and (B) is determined by comparing the two sequences optimally aligned by comparison windows. The sequence alignment may be performed by methods well known in the art, for example using the Needleman-Wunsch global alignment algorithm. Protein analysis software uses similarity measurements assigned to various substitutions, deletions, and other modifications (including conservative amino acid substitutions) to match similar sequences. Once the total alignment is obtained, the percent identity can be obtained by dividing the total number of identical amino acid residues aligned by the total number of residues contained in the longest sequence between sequences (a) and (B). Sequence identity is typically determined using sequence analysis software. To compare two amino acid sequences, a pair-wise sequence alignment of the proteins provided by EMBL-EBI can be performed using the "Emboss Needle" tool, which is available on the following website: www.ebi.ac.uk/Tools/services/web/tools=ebit_needle & context=protein, e.g. using default settings: (I) matrix: BLOSUM62, (ii) gap open: 10, (iii) gap extension: 0.5, (iv) output format: for (v) end gap penalty: pseudo, (vi) end gap open: 10, (vii) end gap extension: 0.5.

Alternatively, sequence identity can also be determined using the sequence analysis software Clustal Omega, typically using the HHALIgn algorithm and its default settings as its core alignment engine. At the position ofJ. (2005) The algorithm is described in 'Protein homology detection by HMM-HMM compactison' Bioinformatics 21,951-960, using default settings.

The term "derived from" as used herein refers to a compound having a structure derived from the structure of the parent compound or protein, and whose structure is sufficiently similar to those disclosed herein, and based on that similarity, one skilled in the art would expect to exhibit the same or similar properties, activity and utility as the claimed compounds.

As used herein, "pharmaceutical composition" refers to a formulation of one or more active agents (e.g., comprising a bifunctional molecule according to the invention) with optionally other chemical components (e.g., physiologically suitable carriers and excipients). The purpose of the pharmaceutical composition is to facilitate the administration of the active agent to the organism. The compositions of the present invention may be in a form suitable for any conventional route of administration or use. In one aspect, "composition" generally means a combination of an active agent (e.g., a compound or composition) and a naturally occurring or non-naturally occurring carrier, an inert (e.g., a detectable agent or label), or an active carrier (e.g., an adjuvant, diluent, binder, stabilizer, buffer, salt, lipophilic solvent, preservative, adjuvant, etc.), and includes pharmaceutically acceptable carriers. Reference herein to an "acceptable excipient" or "acceptable carrier" is to any known compound or combination of compounds known to those skilled in the art to be useful in formulating pharmaceutical compositions.

As used herein, "effective amount" or "therapeutically effective amount" refers to the amount of active agent required to impart a therapeutic effect to a subject, e.g., to treat a disease or disorder of interest or to produce a desired effect, alone or in combination with one or more other active agents. The "effective amount" will vary depending upon the agent, the disease and its severity, the characteristics of the subject to be treated (including age, physical condition, size, sex and weight), the duration of the treatment, the nature of concurrent therapy (if any), the particular route of administration, and similar factors within the knowledge and expertise of the health practitioner. These factors are well known to those of ordinary skill in the art and can be addressed by routine experimentation only. It is generally preferred to use the maximum dose of the individual components or combinations thereof, i.e. the highest safe dose according to sound medical judgment.

As used herein, the term "drug" refers to any substance or composition that has therapeutic or prophylactic properties against a disorder or disease.

The term "treatment" refers to any action intended to improve the health of a patient, such as the treatment, prevention, prophylaxis and delay of a disease or disease symptoms. It refers to curative and/or prophylactic treatment of a disease. Curative treatment is defined as treatment that results in cure or treatment that reduces, ameliorates and/or eliminates, reduces and/or stabilizes a disease or symptoms of a disease or pain caused directly or indirectly by it. Prophylactic treatment includes treatment that results in the prevention of a disease and treatment that reduces and/or delays the progression and/or incidence of a disease or the risk of developing the same. In certain aspects, such terms refer to the amelioration or eradication of a disease, disorder, infection, or symptom associated therewith. In other aspects, the term refers to minimizing the spread or exacerbation of cancer. Treatment according to the present invention does not necessarily mean 100% or complete treatment. Rather, there are varying degrees of treatment that one of ordinary skill in the art would consider to have potential benefits or therapeutic effects. Preferably, the term "treatment" refers to administration or administration of a composition comprising one or more active agents to a subject suffering from a disorder/disease.

The term "disorder" or "disease" as used herein refers to an organ, portion, structure or system that is not functioning properly due to genetic or developmental errors, infection, poisoning, nutritional deficiency or imbalance, toxicity or the effects of adverse environmental factors. Preferably, these terms refer to a health disorder or disease, such as a health disorder or disease, e.g., a disease that disrupts normal body or mental function. More preferably, the term disorder refers to an immune and/or inflammatory disease affecting animals and/or humans, such as cancer.

As used herein, "immune cells" refers to cells involved in innate and adaptive immunity, such as leukocytes (leukocytes), lymphocytes (T cells, B cells, natural Killer (NK) cells, and natural killer T cells (NKT)) and bone marrow-derived cells (neutrophils, eosinophils, basophils, monocytes, macrophages, dendritic cells) derived from Hematopoietic Stem Cells (HSCs) produced in the bone marrow. In particular, the immune cells may be selected from a non-exhaustive list comprising B cells, T cells, in particular cd4+ T cells and cd8+ T cells, NK cells, NKT cells, APC cells, dendritic cells and monocytes. "T-cells" as used herein include, for example, CD4+ T-cells, CD8+ T-cells, T-helper type 1T-cells, T-helper type 2T-cells, T-helper type 17T-cells, and suppressor T-cells.

As used herein, the term "effector T cell", "T eff" or "effector cell" describes a group of immune cells that includes several T cell types that actively respond to a stimulus (e.g., co-stimulus). It includes in particular T cells with an antigen-eliminating function (for example by producing cytokines that regulate the activation of other cells or by cytotoxic activity). It includes in particular cd4+, cd8+, cytotoxic T cells and helper T cells (Th 1 and Th 2).

As used herein, the term "regulatory T cells", "Treg cells" or "T regs" refers to a subpopulation of T cells that regulate the immune system, maintain tolerance to self-antigens, and prevent autoimmune diseases. Tregs have immunosuppressive effects, often inhibiting or down regulating the induction and proliferation of effector T cells. Tregs express the biomarkers CD4, FOXP3 and CD25 and are believed to be derived from the same lineage as the original CD4 cells.

The term "depleted T cells" refers to a population of T cells that are in a dysfunctional state (i.e., "depleted"). T cell depletion is characterized by progressive loss of function, changes in transcriptional profile, and sustained expression of inhibitory receptors. Depleted T cells lose cytokine production, high proliferation capacity and cytotoxic potential, ultimately leading to their depletion. Depleted T cells generally indicate higher levels of CD43, CD69 and inhibitory receptors, while CD62L and CD127 are expressed less.

The term "effector memory stem cell-like T cells" refers to a subset of T cells within a tumor-reactive tumor that have the characteristics of depleting cells and central memory cells, including the expression of checkpoint protein PD-1 and transcription factor Tcf 1. These cells may be referred to as tcf1+pd-1+cd8+t cells. These cells are present in the tumor microenvironment and are critical to the immune control of the cancer that is facilitated by the immunotherapy. They are critical for maintaining T cell responses during chronic viral infection and cancer and provide a proliferation burst following PD-1 immunotherapy. These cells undergo slow self-renewal and produce more terminally differentiated depleted CD 8T cells. These cells and their characteristics are further defined in the following articles, the disclosures of which are incorporated herein by reference: siddiqui et al,2019, immunity,50,195-211; and Jadhav et al,2019, PNAS,116, 14113-14118).

The term "immune response" refers to the action of, for example, lymphocytes, antigen presenting cells, phagocytes, granulocytes, and soluble macromolecules produced by such cells or liver, including antibodies, cytokines, and complement, which result in selective damage, destruction, or elimination of an invading pathogen, pathogen-infected cell or tissue, cancer cell, or normal human cell or tissue in the case of autoimmune or pathological inflammation.

The term "antagonist" as used herein refers to a substance that blocks or reduces the activity or function of another substance. In particular, the term refers to antibodies that bind to a cellular receptor (e.g., PD-1) as a reference substance (e.g., PD-L1 and/or PD-L2) preventing it from producing all or part of its usual biological effects (e.g., creating an immunosuppressive microenvironment). The antagonist activity of the humanized antibodies according to the present invention can be assessed by competitive ELISA.

The term "agonist" as used herein refers to a substance that activates the function of an activating receptor. In particular, the term refers to antibodies that bind to a cell-activating receptor as a reference substance and have at least partially the same effect as a biological natural ligand (e.g., an activator effect of the inducing receptor).

Pharmacokinetic (PK) refers to the movement of a drug in the body, while Pharmacodynamics (PD) refers to the biological response of the body to a drug. PK describes drug exposure by characterizing absorption, distribution, bioavailability, metabolism, and excretion as a function of time. PD describes drug reactions using biochemical or molecular interactions. PK and PD analysis was used to characterize drug exposure, predict and evaluate dose variation, estimate elimination rate and absorption rate, evaluate relative bioavailability/bioequivalence of formulation, characterize intra-and inter-subject variability, understand concentration effect relationships, and establish safety margin and efficacy profile. "improving PK" means an improvement in one of the above characteristics, such as an increase in the half-life of the molecule, particularly a longer serum half-life of the molecule when injected into a subject.

As used herein, the terms "pharmacokinetic" and "PK" are used interchangeably to refer to the fate of a compound, substance, or drug administered to a living organism. Pharmacokinetics include, inter alia, ADME or LADME protocols, which represent release (i.e., release of a substance from a composition), absorption (i.e., entry of a substance into the blood circulation), distribution (i.e., dispersion or propagation of a substance in the body), metabolism (i.e., conversion or degradation of a substance), and excretion (i.e., removal or clearance of a substance from an organism). The two stages of metabolism and excretion can also be grouped into one category, called elimination. One skilled in the art can monitor various pharmacokinetic parameters such as elimination half-life, elimination constant rate, clearance (i.e. the volume of plasma cleared of drug per unit time), cmax (maximum serum concentration) and drug exposure (as measured by area under the curve, see Scheff et al, pharm Res.201mmay; 28 (5): 1081-9), etc.

As used herein, the term "isolated" means that the recited material (e.g., antibody, polypeptide, nucleic acid, etc.) is substantially separated from, or enriched relative to, other materials with which it naturally occurs. In particular, an "isolated" antibody is an antibody that has been identified and isolated and/or recovered from a component of its natural environment.

The term "and/or" as used herein is to be taken as a specific disclosure of each of the two specified features or components with or without the other. For example, "a and/or B" should be considered as a specific disclosure of each of (i) a, (ii) B, and (iii) a and B, as if each were individually listed.

The term "a/an" may refer to one or more elements (e.g., "an agent" may refer to one or more agents) to which it is modified, unless the context clearly describes one or more of the elements.

The term "about" as used herein in connection with any and all values (including the lower and upper ends of a range of values) means any value having an acceptable deviation range of up to +/-10% (e.g., +/-0.5%, +/-1%, +/-1.5%, +/-2%, +/-2.5%, +/-3%, +/-3.5%, +/-4%, +/-4.5%, +/-5%, +/-5.5%, +/-6%, +/-6.5%, +/-7%, +/-7.5%, +/-8%, +/-8.5%, +/-9%, +/-9.5%). Use of the term "about" at the beginning of a string of values modifies each value (i.e., "about 1, 2, and 3" means about 1, about 2, and about 3). Further, when a list of values is described herein (e.g., about 50%, 60%, 70%, 80%, 85%, or 86%), the list includes all intermediate values and fractional values thereof (e.g., 54%, 85.4%).

The term "substantially" as used herein in relation to any given biological sequence means that the biological sequence differs from the reference sequence comprised in the sequence listing by up to 10% of the length of the biological sequence. In particular, "consisting essentially of" means that the biological sequence consists of the sequence, but it may also comprise 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 substitutions, additions, deletions or mixtures thereof, preferably 1, 2, 3, 4 or 5 substitutions, additions, deletions or mixtures thereof, provided that the biological sequence differs from the reference sequence comprised in the sequence listing by at most 10% of the length of the biological sequence.

Bifunctional molecules

The present invention relates to bifunctional molecules having scaffolds associated with improved properties.

More specifically, the invention relates to bifunctional molecules having a specific scaffold and comprising a single monovalent antigen binding domain that binds to PD-1 and a single IL-7m. The stent consists essentially of: a dimeric Fc domain, a single monovalent antigen binding domain that binds PD-1 linked N-terminally to one monomer of the Fc domain, and i) a single IL-7m and optionally a peptide linker linked C-terminally to the same monomer of the Fc domain, or ii) a single monovalent antigen binding domain comprising a heavy chain variable chain and a light chain variable chain and a single IL-7m linked C-terminally to the light chain of the antigen binding domain.

In a specific aspect, the bifunctional molecule comprises a first monomer comprising an anti-PD-1 antigen-binding domain covalently linked to a first Fc chain, optionally via a peptide linker, optionally covalently linked to IL-7m via a peptide linker, and a second monomer comprising an antigen-binding domain-free and a complementary second Fc chain free of IL-7m, said first and second Fc chains forming a dimeric Fc domain.

In another aspect, the bifunctional molecule comprises a first monomer comprising an anti-PD-1 antigen-binding domain covalently linked to a first Fc chain, optionally via a peptide linker, and a second monomer comprising an antigen-binding domain-free and a second Fc chain free of complementarity to IL-7m, the first and second Fc chains forming a dimeric Fc domain, and a single monovalent antigen-binding domain comprising a heavy chain variable chain and a light chain variable chain, and a single IL-7m linked at the C-terminus of the light chain of the antigen-binding domain.

Thus, the two monomers each comprise an Fc chain capable of forming a dimeric Fc domain. In one aspect, the dimeric Fc fusion protein is a homodimeric Fc domain. In another aspect, the dimeric Fc fusion protein is a heterodimeric Fc domain.

More specifically, when the dimeric Fc domain is a heterodimeric Fc domain, the bifunctional molecule comprises a first monomer comprising an antigen binding domain covalently linked to the N-terminus of a first heterodimeric Fc chain, optionally via a peptide linker, which is covalently linked to IL-7m via its C-terminus; the second monomer comprises a complementary second heterodimeric Fc chain that is free of an antigen binding domain and free of IL-7 m. Optionally, the second monomer comprising a complementary second heterodimeric Fc strand lacks any other functional moiety, in particular another antigen binding domain or any cytokine. Still more particularly, the bifunctional molecule comprises a first monomer comprising an antigen binding domain covalently linked via a peptide linker to the N-terminus of a first heterodimeric Fc chain covalently linked via its C-terminus to the N-terminus of IL-7m, optionally via a peptide linker; the second monomer comprises an antigen binding domain-free and an IL-7 m-free complementary second heterodimeric Fc chain, preferably free of any other functional moiety, in particular another antigen binding domain or any cytokine. Such a bifunctional molecule is illustrated, for example, in FIG. 1 as "construct 3", wherein IL-7W142H is illustrated as IL-7 m.

Optionally, the single antigen binding domain is selected from Fab, fab', scFV, and sdAb.

Thus, in one aspect, the bifunctional molecule according to the invention comprises or consists of:

(a) An anti-PD 1 antigen-binding domain comprising (i) a heavy chain having a first Fc chain, and (ii) a light chain,

(b) IL-7m, and

(c) A second, complementary Fc chain that is complementary to the first Fc chain,

wherein IL-7m is covalently linked to the C-terminus of the first Fc chain, optionally via a peptide linker, preferably via its N-terminus. The first Fc chain and the second Fc chain together form a dimeric Fc domain.

In a specific aspect, the bifunctional molecule comprises:

an antibody heavy chain comprising a VH-CH 1-hinge-CH 2-CH3 linked at its C-terminus to IL-7m,

an antibody light chain comprising a VL-CL (constant light chain), a VH-CH1 part and a VL-CL part together forming an antigen-binding domain that binds PD-1, in particular expressed on the surface of immune cells, and

-an Fc chain comprising CH2-CH3, optionally hinge-CH 2-CH3, forming a dimeric Fc domain with CH2-CH3 of the antibody heavy chain.

According to an alternative aspect, when the dimeric Fc domain is a heterodimeric Fc domain, the bifunctional molecule comprises a first monomer comprising an antigen binding domain covalently linked to the N-terminus of the first heterodimeric Fc chain, optionally via a peptide linker, and a second monomer comprising an antigen binding domain free and a complementary second heterodimeric Fc chain free of IL-7m, and the antigen binding domain comprises a heavy chain variable chain and a light chain variable chain and IL-7m is optionally linked to the C-terminus of the light chain of the antigen binding domain via a peptide linker. Optionally, the IL-7m is linked at the C-terminus of the light chain of the antigen binding domain, optionally via a peptide linker, through its N-terminus.

Thus, in this aspect, the bifunctional molecule according to the invention comprises or consists of:

(b) IL-7m, and

(c) A second, complementary Fc-chain,

wherein IL-7m is covalently linked to the C-terminus of the light chain, optionally via a peptide linker, preferably via its N-terminus. The first Fc chain and the second Fc chain together form a dimeric Fc domain.

In a specific aspect, the bifunctional molecule comprises:

an antibody heavy chain comprising VH-CH 1-hinge-CH 2-CH3,

an antibody light chain comprising a VL-CL (constant light chain) linked at its C-terminus to IL-7m, a VH-CH1 moiety and a VL-CL moiety together forming an anti-PD-1 antigen-binding domain (specifically binding to PD-1 expressed on the surface of immune cells), and

IL-7m, anti-PD 1 antigen binding domain, fc domain and optionally linker are further defined in any aspect as follows.

IL-7 and IL-7 variants

IL-7m is capable of stimulating or activating immune cells. The immune cells may be selected from a non-exhaustive list comprising: b cells, T cells, in particular cd4+ T cells and cd8+ T cells, NK cells, NKT cells, APC cells, dendritic cells and monocytes. In a preferred aspect, the immune cells are T cells, more specifically cd8+ T cells, effector T cells or depleted T cells. In a particularly preferred aspect, the immune cells are effector memory stem cell-like T cells.

In particular, IL-7m has a size of 10kDa to 50 kDa. Preferably, IL-7m is a peptide, polypeptide or protein. In one aspect, IL-7m is a non-antibody entity or moiety.

IL-7m may be mutated or altered to alter biological activity, e.g., increase, decrease, or complete inhibition of biological activity.

In very specific aspects, IL-7m is IL-7 or a variant thereof, which has at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% identity with a wild-type cytokine, or has 1 to 10 modifications selected from the group consisting of additions, deletions, substitutions and combinations thereof.

In a specific aspect, the IL-7 variant or mutant thereof comprises or consists of SEQ ID NO. 1 or a sequence having at least 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99% identity thereto or a sequence having 1 to 10 modifications relative to the sequence of SEQ ID NO. 1 selected from the group consisting of additions, deletions, substitutions and combinations thereof.

The terms "interleukin-7 mutant", "mutated IL-7", "IL-7 mutant", "IL-7 variant", "IL-7m" or "IL-7v" are used interchangeably herein. A "variant" or "mutant" of an IL-7 protein is defined as an amino acid sequence that is altered by one or more amino acids. The variant may have "conservative" modifications or "non-conservative" modifications. Such modifications may include amino acid substitutions, deletions and/or insertions. Preferably, the modification is a substitution, in particular a conservative substitution. Variant IL-7 proteins encompassed by the present invention are particularly directed to IL-7 proteins that do not retain substantially equivalent biological properties (e.g., activity, binding capacity, and/or structure) as compared to wild-type IL-7. The IL-7 mutant or variant comprises at least one mutation. In particular, at least one mutation reduces the affinity of IL-7m for IL-7R, but does not result in loss of IL-7R recognition. Thus, the IL-7 mutant or variant retains the ability to activate IL-7R, as measured, for example, by pStat5 signaling, e.g., as disclosed by Bitar et al, front.Immunol.,2019, volume 10). The biological activity of IL-7 protein can be measured using an in vitro cell proliferation assay or by measuring P-Stat5 in T cells by ELISA or FACS. Preferably, the IL-7 variants according to the invention have a biological property (e.g. activity, binding capacity and/or structure) that is reduced by at least a factor of 2, 5, 10, 20, 30, 40, 50, 100, 250, 500, 750, 1000, 2500, 5000 or 8000 compared to wild-type IL-7, preferably wth-IL 7. More preferably, the IL-7 variant has reduced binding to the IL-7 receptor, but retains the ability to activate IL-7R. For example, binding to an IL-7 receptor may be reduced by at least 10%, 20%, 30%, 40%, 50%, 60% as compared to wild-type IL-7, and retain at least 90%, 80%, 70%, 60%, 50%, 40%, 30%, or 20% of the ability to activate IL-7R as compared to wild-type IL-7. Preferably, IL-7m is a variant of human wild-type IL-7, such as depicted in SEQ ID NO. 1.

In one aspect, the IL-7 variant according to the invention retains at least 1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, preferably at least 80%, 90%, 95% and even more preferably 99% of the biological activity compared to wild-type human IL-7.

In one aspect, the IL-7 variant or mutant differs from wt-IL-7 by at least one amino acid mutation, i) decreasing the affinity of the IL-7 variant for IL-7 receptor (IL-7R) compared to the affinity of wt-IL-7 for IL-7R, and ii) improving the pharmacokinetics of the IL7 variant compared to wt-IL 7. More specifically, the IL-7 variant or mutant further retains the ability to activate IL-7R, particularly through pStat5 signaling.

In another aspect, a bifunctional molecule comprising an IL-7 variant or mutant differs from wt-IL-7 by at least one amino acid mutation that i) reduces the affinity of the bifunctional molecule for IL-7 receptor (IL-7R) compared to the affinity of the bifunctional molecule comprising wt-IL-7 for IL-7R, and ii) improves the pharmacokinetics of the bifunctional molecule comprising the IL-7 variant or mutant compared to the bifunctional molecule comprising wt-IL-7. More specifically, bifunctional molecules comprising IL-7 variants or mutants further retain the ability to activate IL-7R, particularly through pStat5 signaling. For example, a binding bifunctional molecule comprising an IL-7 variant or mutant to an IL-7 receptor may be reduced by at least 10%, 20%, 30%, 40%, 50%, 60% compared to a bifunctional molecule comprising wild-type IL-7, and retain at least 90%, 80%, 70%, 60%, 50%, 40%, 30% or 20% of the ability to activate IL-7R compared to a bifunctional molecule comprising wild-type IL-7.

According to the invention, the affinity of IL-7m for IL-7 receptor (IL-7R) is reduced compared to the affinity of wth-IL-7 for IL-7R. In particular, IL-7m has a reduced affinity for CD127 and/or CD132 compared to the affinity of wth-IL-7 for CD127 and/or CD132, respectively. Preferably, the affinity of IL-7m for CD127 is reduced compared to the affinity of wth-IL-7 for CD 127.

Preferably, the at least one amino acid mutation reduces the affinity of IL-7m for IL-7R, in particular CD132 or CD127, by at least 10, 100, 1000, 10000 or 100000 times compared to the affinity of wt-IL-7 for IL-7R. Such affinity comparison may be performed by any method known to those skilled in the art, such as ELISA or Biacore.

Preferably, the at least one amino acid mutation reduces the affinity of IL-7m for IL-7R, but does not reduce the biological activity of IL-7m compared to IL-7wt, in particular as measured by pStat5 signaling.

Alternatively, at least one amino acid mutation reduces the affinity of IL-7m for IL-7R, but does not significantly reduce the biological activity of IL-7m compared to IL-7wt, particularly as measured by pStat5 signaling.

Additionally or alternatively, IL-7m improves the pharmacokinetics of IL-7 variants or mutants or bifunctional molecules comprising IL-7 variants, respectively, compared to wild-type IL-7 or bifunctional molecules comprising wild-type IL-7. In particular, IL-7m according to the invention improves the pharmacokinetics of IL-7 variants by at least a factor of 10, 100 or 1000 compared to wth-IL-7. In particular, IL-7m according to the invention improves the pharmacokinetics of a bifunctional molecule comprising an IL-7 variant or mutant by at least a factor of 10, 100 or 1000 compared to a bifunctional molecule comprising IL-7. Pharmacokinetic profile comparison can be performed by any method known to the person skilled in the art, e.g. in vivo injection of a drug and dose ELISA of the drug in serum at multiple time points, e.g. as shown in example 2.

As used herein, the terms "pharmacokinetic" and "PK" are used interchangeably to refer to the fate of a compound, substance, or drug administered to a living organism. Pharmacokinetics include, inter alia, ADME or LADME protocols, which represent release (i.e., release of a substance from a composition), absorption (i.e., entry of a substance into the blood circulation), distribution (i.e., dispersion or propagation of a substance in the body), metabolism (i.e., conversion or degradation of a substance), and excretion (i.e., removal or elimination of a substance from an organism). The two stages of metabolism and excretion can also be grouped into one category, called elimination. One skilled in the art can monitor various pharmacokinetic parameters such as elimination half-life, elimination constant rate, clearance (i.e. the volume of plasma cleared of drug per unit time), cmax (maximum serum concentration) and drug exposure (as measured by area under the curve, see Scheff et al, pharm Res.201mmay; 28 (5): 1081-9), etc.

Improving pharmacokinetics by using IL-7m, in particular a bifunctional molecule, then means an improvement in at least one of the above-mentioned parameters. Preferably, it refers to an improvement in the elimination half-life of the bifunctional molecule, i.e. an increase in half-life duration or Cmax.

In a specific aspect, at least one mutation of IL-7m improves the elimination half-life of a bifunctional molecule comprising IL-7m compared to a bifunctional molecule comprising IL-7 wt.

In one aspect, IL-7m has at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, at least 98%, or at least 99% identity to a 152 amino acid wild-type human IL-7 (wth-IL-7) protein, such as disclosed in SEQ ID NO: 1. Preferably, IL-7m exhibits at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 97%, at least 98% or at least 99% identity with SEQ ID NO. 1.

In particular, at least one mutation occurs at amino acid positions 74 and/or 142 of IL-7. Additionally or alternatively, at least one mutation occurs at amino acid positions 2 and 141, 34 and 129, and/or 47 and 92. These positions refer to SEQ ID NOs: 1, and the positions of the amino acids listed in 1.

In particular, the at least one mutation is an amino acid substitution or a set of amino acid substitutions selected from the group consisting of C2S-C141S and C47S-C92S, C2S-C141S and C34S-C129S, C S-C92S and C34S-C129S, W142H, W142F, W142Y, Q E, Y F, M17L, Q22E, K81R, D6274Q and D74N or any combination thereof. These mutations refer to the amino acid positions shown in SEQ ID No. 1. Then, for example, the mutation W142H represents replacement of tryptophan of wth-IL7 with histidine to obtain IL-7m with histidine at amino acid position 142. Such mutants are described, for example, under SEQ ID NO. 5.

In a particular aspect, the IL-7 variant comprises a substitution at amino acid position 142 of SEQ ID NO. 1 with any amino acid other than P. Such substitutions have been studied in WO2019144945A1, the disclosure of which is incorporated herein by reference. For example, W at position 142 may be replaced by G, A, V, C, L, I, M, H, Y or F. Optionally, the substitution may be selected from W142G, W142A, W142V, W142C, W142L, W142I, W142M, W142H, W Y and W142F. In a preferred aspect, the substitution is selected from W142H, W142Y and W142F, more specifically W142H.

In one aspect, IL-7m comprises multiple sets of substitutions to break disulfide bonds between C2 and C141, C47 and C92, and C34-C129. Specifically, IL-7m comprises two sets of substitutions to disrupt C2 and C141, and C47 and C92; c2 and C141, and C34-C129; or C47 and C92, and C34-C129. For example, cysteine residues may be substituted with serine to prevent disulfide bond formation. Thus, the amino acid substitutions may be selected from the group consisting of C2S-C141S and C47S-C92S (referred to as "SS 2"), C2S-C141S and C34S-C129S (referred to as "SS 1"), and C47S-C92S and C34S-C129S (referred to as "SS 3"). These mutations relate to SEQ ID NOs: 1, and a position of an amino acid shown in 1. Such IL-7m is set forth in SEQ ID NO:2 to 4 (SS 1, SS2 and SS3, respectively). Preferably, IL-7m comprises the amino acid substitutions C2S-C141S and C47S-C92S. Even more preferably, IL-7m presents the sequence shown in SEQ ID NO. 3.

In another aspect, IL-7m comprises at least one mutation selected from the group consisting of W142H, W142F and W142Y. Such IL-7m is specifically described in SEQ ID NO:5 to 7. Preferably, IL-7m comprises the mutation W142H. Even more preferably, IL-7m presents the sequence shown in SEQ ID NO. 5.

In another aspect, IL-7m comprises at least one mutation selected from the group consisting of D74E, D Q and D74N, preferably D74E and D74Q. Such IL-7m is specifically described in SEQ ID NO:12 to 14. Preferably, IL-7m comprises the mutation D74E. Even more preferably, IL-7m presents the sequence shown in SEQ ID NO. 12.

In another aspect, IL-7m comprises at least one mutation selected from Q11E, Y12F, M17L, Q E and/or K81R. These mutations relate to SEQ ID NOs: 1, and a nucleotide sequence shown in 1. Such IL-7m is set forth in SEQ ID NO: 8. the sequences shown in 9, 10, 11 and 15 are described in detail below.

In one aspect, IL-7m comprises at least one mutation consisting of: i) W142H, W F or W142Y and/or ii) D74E, D Q or D74N, preferably D74E or D74Q and/or iii) C2S-C141S and C47S-C92S, C S-C141S and C34S-C129S or C47S-C92S and C34S-C129S.

In one aspect, IL-7m comprises a W142H substitution and at least one mutation consisting of: i) D74E, D Q or D74N, preferably D74E or D74Q and/or ii) C2S-C141S and C47S-C92S, C S-C141S and C34S-C129S, or C47S-C92S and C34S-C129S.

In one aspect, IL-7m comprises a D74E substitution and at least one mutation consisting of: i) W142H, W F or W142Y and/or ii) C2S-C141S and C47S-C92S, C S-C141S and C34S-C129S or C47S-C92S and C34S-C129S.

In one aspect, IL-7m comprises mutations C2S-C141S and C47S-C92S and at least one substitution consisting of: i) W142H, W F or W142Y and/or ii) D74E, D Q or D74N, preferably D74E or D74Q.

In one aspect, IL-7m comprises i) D74E and W142H substitutions and ii) mutations C2S-C141S and C47S-C92S, C S-C141S and C34S-C129S, or C47S-C92S and C34S-C129S.

The IL-7m protein may comprise or be free of its peptide signal. Variants of IL-7 may also include altered polypeptide sequences of IL-7 (e.g., oxidized, reduced, deaminated, or truncated forms).

In one aspect, the IL-7 variants or mutants used in the present invention are recombinant IL-7. As used herein, the term "recombinant" refers to a polypeptide obtained or derived from a recombinant expression system, i.e., obtained or derived from a culture of host cells (e.g., microorganisms or insects or plants or mammals) or from a transgenic plant or animal engineered to contain a nucleic acid molecule encoding an IL-7m polypeptide. Preferably, the recombinant IL-7 is human recombinant IL-7m (e.g., human IL-7m produced in a recombinant expression system).

In one aspect, IL-7m exhibits the sequence set forth in SEQ ID NO 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 or 15. Preferably, the bifunctional molecules according to the invention comprise IL-7 variants comprising or consisting of the amino acid sequences shown in SEQ ID NOS.2-15. Even more preferably, the bifunctional molecule according to the invention comprises an IL-7 variant comprising or consisting of the amino acid sequence shown in SEQ ID NO. 2.

Even more preferably, the bifunctional molecule according to the invention comprises an IL-7 variant comprising or consisting of the amino acid sequence shown in SEQ ID NO 3, 5 or 12.

In one aspect, the invention provides bifunctional molecules comprising variants of IL-7 that have reduced immunogenicity as compared to wild-type IL-7 proteins, particularly by removing T cell epitopes within IL-7 that can stimulate an immune response. Examples of such IL-7 are described in WO 2006061219.

The invention also relates to any fusion protein comprising an IL-7 variant or mutant disclosed herein. IL-7 variants or mutants may be fused via their N-terminus or C-terminus.

The invention provides, inter alia, bifunctional molecules comprising IL-7m, an anti-PD-1 binding domain and an Fc fragment, and optionally a peptide linker.

In particular, the Fc domain is covalently conjugated (e.g., by gene fusion or chemical coupling) to IL-7, preferably by a peptide linker as disclosed below.

In particular, conjugation of IL-7m to an Fc domain is covalent, direct or not (i.e., via a linker) and/or chemical, enzymatic or genetic. Conjugation may be by any acceptable means of bonding known in the art. In this regard, coupling may be via one or more covalent, ionic, hydrogen, hydrophobic or van der Waals bonds that may or may not be cleavable in physiological media or within a cell.

In particular, chemical conjugation may be performed by exposing sulfhydryl groups (Cys), attaching affinity tags (e.g., 6 histidine, flag tags, strep tags, spyCatcher, etc.) to the Fc domain or IL7-m, or incorporating unnatural amino acids or compounds for click chemistry conjugation.

In a preferred embodiment, conjugation is obtained by gene fusion (i.e., by expressing the nucleic acid construct encoding the Fc domain and IL-7 as a gene fusion in a suitable system). In one aspect, the invention features a fusion protein that includes a first portion that includes an immunoglobulin (Ig) chain, particularly an Fc domain, and a second portion that includes interleukin-7 (IL-7).

The acquisition of IL-7 mutants is described in particular in WO 2020/12377, which is incorporated herein by reference.

PD-1 targeting antigen binding domains on immune cells

According to the invention, the antigen binding domain specifically binds to PD-1, in particular PD-1 expressed on the surface of immune cells. In particular, the antigen binding domain is not directed against a target expressed on a tumor cell.

As used herein, the expression "antigen binding domain" relates to any moiety, such as peptides, polypeptides, proteins, fusion proteins and antibodies, having the ability to bind PD-1. In particular, the term includes antibodies or antigen binding fragments thereof, and antibody mimetics or mimics.

In one embodiment, the "antigen binding domain" is selected from an antibody or fragment thereof, and an antibody mimetic or mimetic. Those skilled in the biochemical arts are familiar with antibody mimics or mimics, such as Gebauer and Skerra,2009,Curr Opin Chem Biol 13 (3): 245-255. Examples of antibody mimics include: affibodies (also known as trinnectins; nygren,2008,FEBS J,275,2668-2676); CTLD (also known as tetranectin; innovation Pharmac. Technology (2006), 27-30); adnectins (also known as monomers; meth.mol.biol. (352) (2007), 95-109); anticalins (Drug Discovery Today (2005), 10, 23-33); DARPins (ankyrin; nat. Biotechnol. (2004), 22, 575-582); avimers (Nat. Biotechnol. (2005), 23, 1556-1561); microsomes (FEBS J, (2007), 274,86-95); aptamers (expert. Opin. Biol. Ther. (2005), 5, 783-797); kunitz domain (j.pharmacol.exp.ter. (2006) 318, 803-809); affilins (trends. Biotechnol. (2005), 23, 514-522); affitins (Krehhenbrink et al, 2008, J.mol. Biol.383 (5): 1058-68), alfabodies (Desmet, J.; et al, 2014,Nature Communications.5:5237), fynomer (Grablovski D; et al, 2007,J Biol Chem.282 (5): 3196-320) 4) and affimers (Avacta Life Sciences, wetherby, UK).

Preferably, the antigen binding domain is an antibody fragment. Even more preferably, the antigen binding domain is a human, humanized or chimeric antigen binding fragment.

With respect to the "binding" ability of an antigen binding domain, the term "binding" refers to antibodies, including antibody fragments and derivatives, that recognize and contact another peptide, polypeptide, protein or molecule, particularly PD-1. The terms "specifically bind," "specifically bind to," "selectively bind to," and "selectively bind to" a particular target refer to an antigen binding domain that recognizes and binds to the particular target, but does not substantially recognize or bind to other molecules in the sample. For example, an antibody or antigen binding domain that specifically (or preferentially) binds an antigen is an antibody or antigen binding domain that binds an antigen with greater affinity, avidity, ease, and/or longer duration than it binds other molecules, for example. Preferably, the term "specific binding" means that the binding between the antibody or antigen binding domain and the antigen is at or below 10 ^-7 Binding affinity contact of M. In certain aspects, the antibody or antigen binding domain is at or below 10 ^-8 M、10 ^-9 M or 10 ^-10 Affinity binding of M.

Optionally, the antigen binding domain may be a Fab domain, fab', single chain variable fragment (scFV), or single domain antibody (sdAb). The antigen binding domain preferably comprises a heavy chain variable region (VH) and a light chain variable region (VL).

When the antigen binding domain is a Fab or Fab', the bifunctional molecule comprises one heavy chain and one light chain constant domain (i.e. CH and CL), the heavy chain being linked at its C-terminal end to IL-7m.

In one aspect, PD-1 is specifically expressed by immune cells in healthy subjects or subjects suffering from a disease, particularly such as cancer. This means that the expression level of PD-1 in immune cells is higher than that of other cells, or that the proportion of immune cells expressing PD-1 to the total number of immune cells is higher than that of other cells expressing PD-1 to the total number of other cells. Preferably, the expression level or ratio is 2, 5, 10, 20, 50 or 100 times higher. More specifically, the expression level or ratio may be determined for a specific type of immune cell (e.g., T cell, more specifically cd8+ T cell, effector T cell, or depleted T cell) or in a specific case (e.g., a subject suffering from a disease such as cancer or infection).

As used herein, "immune cells" refers to cells involved in innate and adaptive immunity, such as leukocytes (leukocytes), lymphocytes (T cells, B cells, natural Killer (NK) cells, and natural killer T cells (NKT)), and bone marrow-derived cells (neutrophils, eosinophils, basophils, monocytes, macrophages, dendritic cells) derived from Hematopoietic Stem Cells (HSCs) produced in the bone marrow. In particular, the immune cells may be selected from a non-exhaustive list comprising B cells, T cells, in particular cd4+ T cells and cd8+ T cells, NK cells, NKT cells, APC cells, macrophages, dendritic cells and monocytes.

Preferably, the antigen binding domain specifically binds to PD-1 expressed by an immune cell selected from the group consisting of B cells, T cells, natural killer cells, dendritic cells, monocytes and Innate Lymphocytes (ILC).

Even more preferably, the immune cells are T cells. "T cells" or "T lymphocytes" as used herein include, for example, CD4+ T cells, CD8+ T cells, T helper type 1T cells, T helper type 2T cells, regulatory T, T helper type 17T cells, and suppressor T cells. In a very specific aspect, the immune cells are depleted T cells.

In a specific aspect, the immune cells are effector memory stem cell-like T cells.

In a specific aspect, the immune cells are depleted T cells or effector memory stem cell-like T cells, and the PD-1 is expressed on the surface of the depleted T cells or effector memory stem cell-like T cells. T cell depletion is a state of gradual loss of T cell function, proliferation capacity and cytotoxic potential, ultimately leading to its loss. T cell depletion can be triggered by a variety of factors, such as sustained contact with antigen or inhibitory receptors (including PD-1).

In a preferred aspect, the antigen binding domain has antagonistic activity against PD-1.

A number of antibodies to PD-1 have been described in the art. The person skilled in the art knows how to generate individual antigen binding domains based on the sequences of known antibodies.

Several anti-PD-1 drugs have been clinically approved and others are still in the clinical development stage. For example, the anti-PDl antibody may be selected from the group consisting of palbociclizumab (also known as Keytruda lambrolizumab, MK-3475), nivolumab (Opdivo, MDX-1106, BMS-936558, ONO-4538), pidiclizumab (CT-011), cimipn Li Shan anti (Libtayo), karellizumab, AUNP12, AMP-224, AGEN-2034, BGB-a317 (tirelizumab), PDR001 (spatazumab), MK-3477, SCH-900475, PF-06801591, JNJ-63723283, ji Nuoli mumab (CBT-501), LZM-009, BCD-100, SHR-1201, BAT-1306, AK-103 (HX-008), MEDI-0680 (also known as AMP-514) MEDI0608, JS001 (see Si-Yang Liu et al, j. Hemalol. 10); 136 (2017)), BI-754091, CBT-501, INCSHR1210 (also known as SHR-1210), TSR-042 (also known as ANB 011), GLS-010 (also known as WBP 3055), AM-0001 (Armo), STI-1110 (see WO 2014/194302), AGEN2034 (see WO 2017/040790), MGA012 (see WO 2017/19846) or IBI308 (see 2017/024465, WO2017/025016, WO2017/132825 and WO 2017/133540), monoclonal antibodies 5C4, 17D8, 2D3, 4H1, 4A11, 7D3 and 5F4, described in WO 2006/121168. Bifunctional or bispecific molecules targeting PD-1 are also known, such as RG7769 (Roche), xmAb20717 (Xencor), MEDI5752 (AstraZeneca), FS118 (F-star), SL-279252 (Takeda) and XmAb23104 (Xencor). Specifically, the antigen binding domain targeting PD-1 comprises the 6 CDRs or VH and VL of the anti-PD 1 antibodies selected in this list. Such antigen binding domains may be in particular Fab or svFc domains derived from the antibodies. In a preferred aspect, the antigen binding domain targeting PD-1 comprises 6 CDRs or VH and VL of an anti-PD 1 antibody selected from palbociclizumab (also known as Keytrudalambrolizumab, MK-3475) or nivolumab (Opdivo, MDX-1106, BMS-936558, ONO-4538) and may be, for example, a Fab or scFc domain.

In a particular aspect, the anti-PD 1 antibody from which the antigen binding domain is derived may be palbociclizumab (also known as Keytruda lambrolizumab, MK-3475) or nivolumab (Opdivo, MDX-1106, BMS-936558, ONO-4538).

Specifically, the target is PD-1 and the antigen binding domain of the bifunctional molecule is an antibody, fragment or derivative thereof or an antibody mimetic specific for PD-1. Then, in a specific aspect, the antigen binding domain comprised in the bifunctional molecule according to the invention is derived from an anti-PD 1 antibody or an antigen binding fragment thereof, preferably a human, humanized or chimeric anti-PD 1 antibody or an antigen binding fragment thereof. Preferably, the antigen binding domain is an antagonist of PD-1. Thus, bifunctional molecules bind to the blocking of the IL-7 receptor effect and PD-1 inhibition effect of IL-7 variants or mutants and may have a synergistic effect on the activation of T cells, in particular depleted T cells, and more particularly on TCR signaling. Preferably, the antigen binding domain is an antagonist of PD-1.

In a very specific aspect of the present disclosure, the antigen binding domain targets PD-1 and is derived from an antibody disclosed in WO2020/127366, the disclosure of which is incorporated herein by reference.

Then, the antigen binding domain comprises:

(i) Heavy chain variable domains comprising HCDR1, HCDR2 and HCDR3, and

(ii) Light chain variable domains comprising LCDR1, LCDR2 and LCDR3,

wherein:

-the heavy chain CDRl (HCDR 1) comprises or consists of the amino acid sequence of SEQ ID NO:51, optionally having one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof at any position other than position 3 of SEQ ID NO: 51;

-heavy chain CDR2 (HCDR 2) comprises or consists of the amino acid sequence of SEQ ID NO:53, optionally having one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof at any position other than positions 13, 14 and 16 of SEQ ID NO: 53;

-heavy chain CDR3 (HCDR 3) comprises or consists of the amino acid sequence of SEQ ID NO:54, wherein Xl is D or E and X2 is selected from T, H, A, Y, N, E and S, preferably from H, A, Y, N, E; optionally having one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof at any position other than positions 2, 3, 7 and 8 of SEQ ID NO. 54;

-the light chain CDRl (LCDRl) comprises or consists of the amino acid sequence of SEQ ID NO:63, wherein X is G or T, optionally with one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof at any position other than positions 5, 6, 10, 11 and 16 of SEQ ID NO: 63;

-light chain CDR2 (LCDR 2) comprises or consists of the amino acid sequence of SEQ ID NO:66, optionally with one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof; and

light chain CDR3 (LCDR 3) comprises or consists of the amino acid sequence of SEQ ID NO. 16, optionally with one, two or three modifications selected from substitutions, additions, deletions and any combination thereof at any position other than positions 1, 4 and 6 of SEQ ID NO. 16.

In one aspect, the antigen binding domain comprises:

(i) Heavy chain variable domains comprising HCDR1, HCDR2 and HCDR3, and

(ii) Light chain variable domains comprising LCDR1, LCDR2 and LCDR3,

wherein:

-heavy chain CDR3 (HCDR 3) comprises or consists of the amino acid sequence of SEQ ID NO:54, wherein Xl is D and X2 is selected from T, H, A, Y, N, E and S, preferably from H, A, Y, N, E; or X1 is E and X2 is selected from T, H, A, Y, N, E and S, preferably from H, A, Y, N, E and S; optionally having one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof at any position other than positions 2, 3, 7 and 8 of SEQ ID NO. 54;

In another embodiment, the antigen binding domain comprises or consists essentially of: (i) A heavy chain comprising the CDRL of SEQ ID NO. 51, the CDR2 of SEQ ID NO. 53 and the CDR3 of SEQ ID NO. 55, 56, 57, 58, 59, 60, 61 or 62; (ii) A light chain comprising CDR1 of SEQ ID NO. 64, 65 or 89, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16 or 90.

In another embodiment, the antigen binding domain comprises or consists essentially of: (i) A heavy chain comprising the CDRL of SEQ ID NO. 51, the CDR2 of SEQ ID NO. 53 and the CDR3 of SEQ ID NO. 55, 56, 57, 58, 59, 60, 61 or 62; (ii) A light chain comprising CDR1 of SEQ ID NO. 64 or 65, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16.

In another aspect, the antigen binding domain comprises or consists essentially of:

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 55; (ii) A light chain comprising CDR1 of SEQ ID NO. 64, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO:51, CDR2 of SEQ ID NO:53 and CDR3 of SEQ ID NO: 56; (ii) A light chain comprising CDR1 of SEQ ID NO:64, CDR2 of SEQ ID NO:66 and CDR3 of SEQ ID NO:16, or

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 57; (ii) A light chain comprising CDR1 of SEQ ID NO. 64, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 58; (ii) A light chain comprising CDR1 of SEQ ID NO. 64, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 59; (ii) A light chain comprising CDR1 of SEQ ID NO. 64, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 60; (ii) A light chain comprising CDR1 of SEQ ID NO. 64, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 61; (ii) A light chain comprising CDR1 of SEQ ID NO. 64, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 62; (ii) A light chain comprising CDR1 of SEQ ID NO:64, CDR2 of SEQ ID NO:66 and CDR3 of SEQ ID NO:16, or

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 55; (ii) A light chain comprising CDR1 of SEQ ID NO. 65, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO:51, CDR2 of SEQ ID NO:53 and CDR3 of SEQ ID NO: 56; (ii) A light chain comprising CDR1 of SEQ ID NO. 65, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 57; (ii) A light chain comprising CDR1 of SEQ ID NO. 65, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 58; (ii) A light chain comprising CDR1 of SEQ ID NO. 65, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 59; (ii) A light chain comprising CDR1 of SEQ ID NO. 65, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 60; (ii) A light chain comprising CDR1 of SEQ ID NO. 65, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 61; (ii) A light chain comprising CDR1 of SEQ ID NO. 65, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 62; (ii) A light chain comprising CDR1 of SEQ ID NO. 65, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16.

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 55; (ii) A light chain comprising CDR1 of SEQ ID NO. 89, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 90; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO:51, CDR2 of SEQ ID NO:53 and CDR3 of SEQ ID NO: 56; (ii) A light chain comprising CDR1 of SEQ ID NO. 89, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 90; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 57; (ii) A light chain comprising CDR1 of SEQ ID NO. 89, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 90; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 58; (ii) A light chain comprising CDR1 of SEQ ID NO. 89, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 90; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 59; (ii) A light chain comprising CDR1 of SEQ ID NO. 89, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 90; or alternatively

(i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 60; (ii) A light chain comprising CDR1 of SEQ ID NO:89, CDR2 of SEQ ID NO:66 and CDR3 of SEQ ID NO: 90.

In one aspect, the anti-PD 1 antigen-binding fragments according to the invention comprise framework regions, in particular heavy chain variable region framework regions (HFR) HFR1, HFR2, HFR3 and HFR4 and light chain variable region framework regions (LFR) LFR1, LFR2, LFR3 and LFR4.

Preferably, an anti-PD 1 antigen-binding fragment according to the invention comprises a human or humanized framework region. A "human acceptor framework" for purposes herein is a framework comprising an amino acid sequence derived from a light chain variable domain (VL) framework or a heavy chain variable domain (VH) framework of a human immunoglobulin framework or a human consensus framework, as defined below. The human acceptor framework derived from the human immunoglobulin framework or the human consensus framework may comprise the same amino acid sequence thereof, or it may comprise an amino acid sequence change. In some embodiments, the number of amino acid changes is 10 or less, 9 or less, 8 or less, 7 or less, 6 or less, 5 or less, 4 or less, 3 or less, or 2 or less. In some embodiments, the VL acceptor human framework is identical in sequence to the VL human immunoglobulin framework sequence or the human consensus framework sequence. A "human consensus framework" is a framework representing the amino acid residues most commonly found in a selected human immunoglobulin VL or VH framework sequence.

In particular, the anti-PD 1 antigen-binding fragment comprises heavy chain variable region framework regions (HFR) HFR1, HFR2, HFR3 and HFR4 comprising the amino acid sequences of SEQ ID NOS: 41, 42, 43 and 44, respectively, optionally with one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof at any position of HFR3 other than positions 27, 29 and 32, i.e., preferably, the anti-PD 1 antigen-binding fragment comprises HFR1 of SEQ ID NO:41, HFR2 of SEQ ID NO:42, HFR3 of SEQ ID NO:43 and HFR4 of SEQ ID NO: 44.

In specific embodiments, the anti-PD 1 antigen-binding fragment comprises a light chain variable region framework region (LFR) LFR1, LFR2, LFR3 and LFR4 comprising the amino acid sequences of SEQ ID NOs: i) 45, 46, 47 and 48, ii) 91, 92, 93 and 94 or iii) 95, 96, 97 and 98, respectively, optionally with one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof. Preferably, the humanized anti-PD 1 antigen-binding fragment comprises LFR1 of SEQ ID NO:45, 91 or 95, LFR2 of SEQ ID NO:46, 92 or 96, LFR3 of SEQ ID NO:47, 93 or 97 and LFR4 of SEQ ID NO:48, 94 or 98.

Alternatively or additionally, the anti-PD 1 antigen-binding fragment comprises light chain variable region framework regions (LFR) LFR1, LFR2, LFR3, and LFR4 comprising the amino acid sequences of SEQ ID NOs 45, 46, 47, and 48, respectively, optionally with one, two, or three modifications selected from the group consisting of substitutions, additions, deletions, and any combination thereof. Preferably, the humanized anti-PD 1 antigen-binding fragment comprises LFR1 of SEQ ID NO. 45, LFR2 of SEQ ID NO. 46, LFR3 of SEQ ID NO. 47 and LFR4 of SEQ ID NO. 48.

Alternatively or additionally, the anti-PD 1 antigen-binding fragment comprises light chain variable region framework regions (LFR) LFR1, LFR2, LFR3, and LFR4 comprising the amino acid sequences of SEQ ID NOs 91, 92, 93, and 94, respectively, optionally with one, two, or three modifications selected from the group consisting of substitutions, additions, deletions, and any combination thereof. Preferably, the humanized anti-PD 1 antigen-binding fragment comprises LFR1 of SEQ ID NO. 91, LFR2 of SEQ ID NO. 92, LFR3 of SEQ ID NO. 93 and LFR4 of SEQ ID NO. 94. Preferably, such a framework is associated with CDR1 of SEQ ID NO:89, CDR2 of SEQ ID NO:66, CDR3 of SEQ ID NO:90, optionally with one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof, respectively.

Alternatively or additionally, the anti-PD 1 antigen-binding fragment comprises light chain variable region framework regions (LFR) LFR1, LFR2, LFR3, and LFR4 comprising the amino acid sequences of SEQ ID NOs 95, 96, 97, and 98, respectively, optionally with one, two, or three modifications selected from the group consisting of substitutions, additions, deletions, and any combination thereof. Preferably, the humanized antigen binding fragment comprises LFR1 of SEQ ID NO. 95, LFR2 of SEQ ID NO. 96, LFR3 of SEQ ID NO. 97 and LFR4 of SEQ ID NO. 98, optionally with one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof, respectively.

The VL and VH domains of the antigen binding domains comprised in the bifunctional molecules according to the invention may comprise four framework regions interrupted by three complementarity determining regions, preferably operably linked in the following order: FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4 (from amino terminus to carboxy terminus).

In one aspect, the antigen binding domain comprises or consists essentially of:

(a) A heavy chain variable region (VH) comprising or consisting of the amino acid sequence of SEQ ID No. 17, wherein X1 is D or E and X2 is selected from T, H, A, Y, N, E and S, preferably from H, A, Y, N, E; optionally in addition to SEQ ID NO:17, having one, two or three modifications selected from the group consisting of substitutions, additions, deletions, and any combination thereof at any position other than positions 7, 16, 17, 20, 33, 38, 43, 46, 62, 63, 65, 69, 73, 76, 78, 80, 84, 85, 88, 93, 95, 96, 97, 98, 100, 101, 105, 106, and 112;

(b) A light chain variable region (VL) comprising or consisting of the amino acid sequence of SEQ ID NO:26, wherein X is G or T, optionally having one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof at any position except positions 3, 4, 7, 14, 17, 18, 28, 29, 33, 34, 39, 42, 44, 50, 81, 88, 94, 97, 99 and 105 of SEQ ID NO: 26.

(a) A heavy chain variable region (VH) comprising or consisting of the amino acid sequence of SEQ ID NO:18, 19, 20, 21, 22, 23, 24 or 25, optionally having one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof at any position other than positions 7, 16, 17, 20, 33, 38, 43, 46, 62, 63, 65, 69, 73, 76, 78, 80, 84, 85, 88, 93, 95, 96, 97, 98, 100, 101, 105, 106 and 112 of SEQ ID NO:18, 19, 20, 21, 22, 23, 24 or 25;

(b) A light chain variable region (VL) comprising or consisting of the amino acid sequence of SEQ ID No. 27 or SEQ ID No. 28, optionally having one, two or three modifications at positions 3, 4, 7, 14, 17, 18, 28, 29, 33, 34, 39, 42, 44, 50, 81, 88, 94, 97, 99 and 105 of SEQ ID No. 27 or SEQ ID No. 28 selected from the group consisting of substitutions, additions, deletions and any combination thereof.

(a) A heavy chain variable region (VH) comprising or consisting of the amino acid sequence of SEQ ID NO:18, 19, 20, 21, 22, 23, 24 or 25;

(b) A light chain variable region (VL) comprising or consisting of the amino acid sequence of SEQ ID No. 27 or SEQ ID No. 28.

In one aspect, the bifunctional molecule comprises a framework region, in particular heavy chain variable region framework regions (HFR) HFR1, HFR2, HFR3 and HFR4, and light chain variable region framework regions (LFR) LFR1, LFR2, LFR3 and LFR4, in particular HFR1, HFR2, HFR3 and HFR4 comprising the amino acid sequences of SEQ ID NOs: 41, 42, 43 and 44, respectively, optionally having one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof at any position other than positions 27, 29 and 32 of HFR3 (i.e. SEQ ID NO: 43). Preferably, the bifunctional molecule comprises HFR1 of SEQ ID NO. 41, HFR2 of SEQ ID NO. 42, HFR3 of SEQ ID NO. 43 and HFR4 of SEQ ID NO. 44. Furthermore, the bifunctional molecule may comprise a light chain variable region framework region (LFR) LFR1, LFR2, LFR3 and LFR4 comprising the amino acid sequences of SEQ ID NOs 45, 46, 47 and 48, respectively, optionally with one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof. Preferably, the bifunctional molecule comprises LFR1 of SEQ ID NO. 45, LFR2 of SEQ ID NO. 46, LFR3 of SEQ ID NO. 47 and LFR4 of SEQ ID NO. 48. Alternatively, the bifunctional molecule may comprise light chain variable region framework regions (LFR) LFR1, LFR2, LFR3 and LFR4 comprising the amino acid sequences of SEQ ID NOs 91, 92, 93 and 94, respectively, optionally with one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof. Preferably, the bifunctional molecule comprises LFR1 of SEQ ID NO. 91, LFR2 of SEQ ID NO. 92, LFR3 of SEQ ID NO. 93 and LFR4 of SEQ ID NO. 94. Alternatively, the bifunctional molecule may comprise light chain variable region framework regions (LFR) LFR1, LFR2, LFR3 and LFR4 comprising the amino acid sequences of SEQ ID NOs 95, 96, 97 and 98, respectively, optionally with one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof. Preferably, the bifunctional molecule comprises LFR1 of SEQ ID NO. 95, LFR2 of SEQ ID NO. 96, LFR3 of SEQ ID NO. 97 and LFR4 of SEQ ID NO. 98.

In another aspect, the antigen binding domain comprises or consists essentially of any combination of VH and VL described in tables D and E.

In another aspect, the antigen binding domain comprises or consists essentially of any combination of the heavy chain variable region (VH) and the light chain variable region (VL):

table D.VH-VL combinations

In a very specific aspect, the antigen binding domain comprises or consists essentially of the heavy chain variable region (VH) of SEQ ID NO. 24 and the light chain variable region (VL) of SEQ ID NO. 28.

table E.VH-VL combinations

Peptide linker

In a specific aspect, the bifunctional molecule according to the invention further comprises a peptide linker linking the antigen binding domain and IL-7m to the Fc chain. Peptide linkers are typically of sufficient length and flexibility to ensure that the antigen binding domain of the IL-7m and the linker linkage therebetween has sufficient spatial freedom to function.

In one aspect of the disclosure, IL-7m is preferably linked to the Fc chain by a peptide linker. In one aspect of the disclosure, the antigen binding domain may be linked to the Fc chain by a naturally occurring hinge in the heavy chain (a CH2 domain for linking the VH domain, particularly the CH1 domain, to the Fc chain).

As used herein, the term "linker" refers to a sequence of at least one amino acid. Such linkers may be used to prevent steric hindrance. The length of the linker is typically 3-44 amino acid residues. Preferably, the linker has 3-30 amino acid residues. In some aspects, the linker has 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 amino acid residues.

The linker sequence may be a naturally occurring sequence or a non-naturally occurring sequence. If used for therapeutic purposes, the linker is preferably non-immunogenic in a subject for which the bifunctional molecule is useful. One useful set of linker sequences are those derived from the hinge region of a heavy chain antibody, as described in WO 96/34103 and WO 94/04678. Other examples are polyalanine linker sequences. Further preferred examples of linker sequences are Gly/Ser linkers of different lengths, including (Gly 4 Ser) 4, (Gly 4 Ser) 3, (Gly 4 Ser) 2, gly4Ser, gly3, gly2Ser and (Gly 3Ser 2) 3, in particular (Gly 4 Ser) 3. Preferably, the linker is selected from (Gly 4 Ser) 4, (Gly 4 Ser) 3 and (Gly 3Ser 2) 3. Even more preferably, the linker is (GGGGS) 3.

In one aspect, the linker comprised in the bifunctional molecule is selected from (Gly 4 Ser) 4, (Gly 4 Ser) 3, (Gly 4 Ser) 2, gly4Ser, gly3, gly2Ser and (Gly 3Ser 2) 3, preferably (Gly 4 Ser) 3. Preferably, the linker is selected from (Gly 4 Ser) 4, (Gly 4 Ser) 3 and (Gly 3Ser 2) 3.

Fc domain

The Fc domain of the bifunctional molecule may be part of an antigen binding domain, in particular the heavy chain of an IgG immunoglobulin. In fact, when the antigen binding domain is a Fab, the bifunctional molecule may comprise a heavy chain comprising Variable Heavy (VH), CH1, hinge, CH2 and CH3 domains. However, the bifunctional molecule may also have other structures, such as scFv or diabodies. For example, it may comprise an Fc domain linked to an antigen binding domain.

The Fc domain may be derived from a heavy chain constant domain of a human immunoglobulin heavy chain, such as IgGl, igG2, igG3, igG4, or other classes. Preferably, the bifunctional molecule comprises an IgG1 or IgG4 heavy chain constant domain.

Preferably, the Fc domain comprises CH2 and CH3 domains. Optionally, it may comprise all or part of the hinge region, CH2 domain and/or CH3 domain. In some aspects, the CH2 and/or CH3 domains are derived from a human IgG4 or IgG1 heavy chain. Preferably, the Fc domain comprises all or part of the hinge region. The hinge region may be derived from an immunoglobulin heavy chain, such as IgGl, igG2, igG3, igG4, or other class. Preferably, the hinge region is derived from human IgGl, igG2, igG3, igG4. More preferably, the hinge region is derived from a human or humanized IgG1 or IgG4 heavy chain.

The IgG1 hinge region has three cysteines, two of which are involved in disulfide bonds between the two heavy chains of the immunoglobulin. These same cysteines allow efficient and consistent disulfide bond formation between Fc portions. Thus, preferred hinge regions of the invention are derived from IgG1, more preferably from human IgG1. In some aspects, the first cysteine within the human IgG1 hinge region is mutated to another amino acid, preferably serine.

The hinge region of IgG4 is known to be ineffective in forming interchain disulfide bonds. However, suitable hinge regions for use in the present invention may be derived from an IgG4 hinge region, preferably containing mutations that enhance the correct formation of disulfide bonds between heavy chain derived moieties (Angal S, et al (1993) mol. Immunol., 30:105-8). More preferably, the hinge region is derived from a human IgG4 heavy chain.

The bifunctional molecule comprises a dimeric Fc domain. Thus, the two monomers each comprise an Fc chain capable of forming a dimeric Fc domain. The dimeric Fc domain may be homodimeric, with each Fc monomer being identical or substantially identical. Alternatively, the dimeric Fc domain may be heterodimeric, with each Fc monomer being different and complementary to promote formation of the heterodimeric Fc domain.

More specifically, the Fc domain is a heterodimeric Fc domain. Heterodimeric Fc domains are formed by altering the amino acid sequence of each monomer. Heterodimeric Fc domains rely on amino acid variants in different constant regions on each chain to promote heterodimer formation and/or allow easier purification of heterodimers relative to homodimers. There are many mechanisms available for producing the heterodimers of the present invention. Furthermore, as will be appreciated by those skilled in the art, these mechanisms may be combined to ensure a high degree of heterodimerization. Thus, amino acid variants that result in heterodimer production are referred to as "heterodimeric variants". Heterodimerization variants may include steric variants (e.g., the "knob and hole" or "inclined" variants described below and the "charge pair" variants described below) as well as "pi variants" that allow for purification of homodimers from heterodimers. WO2014/145806, the entire contents of which are incorporated herein by reference, discloses useful mechanisms for heterodimerization, including "pestle and mortar", "electrostatic steering" or "charge pair", pi variants and generally additional Fc variants. See also Ridgway et al Protein Engineering (7): 617 (1996); atwell et al, J.mol. Biol. 1997:270; U.S. Pat. No.8,216,805, merchant et al, nature Biotech.16:677 (1998), the entire contents of which are incorporated herein by reference. For "electrostatic manipulation," please see Gunasekaran et al, j. Biol. Chem.285 (25): 19637 (2010), the entire contents of which are incorporated herein by reference. For pi variants, see US2012/0149876, the entire contents of which are incorporated herein by reference.

Then, in a preferred aspect, the heterodimeric Fc domain comprises a first Fc chain and a complementary second Fc chain based on a "pestle and mortar" technique. For example, a first Fc strand is a "pestle" or K strand, meaning that it contains substitutions that characterize a pestle strand, and a second Fc strand is a "mortar" or H strand, meaning that it contains substitutions that characterize a mortar strand. Vice versa, the first Fc strand is a "mortar" or H strand, meaning that it contains substitutions that characterize mortar strands, and the second Fc strand is a "pestle" or K strand, meaning that it contains substitutions that characterize pestle strands. In a preferred aspect, the first Fc chain is a "mortar" or H chain and the second Fc chain is a "pestle" or K chain.

Optionally, the heterodimeric Fc domain may comprise one heterodimeric Fc chain comprising the substitutions shown in table F below and another heterodimeric Fc chain comprising the substitutions shown in table F below.

Table F (numbering according to EU index)

In a preferred aspect, the first Fc strand is a "mortar" or H strand and comprises the substitutions T366S/L368A/Y407V/Y349C and the second Fc strand is a "pestle" or K strand and comprises the substitutions T366W/S354C.

Optionally, the Fc chain may also comprise additional substitutions.

In particular, for bifunctional molecules that target cell surface molecules (particularly molecules on immune cells), it may be desirable to abrogate effector functions. It may also be desirable to engineer the Fc region to reduce or increase effector function of the bifunctional molecule.

In certain aspects, amino acid modifications can be introduced into the Fc region to produce Fc region variants. In certain aspects, the Fc region variant possesses some, but not all, effector functions. Such bifunctional molecules may be useful, for example, in applications where the in vivo half-life of the antibody is important but some effector functions are unnecessary or detrimental. Many substitutions or deletions with altered effector functions are known in the art.

In one aspect, the constant region of the Fc domain contains a mutation that reduces affinity for Fc receptors or reduces Fc effector function. For example, the constant region may contain mutations that eliminate glycosylation sites within the IgG heavy chain constant region. Preferably, the CH2 domain contains a mutation that eliminates the glycosylation site within the CH2 domain.

In a particular aspect, the Fc domain is modified to increase binding to FcRn, thereby increasing the half-life of the bifunctional molecule. In another or additional aspect, the Fc domain is modified to reduce binding to fcγr, thereby reducing ADCC or CDC, or to increase binding to fcγr, thereby increasing ADCC or CDC.

Amino acid changes near the junction of the Fc portion and the non-Fc portion can significantly increase the serum half-life of the Fc fusion protein, as shown in WO 01/58957. Thus, the junction region of a protein or polypeptide of the invention may contain alterations that are preferably located within about 10 amino acids of the junction point relative to the naturally occurring sequences of immunoglobulin heavy chains and erythropoietin. These amino acid changes can result in increased hydrophobicity. In one embodiment, the constant region is derived from an IgG sequence in which the C-terminal lysine residue is replaced. Preferably, the C-terminal lysine of the IgG sequence is replaced with a non-lysine amino acid, such as alanine or leucine, to further increase serum half-life.

In one embodiment, the constant region of the Fc domain has one or any combination of the mutations described in table G below.

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Table G: suitable human engineered antibody Fc domains. The Numbering of the residues in the heavy chain constant region is according to EU Numbering (Edelman, G.M.et al., proc. Natl. Acad. USA,63,78-85 (1969); www.imgt.org/IMGT scientific Chart/number/Hu_IGHGnber. Html#refs)

In a specific aspect, the bifunctional molecule comprises a human IgGl heavy chain constant domain or an IgG1 Fc domain, optionally with a substitution or combination of substitutions selected from the group consisting of: T250Q/M428L; M252Y/S254T/T256 E+H2433K/N434F; E233P/L234V/L235A/G236A+A327G/A330S/P331S; E333A; S239D/A330L/I332E; P257I/Q311; K326W/E333S; S239D/I332E/G236A; N297A; L234A/L235A; P329G; n297A+M252Y/S254T/T256E; K322A and K444A, preferably selected from N297A optionally in combination with M252Y/S254T/T256E, and L234A/L235A optionally with P329G.

In a specific aspect, the bifunctional molecule comprises a human IgGl heavy chain constant domain or an IgG1 Fc domain, optionally with a substitution or combination of substitutions selected from the group consisting of: T250Q/M428L; M252Y/S254T/T256 E+H2433K/N434F; E233P/L234V/L235A/G236A+A327G/A330S/P331S; E333A; S239D/A330L/I332E; P257I/Q311; K326W/E333S; S239D/I332E/G236A; N297A; L234A/L235A; P329G; n297A+M252Y/S254T/T256E; K322A, K444A, K444E, K444D, K444G, K S, M428L, L309D, Q H, N35434S, M L+N434S and L309D+Q311H+N434S, preferably selected from N297A optionally in combination with M252Y/S254T/T256E, and L234A/L235A optionally in combination with P329G.

Bifunctional molecules comprising a human IgGl heavy chain constant domain or IgG1 Fc domain with a replacement L234A/L235A/P329G combination greatly reduce or completely inhibit ADCC, ADCP and/or CDC caused by said bifunctional molecules, thereby reducing non-specific cytotoxicity.

In another aspect, the bifunctional molecule comprises a human IgG4 heavy chain constant domain or a human IgG4 Fc domain, optionally with a substitution or combination of substitutions selected from the group consisting of: S228P; L234A/L235A; P329G, S P+M252Y/S254T/T256E and K444A. Even more preferably, the bifunctional molecule, preferably according to the invention, comprises an IgG4 Fc region with S228P of stabilized IgG 4.

In another aspect, the bifunctional molecule comprises a human IgG4 heavy chain constant domain or a human IgG4 Fc domain, optionally with a substitution or combination of substitutions selected from the group consisting of: S228P; L234A/L235A; L234A/L235A/P329G, P G, S P+M252Y/S254T/T256E, K444A K444E, K444D, K444G and K444S. Even more preferably, the bifunctional molecule, preferably according to the invention, comprises an IgG4 Fc region with S228P of stabilized IgG 4.

As referred to herein "/" and "+" refer to accumulated mutations. Thus, the mutation S228P+M252Y/S254T/T256E refers to the following mutations: S228P, M252Y, S T and T256E.

The bifunctional molecules comprising a human IgG4 heavy chain constant domain or IgG4 Fc domain with substitution P329G reduce ADCC and/or CDC caused by the bifunctional molecules, thereby reducing non-specific cytotoxicity.

All subclasses of human IgG carry the C-terminal lysine residue of the antibody heavy chain (K444), which is readily cleaved in the circulation. This cleavage in the blood can impair or reduce the biological activity of the bifunctional molecule by releasing the IL-7m linked to the bifunctional molecule.

To address this problem, the K444 amino acid in the IgG domain may be replaced with another amino acid to reduce proteolytic cleavage (a mutation commonly used by antibodies). Then, in one aspect, the bifunctional molecule comprises at least one further amino acid substitution consisting of K444A, K444E, K444D, K G or K444S, preferably K444A.

In particular, the K444 amino acid in the IgG domain can be replaced with alanine to reduce proteolytic cleavage, a mutation commonly used for antibodies. Then, in one aspect, the bifunctional molecule comprises at least one additional amino acid substitution consisting of K444A.

Optionally, the bifunctional molecule comprises additional cysteine residues at the C-terminal domain of the Fc domain to create additional disulfide bonds and potentially limit the flexibility of the bifunctional molecule.

In one aspect, the bifunctional molecule comprises a heavy chain constant domain of SEQ ID NO:39 or 52 and/or a light chain constant domain of SEQ ID NO:40, in particular a heavy chain constant domain or Fc domain of SEQ ID NO:39 or 52 and a light chain constant domain of SEQ ID NO:40, in particular as disclosed in Table H below.

Examples of heavy chain constant domains and light chain constant domains suitable for the bifunctional molecules according to the invention.

In a specific aspect, the bifunctional molecule according to the invention comprises a heterodimer of an Fc domain comprising a "knob-to-socket" modification as described above. Preferably, such Fc domain is an IgG1 or IgG4 Fc domain such as described above, even more preferably an IgG1 Fc domain comprising a mutation such as disclosed above N297A.

For example, the first Fc strand is a "mortar" or H strand and comprises the substitutions T366S/L368A/Y407V/Y349C and optionally N297A, and the second Fc strand is a "pestle" or K strand and comprises the substitutions T366W/S354C and optionally N297A. Preferably, the first Fc strand is the "mortar" or H strand and comprises the substitutions T366S/L368A/Y407V/Y349C and N297A, and the second Fc strand is the "pestle" or K strand and comprises the substitutions T366W/S354C and N297A. More specifically, the second Fc chain may comprise or consist of SEQ ID NO. 75 and/or the first Fc chain may comprise or consist of SEQ ID NO. 77.

More specifically, IL-7m according to the invention is linked to the pestle and/or mortar chain of the heterodimeric Fc domain. Thus, a bifunctional molecule according to the invention may comprise a single IL-7m linked to the mortar or pestle chain of an Fc domain. Preferably, the bifunctional molecule according to the invention comprises a single IL-7m linked to the mortar chain of the Fc domain.

In a first aspect, the bifunctional molecule comprises IL-7m linked to the C-terminus of the pestle chain of an Fc domain, such a pestle chain of an Fc domain being linked to an antigen binding domain.

In a second aspect, the bifunctional molecule comprises IL-7m linked to the C-terminus of the mortar chain of an Fc domain, the mortar chain of such Fc domain being linked at its N-terminus to an antigen binding domain.

Optionally, the bifunctional molecule comprises a single IL-7m linked to the C-terminus of the mortar chain of the Fc domain, wherein the bifunctional molecule comprises only a single antigen binding domain linked to the N-terminus of the mortar chain of the Fc domain. In such aspects, the loop domain lacks IL-7m and the antigen binding domain.

Optionally, the bifunctional molecule comprises a single IL-7m linked to the C-terminus of the pestle chain of the Fc domain, wherein the bifunctional molecule comprises only a single antigen binding domain linked to the N-terminus of the pestle chain of the Fc domain. In such aspects, the mortar chain domain lacks IL-7m and antigen binding domain.

Accordingly, one object of the present invention relates to a polypeptide comprising from the N-terminus to the C-terminus an antigen binding domain (or at least a portion thereof corresponding to a heavy chain), an Fc chain (pestle or mortar Fc chain), preferably the mortar chain of the Fc domain, and IL-7 m. The complementary strand comprises a complementary Fc strand lacking IL-7m and an antigen binding domain, preferably the pestle chain of the Fc domain.

In a very specific aspect, the bifunctional molecule targets PD-1 and comprises:

(a) Comprising or consisting of a heavy chain selected from the group consisting of the amino acid sequences of SEQ ID NOs 29, 30, 31, 32, 33, 34 or 36, optionally having one, two or three modifications selected from substitutions, additions, deletions and any combination thereof at any position other than positions 7, 16, 17, 20, 33, 38, 43, 46, 62, 63, 65, 69, 73, 76, 78, 80, 84, 85, 88, 93, 95, 96, 97, 98, 100, 101, 105, 106 and 112, and substitutions corresponding to mortar or pestle chains, preferably mortar chains, more particularly as disclosed in table F, more particularly T S/L40V/Y47V/Y363C or T363C 40V/Y363C, V346C, optionally as disclosed in table F, in any of SEQ ID NOs 29, 30, 31, 32, 33, 34, 35 or 36, 29, 30, 31, 33, 34, 35 or 36;

(b) A light chain comprising or consisting of the amino acid sequence of SEQ ID No. 37 or SEQ ID No. 38, optionally having one, two or three modifications selected from the group consisting of substitutions, additions, deletions and any combination thereof at any position other than positions 3, 4, 7, 14, 17, 18, 28, 29, 33, 34, 39, 42, 44, 50, 81, 88, 94, 97, 99 and 105 of SEQ ID No. 37 or SEQ ID No. 38.

In another aspect, the bifunctional molecule comprises or consists of any of the following combinations of heavy Chain (CH) and light Chain (CL):

the heavy chain comprises a substitution corresponding to a mortar or pestle chain, preferably a mortar chain, more particularly as disclosed in table F, in particular in any of SEQ ID NOs 29, 30, 31, 32, 33, 34, 35 or 36, in particular T366S/L368A/Y407V/Y349C or T366W/S354C, preferably T366S/L368A/Y407V/Y349C and optionally N297A of any of SEQ ID NOs 29, 30, 31, 32, 33, 34, 35 or 36, the position of the substitution being defined according to EU numbering.

In a very specific aspect, the bifunctional molecule targets PD-1 and comprises a light chain comprising or consisting of SEQ ID NO. 37 or 38.

Thus, a bifunctional molecule may comprise a heavy chain comprising any of SEQ ID NOs 29, 30, 31, 32, 33, 34, 35 and 36, the Fc chain optionally being modified to promote heterodimerization of the Fc chain to form a heterodimerized Fc domain. More specifically, the heavy chain comprises a substitution corresponding to a mortar or pestle chain, preferably a mortar chain, more specifically as disclosed in table F, in particular T366S/L368A/Y407V/Y349C or T366W/S354C, preferably T366S/L368A/Y407V/Y349C, and optionally N297A of any of SEQ ID nos. 29, 30, 31, 32, 33, 34, 35 or 36, the positions of the substitutions being defined according to EU numbering. The heavy chain is linked to IL-7m at its C-terminus, optionally via a linker.

Preferred structure

In a particular aspect, the molecule comprises a first monomer comprising an antigen binding domain covalently linked, optionally via a peptide linker, to a first Fc chain, optionally via a peptide linker, to an IL-7 variant, and a second monomer comprising a complementary second Fc chain, preferably free of antigen binding domain and IL-7 variant, said first and second Fc chains forming a dimeric Fc domain. Optionally, the dimeric Fc domain is a heterodimeric Fc domain. More specifically, the molecule comprises a first monomer comprising an antigen binding domain covalently linked, optionally via a peptide linker, to the N-terminus of a first heterodimeric Fc chain, optionally via a peptide linker, covalently linked via its C-terminus to an IL-7 variant, and a second monomer comprising a complementary second heterodimeric Fc chain free of antigen binding domain and IL-7 variant, preferably free of any other molecule. Still more particularly, the molecule comprises a first monomer comprising an antigen binding domain covalently linked by its C-terminus to the N-terminus of a first heterodimeric Fc chain covalently linked by its C-terminus to the N-terminus of an IL-7 variant, optionally via a peptide linker, and a second monomer; and the second monomer comprises a complementary second heterodimeric Fc chain that is free of antigen binding domains and IL-7 variants, preferably free of any other molecules. For example, such a molecule is shown in fig. 1 as "construct 3".

In particular, the bifunctional molecules according to the invention comprise a single anti-PD-1 antigen binding domain and a single IL-7W142H variant (this construct is also referred to as anti-PD-1 x 1IL-7W142H x 1). In particular, such constructs comprise a variable heavy chain (VH) as defined in SEQ ID NO. 24 and a variable light chain (VL) as defined in SEQ ID NO. 28. The molecule comprises a heavy chain as defined in SEQ ID NO. 83 which binds IL-7W142H, an Fc region as defined in SEQ ID NO. 75 and a light chain as defined in SEQ ID NO. 80.

In another aspect, the bifunctional molecule according to the invention comprises a single anti-PD-1 antigen binding domain and a single IL-7W142H variant (this construct is also referred to as anti-PD-1 x 1IL-7W142H x 1). In particular, such constructs comprise a variable heavy chain (VH) as defined in SEQ ID NO. 24 and a variable light chain (VL) as defined in SEQ ID NO. 88 or 90.

In one aspect, the invention relates to a bifunctional molecule comprising a single antigen binding domain and a single IL-7 variant, wherein:

-the bifunctional molecule comprises a first monomer comprising an antigen binding domain covalently linked to the N-terminus via the C-terminus of the first Fc chain, optionally via a peptide linker, and a second monomer comprising a complementary second Fc chain free of antigen binding domain and IL-7 variant;

-i) an IL-7 variant is covalently linked to the C-terminus of the first Fc chain, optionally through a peptide linker; or ii) a single antigen binding domain comprises a heavy variable chain and a light variable chain and the IL-7 variant is covalently linked to the C-terminus of the light chain;

-the antigen binding domain binds to PD-1; and

-an IL-7 variant exhibiting at least 75% identity with wild-type human IL-7 (wth-IL-7), said wild-type human IL-7 (wth-IL-7) comprising or consisting of the amino acid sequence set forth in SEQ ID No. 1, and IL-7 variant i) decreasing the affinity of the IL-7 variant for IL-7 receptor (IL-7R) compared to the affinity of wth-IL-7 for IL-7R, and ii) improving the pharmacokinetics of a bifunctional molecule comprising the IL-7 variant compared to a bifunctional molecule comprising said wth-IL-7.

In particular, the IL-7 variant comprises at least one amino acid mutation selected from the group consisting of: (i) W142G, W142A, W142V, W142C, W142L, W142I, W142M, W142H, W Y and W142F, preferably W142H, W142F or W142Y, (ii) C2S-C141S and C47S-C92S, C S-C141S and C34S-C129S, or C47S-C92S and C34S-C129S, (iii) D74E, D Q or D74N, iv) Q11E, Y12F, M17L, Q E and/or K81R; or any combination thereof, the amino acid numbers of which are as set forth in SEQ ID NO:1, preferably the amino acid substitution W142H, even more preferably as set forth in SEQ ID NO: 5.

In another aspect, the invention relates to a bifunctional molecule comprising a single antigen binding domain and a single IL-7 variant

Wherein:

-the bifunctional molecule comprises a first monomer comprising an antigen binding domain covalently linked to the N-terminus via the C-terminus of a first Fc chain, optionally via a peptide linker, and a second monomer comprising a complementary second Fc chain free of antigen binding domain and IL-7 variant;

an antigen binding domain as described in the paragraph above "antigen binding domain targeting PD-1 on immune cells";

IL7 is as described in the "IL-7 and IL-7 variants" paragraphs above;

the Fc domain is as described in the "Fc domain" paragraph above;

peptide linker as described in the above "peptide linker" paragraph.

Preferably, the peptide linker is (GGGGS) ₃ Or GGGGSGGGGSGGGGS or as defined in SEQ ID NO: 70.

Preferably, the Fc domain is derived from human IgG1 or IgG4. The first Fc strand is a mortar or H strand and comprises the substitutions T366S/L368A/Y407V/Y349C and optionally N297A, and the second Fc strand is a pestle or K strand and comprises the substitutions T366W/S354C and optionally N297A. Preferably, the Fc strand is the mortar or H strand and comprises the substitutions T366S/L368A/Y407V/Y349C and N297A, and the second Fc strand is the pestle or K strand and comprises the substitutions T366W/S354C and N297A. More preferably, the second Fc chain comprises or consists of SEQ ID NO. 75 and/or the first Fc chain comprises or consists of SEQ ID NO. 77.

Preferably, IL-7 comprises the amino acid substitution W142H, the amino acid numbers of which are shown in SEQ ID NO. 1, in particular as defined in SEQ ID NO. 5.

Preferably, the antigen binding domain is derived from an antibody selected from the group consisting of: palbociclib, nivolumab, pidil mab, cimetidine Li Shan, carlizumab, AUNP12, AMP-224, age-2034, BGB-a317, spatazumab, MK-3477, SCH-900475, PF-06801591, JNJ-63723283, ji Nuoli mu mab, LZM-009, BCD-100, SHR-1201, BAT-1306, AK-103, MEDI-0680, MEDI0608, JS001, BI-754091, CBT-501, incsler 1210, TSR-042, GLS-010, AM-0001, STI-1110, age 2034, MGA012 or IBI308, 5C4, 17D8, 2D3, 4H1, 4a11, 7D3 and 5F4. More preferably, the antigen binding domain comprises or consists essentially of: (i) A heavy chain comprising CDR1 of SEQ ID NO:51, CDR2 of SEQ ID NO:53 and CDR3 of SEQ ID NO:55, 56, 57, 58, 59, 60, 61 or 62; and (ii) a light chain comprising CDR1 of SEQ ID NO. 64 or 65, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16. Even more preferably, the antigen binding domain comprises or consists essentially of: (i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 61; (ii) A light chain comprising CDR1 of SEQ ID NO. 65, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16. Preferably, the antigen binding domain comprises or consists essentially of: (a) Comprising SEQ ID NO 18, 19, 20, 21, 22, 23, 24 or 25, preferably SEQ ID NO:24 or a heavy chain variable region (VH) consisting of or consisting of the same; and (b) a light chain variable region (VL) comprising or consisting of the amino acid sequence of SEQ ID NO. 27, SEQ ID NO. 28, SEQ ID NO. 88 or SEQ ID NO. 99, preferably SEQ ID NO. 28. Preferably, the antigen binding domain comprises or consists essentially of: (a) A heavy chain variable region (VH) comprising SEQ ID NO 18, 19, 20, 21, 22, 23, 24 or 25, preferably SEQ ID NO:24 or consists of the amino acid sequence of seq id no; (b) Comprising or consisting of the amino acid sequence of SEQ ID NO. 27 or SEQ ID NO. 28, preferably SEQ ID NO. 28.

In a specific aspect, the bifunctional molecule according to the invention comprises an anti-PD-1 antigen-binding domain comprising or consisting essentially of the heavy chain variable region (VH) of SEQ ID NO:24 and the light chain variable region (VL) of SEQ ID NO:28, and an IL-7 variant comprising the amino acid substitution W142H, the amino acid numbering as shown in SEQ ID NO:1, preferably as defined in SEQ ID NO: 5.

In particular, the bifunctional molecules according to the invention comprise (i) an anti-PD-1 antigen-binding domain comprising or essentially consisting of the heavy chain variable region (VH) of SEQ ID NO:24 and the light chain variable region (VL) of SEQ ID NO:28, 88 or 99,

(ii) IL-7 variants comprise or consist essentially of the sequence defined in SEQ ID 5,

(iii) The second Fc chain comprises or consists of SEQ ID NO 75 and/or the first Fc chain comprises or consists of SEQ ID NO 77 and

(iv) Optionally, the peptide linker comprises or consists essentially of SEQ ID NO. 70.

In particular, the bifunctional molecules according to the invention comprise (i) an anti-PD-1 antigen-binding domain comprising or essentially consisting of the heavy chain variable region (VH) of SEQ ID NO:24 and the light chain variable region (VL) of SEQ ID NO:28,

In a very specific aspect, the bifunctional molecule comprises a light chain comprising or consisting of SEQ ID NO:38 and a heavy chain comprising SEQ ID NO:35, the Fc chain optionally being modified to promote heterodimerization of the Fc chain to form a heterodimerized Fc domain. In one aspect, the heavy chain is linked to IL-7m at its C-terminus, optionally via a linker. In alternative aspects, the light chain is linked to IL-7m at its C-terminus, optionally via a linker.

In a very specific aspect, the bifunctional molecule may comprise a second monomer of SEQ ID NO:75 and a first monomer comprising an Fc chain of SEQ ID NO:77, which is linked at the N-terminus to an antigen binding domain (e.g., SEQ ID NO: 79), optionally via a linker. More preferably, the bifunctional molecule may comprise a second monomer of SEQ ID NO:75 and a first monomer comprising an Fc chain of SEQ ID NO:77, optionally linked at the N-terminus to an antigen binding domain (e.g., SEQ ID NO: 79) by a linker, and at the C-terminus to any IL-7m disclosed herein, optionally by a linker.

Optionally, when IL-7m is an IL-7 variant, the bifunctional molecule may comprise a second monomer of SEQ ID NO:75, a first monomer of SEQ ID NO:83 and a third monomer of SEQ ID NO:37, 38 or 80, preferably SEQ ID NO:38 or 80.

Optionally, when IL-7m is an IL-7 variant, the bifunctional molecule may comprise a second monomer of SEQ ID NO:75, a first monomer of SEQ ID NO:84 and a third monomer of SEQ ID NO:37, 38 or 80 (preferably SEQ ID NO:38 or 80), which is linked at its end optionally via a linker to an IL-7 variant, in particular a variant of any of SEQ ID NO:2-15, in particular SEQ ID NO:5.

In another very specific aspect, the bifunctional molecule may comprise a second monomer of SEQ ID NO:77 and a first monomer comprising an Fc chain of SEQ ID NO:75, optionally linked at the N-terminus to an antigen binding domain (e.g., SEQ ID NO: 79) via a linker, and at the C-terminus to any IL-7m disclosed herein, optionally via a linker.

In another very specific aspect, the bifunctional molecule may comprise a second monomer of SEQ ID NO:77, a first monomer comprising an Fc chain SEQ ID NO:75, optionally linked N-terminally to an antigen binding domain (e.g. SEQ ID NO: 79) via a linker, and a third monomer of SEQ ID NO:37, 38 or 80, preferably SEQ ID NO:38 or 80, optionally linked at its end to any IL-7m disclosed herein via a linker.

In particular, IL-7m comprises or consists essentially of SEQ ID NO. 1 or a variant thereof having at least 80, 85, 90, 91, 92, 93, 94, 95, 96, 97, 98 or 99% identity thereto or 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 modifications relative to the wild type protein selected from the group consisting of additions, deletions, substitutions and combinations thereof.

Optionally, the bifunctional molecule may comprise a second monomer of SEQ ID NO. 77, a first monomer of SEQ ID NO. 82 and a third monomer of SEQ ID NO. 37, 38 or 80, preferably SEQ ID NO. 38 or 80.

In a very specific aspect, the bifunctional molecule according to the invention comprises a first monomer of SEQ ID NO. 75, a second monomer of SEQ ID NO. 83 and a third monomer of SEQ ID NO. 80, 100 or 101. Preferably, the bifunctional molecule according to the invention comprises a first monomer of SEQ ID NO. 75, a second monomer of SEQ ID NO. 83 and a third monomer of SEQ ID NO. 80.

Preparation of bifunctional molecules-nucleic acid molecules encoding the bifunctional molecules of the invention, recombinant expression vectors and host cells comprising the same

To produce the bifunctional molecules according to the invention, the nucleic acid sequences or groups of nucleic acid sequences encoding the bifunctional molecules are subcloned into one or more expression vectors, in particular by mammalian cells. Such vectors are commonly used to transfect mammalian cells. General techniques for producing molecules comprising antibody sequences are described by Coligan et al (eds.), current protocols in immunology, at pp.10.19.1-10.19.11 (Wiley Interscience 1992), the contents of which are incorporated herein by reference, and comments related to molecular production in "Antibody engineering: a practical guide" from W.H. Freeman and Company (1992) are dispersed in each text.

Generally, the method comprises the steps of:

(1) Transfecting or transforming a suitable host cell with a polynucleotide encoding a recombinant bifunctional molecule of the invention or a vector comprising the polynucleotide;

(2) Culturing the host cell in a suitable medium; and

(3) Optionally isolating or purifying the bifunctional molecule from the culture medium or the host cell.

The invention further relates to nucleic acids encoding the bifunctional molecules as described above, vectors, preferably expression vectors, transformed genetically engineered host cells with the vectors of the invention or directly with sequences encoding recombinant bifunctional molecules, comprising the nucleic acids of the invention, and methods for producing the bifunctional molecules of the invention by recombinant techniques.

Nucleic acids, vectors, and host cells are described in more detail below.

Nucleic acid sequences

The invention also relates to a nucleic acid molecule encoding a bifunctional molecule as defined above or a set of nucleic acid molecules encoding a bifunctional molecule as defined above. Nucleic acids encoding the bifunctional molecules disclosed herein may be amplified by any technique known in the art, such as PCR. Such nucleic acids can be readily isolated and sequenced using conventional procedures.

In particular, nucleic acid molecules encoding the bifunctional molecules defined herein include:

-a first nucleic acid molecule encoding a first monomer comprising an antigen binding domain covalently linked, optionally via a peptide linker, to a first Fc chain, said first Fc chain being covalently linked, optionally via a peptide linker, to IL7m, and

a second nucleic acid molecule encoding a second monomer comprising a complementary second Fc strand,

-a third nucleic acid molecule encoding a light chain of an antigen binding domain.

In another aspect, a nucleic acid molecule encoding a bifunctional molecule as defined herein comprises:

a first nucleic acid molecule encoding a first monomer comprising an antigen binding domain covalently linked to a first Fc chain, optionally via a peptide linker,

-a second nucleic acid molecule encoding a second monomer comprising a complementary second Fc chain, and

-a third nucleic acid molecule encoding a light chain of an antigen binding domain, said light chain being covalently linked to an IL7 variant according to the invention, optionally through a peptide linker.

In one embodiment, the nucleic acid molecule is an isolated, in particular a non-natural, nucleic acid molecule.

Specifically, the nucleic acid encodes IL-7m having the amino acid sequence shown in SEQ ID NO. 2 through 15.

In another aspect, a nucleic acid molecule encoding a bifunctional molecule as defined herein comprises a variable heavy domain having the sequence shown in SEQ ID NO:73 and/or a variable light domain having the sequence shown in SEQ ID NO: 74.

Carrier body

In a further aspect, the invention relates to a vector comprising a nucleic acid molecule or group of nucleic acid molecules as defined above.

As used herein, a "vector" is a nucleic acid molecule that serves as a vector for transferring genetic material into a cell. The term "vector" encompasses plasmids, viruses, cosmids, and artificial chromosomes. In general, an engineered vector comprises an origin of replication, a multiple cloning site, and a selectable marker. The vector itself is typically a nucleotide sequence, typically a DNA sequence, comprising an insert (transgene) and a larger sequence that serves as the "backbone" of the vector. In addition to the transgene insert and backbone, modern vectors may contain other features: promoters, gene markers, antibiotic resistance, reporter genes, targeting sequences, and protein purification tags. Vectors known as expression vectors (expression constructs) are used exclusively for expressing transgenes in target cells and typically have control sequences.

The person skilled in the art can clone the nucleic acid molecule encoding the bifunctional molecule, the fusion protein, into a vector and then transform it into a host cell. These methods include in vitro recombinant DNA techniques, DNA synthesis techniques, in vivo recombinant techniques, and the like. Methods known to those skilled in the art can be used to construct expression vectors containing bifunctional molecules, nucleic acid sequences of variants described herein, and appropriate regulatory components for transcription/translation.

Accordingly, the present invention also provides a recombinant vector comprising a nucleic acid molecule encoding a bifunctional molecule of the invention. In a preferred aspect, the expression vector further comprises a promoter and a nucleic acid sequence encoding a secretion signal peptide, and optionally at least one drug resistance gene for screening. The expression vector may also contain ribosome binding sites for initiating translation, transcription terminators and the like.

Suitable expression vectors typically contain (1) prokaryotic DNA elements encoding bacterial origins of replication and antibiotic resistance markers to provide for the growth and selection of the expression vector in a bacterial host; (2) Eukaryotic DNA elements that control transcription initiation, such as promoters; (3) DNA elements that control transcript processing, such as transcription termination/polyadenylation sequences.

Expression vectors can be introduced into host cells using a variety of techniques, including calcium phosphate transfection, liposome-mediated transfection, electroporation, and the like. Preferably, transfected cells are selected and propagated in which the expression vector is stably integrated into the host cell genome to produce a stable transformant.

Host cells

In a further aspect, the invention relates to a host cell comprising a vector or a nucleic acid molecule or a group of nucleic acid molecules as defined above, e.g. for the purpose of bifunctional molecule production.

As used herein, the term "host cell" is intended to include any individual cell or cell culture that may or may not be the recipient of vectors, exogenous nucleic acid molecules and polynucleotides encoding bifunctional molecules according to the present invention. The term "host cell" is also intended to include progeny or potential progeny of a single cell. Suitable host cells include prokaryotic or eukaryotic cells, and also include, but are not limited to, bacterial, yeast, fungal, plant and animal cells such as insect cells and mammalian cells, e.g., murine, rat, rabbit, macaque or human.

Suitable host cells are in particular eukaryotic host cells which provide suitable post-translational modifications such as glycosylation. Preferably, such suitable eukaryotic host cells may be fungi, such as Pichia pastoris, saccharomyces cerevisiae, schizosaccharomyces pombe; insect cells such as Mythimna separate; plant cells such as tobacco, and mammalian cells such as BHK cells, 293 cells, CHO cells, NSO cells and COS cells.

Preferably, the host cell of the invention is selected from the group consisting of CHO cells, COS cells, NSO cells and HEK cells.

The host cell then stably or transiently expresses the bifunctional molecules of the invention. Such expression methods are known to those skilled in the art.

Also provided herein are methods of producing the bifunctional molecules. The method comprises culturing a host cell comprising a nucleic acid encoding the bifunctional molecule described above under conditions suitable for its expression, and optionally recovering the bifunctional molecule from the host cell (or host cell culture medium). In particular, for recombinant production of a bifunctional molecule, a nucleic acid encoding a bifunctional molecule, e.g. as described above, is isolated and inserted into one or more vectors for further cloning and/or expression in a host cell. The bifunctional molecule is then isolated and/or purified by any method known in the art. Such methods include, but are not limited to, conventional renaturation treatment, protein precipitant treatment (e.g., salt precipitation), centrifugation, osmotic cell lysis, sonication, ultracentrifugation, molecular sieve or gel chromatography, adsorption chromatography, ion exchange chromatography, HPLC, any other liquid chromatography, and combinations thereof. As described in Coligan, for example, bifunctional molecular separation techniques may specifically include affinity chromatography using Protein-A Sepharose, size exclusion chromatography, and ion exchange chromatography. Protein a is preferably used to isolate the bifunctional molecules of the invention.

Pharmaceutical compositions and methods of administration thereof

The invention also relates to pharmaceutical compositions comprising the bifunctional molecules described herein, nucleic acid molecules as described above, groups of nucleic acid molecules, vectors and/or host cells, preferably as active ingredients or compounds. The formulation may be sterilized and, if desired, mixed with adjuvants, such as pharmaceutically acceptable carriers, excipients, salts, antioxidants and/or stabilizers, which do not deleteriously interact with the bifunctional molecules of the invention, the nucleic acids of the invention, the vectors and/or the host cells and which do not impart any undesired toxicological effects. Optionally, the pharmaceutical composition may further comprise an additional therapeutic agent.

In particular, the pharmaceutical compositions according to the present invention may be formulated for any conventional route of administration, including topical, enteral, oral, parenteral, intranasal, intravenous, intramuscular, subcutaneous or intraocular administration, and the like. For ease of administration, the bifunctional molecules described herein may be formulated into pharmaceutical compositions for in vivo administration. Methods of preparing such compositions have been described in the art (see, e.g., remington: the Science and Practice ofPharmacy, lippincott Williams & Wilkins,21st edition (2005).

Pharmaceutical compositions may be prepared by mixing bifunctional molecules of the desired purity with optional pharmaceutically acceptable carriers, excipients, antioxidants and/or stabilizers in the form of lyophilized formulations or aqueous solutions. Such suitable carriers, excipients, antioxidants and/or stabilizers are well known in the art and have been described, for example, in Remington's Pharmaceutical Sciences 16th edition,Osol,A.Ed (1980).

To facilitate delivery, any bifunctional molecule or nucleic acid encoding the same may be conjugated to a chaperone. The chaperone agent may be a naturally occurring substance, such as a protein (e.g., human serum albumin, low density lipoprotein or globulin), a carbohydrate (e.g., dextran, pullulan, chitin, chitosan, inulin, cyclodextrin or hyaluronic acid), or a lipid. It may also be a recombinant or synthetic molecule, such as a synthetic polymer, e.g. a synthetic polypeptide.

The pharmaceutical compositions according to the invention may be formulated to release the active ingredient (e.g. the bifunctional molecule of the invention) substantially immediately after administration or at any predetermined time or period after administration. In some aspects, the pharmaceutical compositions may employ a time release, delayed release, and sustained release delivery system such that delivery of the composition occurs prior to sensitization of the site to be treated and for a time sufficient to cause sensitization of the site to be treated. Methods known in the art may be used to prevent or minimize the release and absorption of the composition until it reaches the target tissue or organ, or to ensure timed release of the composition. Such systems can avoid repeated administration of the composition, thereby increasing the convenience of the subject and the physician.

It will be appreciated by those skilled in the art that the formulation of the present invention may be isotonic with human blood, i.e., the formulation of the present invention has substantially the same osmotic pressure as human blood. Such isotonic formulations typically have an osmotic pressure of about 250mOSm to about 350 mOSm. Isotonicity can be measured by, for example, a vapor pressure or ice-cold osmometer.

Pharmaceutical compositions must generally be sterile and stable under the conditions of manufacture and storage. Prevention of the presence of microorganisms may be ensured by sterilization procedures (e.g., by microfiltration) and/or by inclusion of various antibacterial and antifungal agents

The amount of active ingredient that can be combined with the carrier material to produce a single dosage form will vary depending upon the subject being treated and the particular mode of administration. The amount of active ingredient that can be combined with the carrier material to produce a single dosage form is generally the amount of the composition that produces a therapeutic effect.

Subject, regimen and administration

The present invention relates to a bifunctional molecule disclosed herein, a nucleic acid or vector encoding the same, a host cell or a pharmaceutical composition for use as a medicament or for treating a disease or for administration in a subject or as a medicament. It also relates to a method for treating a disease or disorder in a subject comprising administering to the subject a therapeutically effective amount of a pharmaceutical composition or a bifunctional molecule.

The subject to be treated may be a human, in particular a human in the prenatal stage, a neonate, a child, an infant, a adolescent or an adult, in particular an adult of at least 30 years, 40 years, preferably an adult of at least 50 years, still more preferably an adult of at least 60 years, even more preferably an adult of at least 70 years.

In particular aspects, the subject may be immunosuppressed or immunocompromised.

Conventional methods known to those of ordinary skill in the medical arts may be used to administer the bifunctional molecules or pharmaceutical compositions disclosed herein to a subject, depending on the type of disease to be treated or the site of the disease, for example, orally, parenterally, enterally, by inhalation spray, topically, rectally, nasally, buccally, vaginally, or by implanted reservoir administration. Preferably, the bifunctional molecule or pharmaceutical composition is administered by subcutaneous, intradermal, intravenous, intramuscular, intra-articular, intra-arterial, intra-synovial, intratumoral, intrasternal, intrathecal, intralesional and intracranial injection or infusion techniques.

The form, route of administration and dosage of administration of the pharmaceutical composition or bifunctional molecule of the invention may be adapted by the person skilled in the art according to the type and severity of the infection and the patient, in particular his age, weight, body shape, sex and/or general physical condition. The compositions of the present invention may be administered in a variety of ways depending on whether local or systemic treatment is desired.

For the treatment of diseases

The bifunctional molecules, nucleic acids, vectors, host cells, compositions and methods of the invention have a number of uses and applications in vitro and in vivo. In particular, any of the bifunctional molecules, nucleic acid molecules, sets of nucleic acid molecules, vectors, host cells, or pharmaceutical compositions provided herein may be used in a method of treatment and/or for therapeutic purposes.

The invention also relates to a bifunctional molecule, a nucleic acid or a vector encoding the same, or a pharmaceutical composition comprising the same, for use in the treatment of a disorder and/or a disease in a subject and/or as a medicament or vaccine. It also relates to a bifunctional molecule as described herein; use of a nucleic acid or encoding such a vector or comprising such a pharmaceutical composition for treating a disease and/or disorder in a subject. Finally, it relates to a method of treating a disease or disorder in a subject comprising administering to the subject a therapeutically effective amount of a pharmaceutical composition or a bifunctional molecule, or a nucleic acid or a vector encoding such a nucleic acid.

In one aspect, the present invention relates to a method of treating a disease and/or disorder selected from cancer, infectious disease and chronic viral infection in a subject in need thereof, comprising administering to said subject an effective amount of a bifunctional molecule or a pharmaceutical composition as defined above. Examples of such diseases will be described in more detail below.

In one aspect, the method of treatment comprises: (a) identifying a patient in need of treatment; and (b) administering to the patient a therapeutically effective amount of a bifunctional molecule, nucleic acid, vector, or pharmaceutical composition described herein.

The subject in need of treatment may be a person suffering from, facing or suspected of suffering from a disease. Such patients may be identified by routine medical examination.

In another aspect, the bifunctional molecules disclosed herein may be administered to a subject, e.g., in vivo, to enhance immunity, preferably for treating a disorder and/or disease. Accordingly, in one aspect, the invention provides a method of modifying an immune response in a subject comprising administering to the subject a bifunctional molecule, nucleic acid, vector or pharmaceutical composition of the invention, such that the immune response in the subject is modified. Preferably, the immune response is enhanced, increased, stimulated or upregulated. The bifunctional molecule or pharmaceutical composition may be used to enhance an immune response, such as T cell activation, in a subject in need of treatment. In particular embodiments, the bifunctional molecule or pharmaceutical composition may be used to reduce T cell depletion or reactivate depleted T cells.

The invention provides, inter alia, a method of enhancing an immune response in a subject, comprising administering to the subject a therapeutically effective amount of any one of a bifunctional molecule, a nucleic acid, a vector, or a pharmaceutical composition comprising the same, thereby enhancing the immune response in the subject. In particular embodiments, the bifunctional molecule or pharmaceutical composition may be used to reduce T cell depletion or reactivate depleted T cells.

Bifunctional molecules comprising IL-7 variants according to the invention target CD127+ immune cells, in particular CD127+ T cells. Such cells can be found in the following areas of particular interest: the resident lymphocytes in the lymph nodes (mostly cells beside the cortex, occasionally in the hair follicles), the resident lymphoid cells in the tonsils (interfollicular region), the spleen (mostly in periarterial lymph sheath (PALS) of the white pulp, some dispersed cells in the red pulp), the thymus (mostly in the medulla; also in the cortex), the bone marrow (dispersed distribution), GALT (intestinal-related lymphoid tissue in the whole digestive tract (stomach, duodenum, jejunum, ileum, cecum, colon, rectum), in MALT (mucosa-related lymphoid tissue) of the gall bladder. The bifunctional molecules of the invention are therefore of particular interest for the treatment of diseases located in or involving these regions, in particular cancer.

In a particular aspect, the bifunctional molecule comprises an IL-7 variant, in particular W142H, and an antigen binding domain that binds to and antagonizes PD-1.

Such bifunctional molecules and pharmaceutical compositions comprising the same are useful in patients, particularly patients suffering from cancer, for increasing tumor-infiltrating lymphocytes (TIL), protecting T lymphocytes from apoptosis, inducing/improving T memory responses, eliminating T-reg inhibition and/or Treg inhibitory activity, restoring proliferation and/or maintaining fully depleted T cells, particularly depleted tumor-infiltrating lymphocytes.

Such bifunctional molecules and pharmaceutical compositions comprising the same may be used for the manufacture of a medicament for increasing tumor-infiltrating lymphocytes (TIL), protecting T lymphocytes from apoptosis, inducing/improving T memory responses, eliminating T-reg inhibition and/or the inhibitory activity of tregs, restoring proliferation and/or maintaining fully depleted T cells, in particular depleted tumor-infiltrating lymphocytes, in a patient, in particular a patient suffering from cancer.

The invention also relates to a method for increasing tumor-infiltrating lymphocytes (TIL), protecting T lymphocytes from cell death, inducing/improving T memory responses, eliminating T-reg inhibition and/or inhibitory activity of tregs, restoring proliferation and/or maintaining completely depleted T cells, in particular depleted tumor-infiltrating lymphocytes, in a patient, in particular a patient suffering from cancer, comprising administering to the patient a therapeutically effective amount of a bifunctional molecule comprising an IL-7 variant, in particular W142H, and an antigen binding domain that binds and antagonizes PD-1, in particular any such specific molecule disclosed herein.

Cancer of the human body

In another aspect, the invention provides the use of a bifunctional molecule or pharmaceutical composition disclosed herein in the manufacture of a medicament for treating cancer, e.g., for inhibiting tumor cell growth in a subject.

The term "cancer" as used herein is defined as a disease characterized by the rapid and uncontrolled growth of abnormal cells. Cancer cells can spread locally or through the blood stream and lymphatic system to other parts of the body.

Thus, in one aspect, the invention provides a method of treating cancer in a subject, for example a method for inhibiting the growth of tumor cells, comprising administering to the subject a therapeutically effective amount of a bifunctional molecule or a pharmaceutical composition according to the invention. In particular, the invention relates to the use of bifunctional molecules to treat subjects to inhibit the growth of cancer cells.

In one aspect of the disclosure, the cancer to be treated is associated with depleted T cells.

Any suitable cancer that can be treated with the provided herein can be a hematopoietic cancer or a solid cancer. Such cancers include cancer, cervical cancer, colorectal cancer, esophageal cancer, gastric cancer, gastrointestinal cancer, head and neck cancer, renal cancer, liver cancer, lung cancer, lymphoma, glioma, mesothelioma, melanoma, gastric cancer, cancer of the urinary tract, environmentally induced cancers, and any combination of said cancers. In addition, the invention includes refractory or recurrent malignant tumors. Preferably, the cancer to be treated or prevented is selected from metastatic or non-metastatic, melanoma, malignant mesothelioma, non-small cell lung cancer, renal cell carcinoma, hodgkin's lymphoma, head and neck cancer, urothelial cancer, colorectal cancer, hepatocellular carcinoma, small cell lung cancer, metastatic mercker cell carcinoma, gastric or gastroesophageal cancer, and cervical cancer.

In a particular aspect, the cancer is a hematological malignancy or a solid tumor. The cancer may be selected from the group consisting of hematological lymphomas, angioimmunoblastic T cell lymphomas, myelodysplastic syndromes, and acute myelogenous leukemia.

In particular aspects, the cancer is a cancer induced by a virus or associated with an immunodeficiency. Such cancers may be selected from the following: kaposi's sarcoma (e.g., associated with kaposi's sarcoma herpes virus); cervical cancer, anal cancer, penile cancer and vulvar squamous cell carcinoma, and oropharyngeal cancer (e.g., associated with human papillomavirus); b-cell non-hodgkin lymphomas (NHL), including diffuse large B-cell lymphomas, burkitt's lymphomas, plasmablasts, primary central nervous system lymphomas, HHV-8 primary exudative lymphomas, classical hodgkin lymphomas, and lymphoproliferative diseases (e.g., associated with epstein-barr virus (EBV) and/or kaposi's sarcoma herpes virus); hepatocellular carcinoma (e.g., associated with hepatitis b and/or hepatitis c virus); merck cell carcinoma (e.g., associated with merck cytodoloma virus (MPV); and cancers associated with Human Immunodeficiency Virus (HIV) infection.

Preferred treatments for cancer include cancers that are generally responsive to immunotherapy. Alternatively, the preferred treatment for cancer is cancer that is not responsive to immunotherapy.

Infectious disease

The bifunctional molecules, nucleic acids, nucleic acid sets, vectors, host cells or pharmaceutical compositions of the invention may be used to treat patients who have been exposed to a particular toxin or pathogen. Accordingly, in one aspect the present invention provides a method of treating an infectious disease in a subject, comprising administering to the subject a bifunctional molecule according to the invention or a pharmaceutical composition comprising the same, preferably such that the infectious disease in the subject is treated.

Any suitable infection may be treated with the bifunctional molecules, nucleic acids, nucleic acid sets, vectors, host cells, or pharmaceutical compositions provided herein.

Some examples of pathogenic viruses that cause infections treatable by the methods of the invention include HIV, hepatitis (type a, type b, or type c), herpes viruses (e.g., VZV, HSV-1, HAV-6, HSV-II, and CMV, EB virus), adenoviruses, influenza viruses, flaviviruses, epox viruses, rhinoviruses, coxsackieviruses, coronaviruses, respiratory syncytial viruses, mumps viruses, rotaviruses, measles viruses, rubella viruses, parvoviruses, vaccinia viruses, HTLV viruses, dengue viruses, papillomaviruses, mollusc viruses, polio viruses, rabies viruses, JC viruses, and arbovirus encephalitis viruses.

Some examples of infectious pathogenic bacteria that can be treated by the methods of the present invention include chlamydia, rickettsia bacteria, mycobacteria, staphylococci, streptococci, pneumococci, meningococci and gonococci (Conococci), klebsiella, proteus, serratia, pseudomonas, legionella, diphtheria, salmonella, bacillus, cholera, tetanus, botulinum, anthrax, plague, leptospirosis and lyme disease bacteria.

Some examples of infectious pathogenic fungi that can be treated by the methods of the present invention include candida (candida albicans, krusei, candida glabrata, candida tropicalis, etc.), cryptococcus neoformans, aspergillus (aspergillus fumigatus, aspergillus niger, etc.), mucor (mucor, trichoderma, rhizopus), trichosporon schel, blastomyces dermatitis, paracoccidioidosporium brazil, pachycoccoides (Coccidioides immitis), and histoplasma.

Some examples of pathogenic parasites that can cause infection treated by the methods of the invention include Entamoeba histolytica, E.coli, neiginea Fuscoporia, echinococcus, giardia lamblia, cryptosporidium, pneumosporon carinii, plasmodium vivax, babesia minuta, trypanosoma brucei, cryptotazium, leishmania donepsis, toxoplasma gondii and Trypanosoma brasiliensis.

Combination therapy

The bifunctional molecules according to the invention may be combined with some other potential strategies for overcoming immune evasion mechanisms in clinical development or already marketed agents (see Table 1, from Antonia et al Immuno-oncology combinations: a review of clinical experience and future proctos. Clin. Cancer Res. Off. J. Am. Assoc. Cancer Res.20,6258-6268,2014). Such a combination with a bifunctional molecule according to the invention is particularly useful for:

1-reverse adaptive immunity inhibition (blocking T cell checkpoint pathways);

2-opening adaptive immunity (using agonist molecules, in particular antibodies, promoting T cell costimulatory receptor signaling),

3-enhancing the function of innate immune cells;

4-activate the immune system (enhance immune cell effector function), for example by a vaccine-based strategy.

Thus, also provided herein is a combination therapy of any bifunctional molecule or a pharmaceutical composition comprising a bifunctional molecule as described herein with a suitable second agent for the treatment of a disease or disorder. In one aspect, the bifunctional molecule and the second agent may be present in a unique pharmaceutical composition as described above. Alternatively, the term "combination therapy" or "combined therapy" as used herein includes administration of the two agents (e.g., a bifunctional molecule as described herein and an additional or second suitable therapeutic agent) in a sequential manner, i.e., wherein each therapeutic agent is administered at a different time, as well as administration of the therapeutic agents or at least two agents in a substantially simultaneous manner. Sequential or substantially simultaneous administration of each agent may be achieved by any suitable route. These agents may be administered by the same route or by different routes. For example, a first agent (e.g., a bifunctional molecule) may be administered orally, and an additional therapeutic agent (e.g., an anticancer agent, an anti-infective agent, or an immunomodulator) may be administered intravenously. Alternatively, the agents of the selected combination may be administered by intravenous injection, while the other agents of the combination may be administered orally.

In one aspect, the additional therapeutic agent may be selected from a non-exhaustive list comprising alkylating agents, angiogenesis inhibitors, antibodies, antimetabolites, antimitotics, antiproliferatives, antivirals, aurora kinase inhibitors, apoptosis promoters (e.g., bcl-2 family inhibitors), death receptor pathway activators, bcr-Abl kinase inhibitors, biTE (bispecific T cell engager) antibodies, antibody drug conjugates, biological response modifiers, bruton's Tyrosine Kinase (BTK) inhibitors, cyclin-dependent kinase inhibitors, cell cycle inhibitors, cyclooxygenase-2 inhibitors, leukemia virus oncogene homolog (ErbB 2) receptor inhibitors, growth factor inhibitors, heat Shock Protein (HSP) -90 inhibitors, histone Deacetylase (HDAC) inhibitors, hormonal therapies, immune formulations, inhibitors of Apoptotic Protein (IAP) inhibitors, intercalating antibiotics, kinase inhibitors, kinesin inhibitors, jak2 inhibitors, mammalian rapamycin target inhibitors, micrornas, mitogen-activated extracellular signal-regulating kinase inhibitors, multivalent binding proteins, nonsteroidal anti-inflammatory drugs (NSAIDs), poly ADP (biphosphate) -ribose polymerase (PARP) inhibitors, platinum chemotherapeutics, polo-like kinase (Plk) inhibitors, phospho 3 kinase (PI 3K) inhibitors, proteasome inhibitors, purine analogs, pyrimidine analogs, tyrosine kinase inhibitors, vitamin a, small nucleic acid inhibitors, siRNA (siRNA) and the like, topoisomerase inhibitors, ubiquitin ligase inhibitors, hypomethylators, checkpoint inhibitors, peptide vaccines and the like, epitopes or neoepitopes from tumor antigens, and combinations of one or more of these agents.

For example, the additional therapeutic agent may be selected from chemotherapy, radiation therapy, targeted therapy, anti-angiogenic agents, hypomethylating agents, cancer vaccines, epitopes or neoepitopes from tumor antigens, bone marrow checkpoint inhibitors, other immunotherapies, and HDAC inhibitors.

In one embodiment, the invention relates to a combination therapy as defined above, wherein the second therapeutic agent is in particular selected from therapeutic vaccines, immune checkpoint blockers or activators, in particular adaptive immune cells (T and B lymphocytes) and antibody-drug conjugates. Preferably, suitable agents for use with any bifunctional molecule according to the invention or with a pharmaceutical composition include antibodies that bind to a co-stimulatory receptor (e.g., OX40, CD40, ICOS, CD27, HVEM or GITR), agents that induce immunogenic cell death (e.g., chemotherapeutic agents, radiotherapeutic agents, anti-angiogenic agents or agents for targeted therapy), agents that inhibit checkpoint molecules (e.g., CTLA4, LAG3, TIM3, B7H4, BTLA or TIGIT), cancer vaccines, agents that modify immunosuppressive enzymes (e.g., IDO1 or iNOS), agents that target Treg cells, agents that adoptive cell therapy, or agents that modulate bone marrow cells.

In one embodiment, the invention relates to a combination therapy as defined above, wherein the second therapeutic agent is an immune checkpoint blocker or an adaptive immune cell (T and B lymphocyte) activator selected from the group consisting of anti-CTLA 4, anti-CD 2, anti-CD 28, anti-CD 40, anti-HVEM, anti-BTLA, anti-CD 160, anti-TIGIT, anti-TIM-1/3, anti-LAG-3, anti-2B 4 and anti-OX 40, anti-CD 40 agonist, CD40-L, TLR agonist, anti-ICOS, ICOS-L and B cell receptor agonist.

The invention also relates to a method for treating a disease in a subject comprising administering to the subject a therapeutically effective amount of a bifunctional molecule or a pharmaceutical composition as described herein and a therapeutically effective amount of an additional or second therapeutic agent.

Specific examples of additional or second therapeutic agents are provided in WO 2018/053106, pages 36-43.

In a preferred embodiment, the second therapeutic agent is selected from the group consisting of a chemotherapeutic agent, a radiotherapeutic agent, an immunotherapeutic agent, a cell therapeutic agent (e.g., CAR-T cells), an antibiotic, and a probiotic.

Combination therapy may also rely on the administration of bifunctional molecules in combination with surgery.

In particular, the bifunctional molecules according to the invention are used in combination with a second bifunctional molecule comprising at least one antigen binding domain that binds to a target specifically expressed on the surface of an immune cell and at least one immunostimulatory cytokine.

More specifically, in such a second bifunctional molecule, the immunostimulatory cytokine is selected from the group consisting of IL2, IL-4, IL-5, IL-6, IL-12A, IL-12B, IL-13; IL-15, IL-18, IL-21, IL-23, IL-24; ifnα, ifnβ, BAFF, ltα and ltβ or variants thereof. In a preferred embodiment, the immunostimulatory cytokine is IL2 or a variant thereof.

More specifically, in such a second bifunctional molecule, the target specifically expressed on the surface of the immune cell is selected from the group consisting of PD-1, CD28, CTLA-4, BTLA, TIGIT, CD160, CD40L, ICOS, CD, OX40, 4-1BB, GITR, HVEM, tim-1, LFA-1, TIM3, CD39, CD30, NKG2D, LAG3, B7-1, 2B4, DR3, CD101, CD44, SIRPG, CD28H, CD38, CD3, PDL2 and PDL1.

Preferably, the bifunctional molecule according to the invention comprising a single antigen binding domain directed against PD-1 and a single IL-7 variant is used in combination with a bifunctional molecule comprising i) an antigen binding domain directed against PD-1 and ii) IL-2 or an IL-2 mutant.

The bifunctional molecule of the invention and the second bifunctional molecule are administered simultaneously or sequentially. In the example of sequential administration, the bifunctional molecule of the invention is administered prior to the administration of the second bifunctional molecule. In another example, the bifunctional molecule of the invention is administered after the administration of the second bifunctional molecule.

In a preferred embodiment, the invention relates to a bifunctional molecule, nucleic acid, host cell or pharmaceutical composition for use in combination with a second bifunctional molecule comprising at least one antigen binding domain that binds to a target specifically expressed on the surface of an immune cell and at least one IL2, wherein the bifunctional molecule of the invention is administered after administration of the second bifunctional molecule.

Kit for detecting a substance in a sample

Any bifunctional molecule or composition described herein may be included in a kit provided by the present invention. The present disclosure provides, inter alia, kits for enhancing an immune response and/or treating a disease or disorder (e.g., cancer and/or infection).

In the context of the present invention, the term "kit" refers to two or more components (one of which corresponds to a bifunctional molecule, nucleic acid molecule, vector or cell of the present invention) packaged in a container, receptacle or other device. Thus, a kit may be described as a set of products and/or appliances sufficient to achieve a particular goal, which may be sold as a single unit. The kit of the invention is suitably packaged.

In particular, the kit according to the invention may comprise:

A bifunctional molecule as defined above,

a nucleic acid molecule or a group of nucleic acid molecules encoding said bifunctional molecule,

-a vector comprising said nucleic acid molecule or group of nucleic acid molecules, and/or

-a cell comprising said vector or nucleic acid molecule or group of nucleic acid molecules.

Thus, the kit may comprise the pharmaceutical composition, fusion protein or bifunctional molecule of the invention, and/or host cell, and/or vector encoding the nucleic acid molecule of the invention, and/or the nucleic acid molecule of the invention or a related agent in a suitable container means. In some examples, a device for obtaining a sample from an individual and/or assaying a sample may be provided. The compositions comprised in the kit according to the invention may in particular be formulated as syringe-compatible compositions.

In some embodiments, the kit further comprises additional reagents for treating cancer or infectious disease, and the additional reagents may be combined with the pharmaceutical compositions, fusion proteins or bifunctional molecules of the invention, and/or host cells, and/or vectors encoding the nucleic acid molecules of the invention, and/or nucleic acid molecules, or other components of the kit of the invention, or may be provided separately in the kit. In particular, the kits described herein may include one or more additional therapeutic agents, such as those described in the "combination therapies" described above. The kit may be tailored for a specific cancer of an individual and comprise a corresponding second cancer therapy for the individual as described above.

Instructions associated with the use of the bifunctional molecules or pharmaceutical compositions described herein generally include information regarding dosages, dosing regimens, routes of administration for the intended treatment, methods for reconstituting the bifunctional molecules of the invention, and/or methods for diluting the bifunctional molecules of the invention. The instructions provided in the kits of the invention are typically written instructions on a label or packaging instructions (e.g., paper sheets contained in the kit in the form of a leaflet or instructions).

Examples

Example 1. Anti-PD-1 IL-7 molecules with one IL-7W142H cytokine and one or 2 anti-PD-1 arms demonstrate the high potency of promoting cis-activity into PD-1+IL-7R+ cells and stimulating proliferation of IL-7R T cells in vivo and the synergistic ability to re-activate TCR signaling.

The inventors designed and compared the biological activities of various structures of bifunctional molecules comprising one or two anti-PD-1 binding domains and one or two IL 7W142H mutants, as shown in figure 1.

Construct 1 comprises two anti-PD-1 antigen binding domains and two IL-7W142H variants (construct 1 is also referred to as anti-PD-1 x 2IL-7W142H x 2). This molecule is also known as BICKI-IL-7W142H. In the examples, the control molecule, designated BICKI-IL-7WT, corresponds to construct 1, but has wild-type IL-7.

Construct 2 contained two anti-PD-1 antigen binding domains and a single IL-7W142H variant (construct 2 was also referred to as anti-PD-1 x 2IL-7W142H x 1).

Construct 3 contained a single anti-PD-1 antigen binding domain and a single IL-7W142H variant (construct 3 is also referred to as anti-PD-1 x 1IL-7W142H x 1). The control structure, designated anti-PD-1*1, was similar to construct 3 but without the IL-7 variant.

Construct 4 comprises a single anti-PD-1 antigen binding domain and two IL-7W142H variants (construct 4 is also referred to as anti-PD-1 x 1IL-W142H x 2).

Constructs 2, 3 and 4 were engineered with the IgG 1N 298A isotype and the amino acid sequence was mutated in the Fc portion to create a pestle on CH2 and CH3 of heavy chain a and a mortar on CH2 and CH3 of heavy chain B.

ELISA assays demonstrated that all anti-PD-1 IL7 constructs had high affinity for the PD-1 receptor (FIG. 2A and Table 1). anti-PD-1 IL-7 molecules with 2 anti-PD-1 arms (anti-PD-1*2) have the same binding efficacy (equal to EC 50) compared to anti-PD-1*2 without IL-7. Similarly, anti-PD-1 IL-7 molecules with 1 anti-PD-1 arm (anti-PD-1 x 1IL 7w142h x 1 and anti-PD-1 x 1IL 7w142h x 2) exhibited the same binding efficacy compared to anti-PD-1*1 without IL-7, with EC50 for anti-PD-1 IL7 equal to 0.086 and 0.111nM and EC50 for anti-PD-1 equal to 0.238nM. These data indicate that fusion of IL-7 does not interfere with PD-1 binding, regardless of the construct tested.

Table 1. ED50 determination in FIG. 2A refers to the concentration required to achieve 50% PD1 binding signal for each anti-PD-1 IL-7 molecule measured by ELISA.

In addition, PD-L1/PD-1 antagonist bioassays (FIG. 2B) indicate that anti-PD-1 IL7 molecules with 1 or 2 anti-PD-1 arms have been shown to block the binding of PD-L1 to the PD-1 receptor with high efficacy. Although one arm of anti-PD-1 was removed from constructs 3 and 4, all anti-PD-1 x 1il7 constructs exhibited high antagonistic properties. The activity was only reduced by a factor of 2.5 compared to the anti-PD-1 x 2il7 construct, calculated according to EC50 of constructs 3 and 4 (table 2).

Table 2. ED50 determination in FIG. 2B refers to the concentration required to achieve 50% PD1/PDL1 antagonist activity measured by ELISA for each anti-PD-1 IL-7 molecule.

The inventors next evaluated the affinity of the different constructs for CD127 receptor using Biacore assay and ELISA assay. Because one IL-7 molecule was removed from constructs 2 and 3, these molecules were expected to have lower binding capacity to the CD127 receptor and lower pSTAT5 activation compared to the IL-7 heterodimer construct. However, the inventors observed that the anti-PD-1 x 2IL-7W142H 1 molecule had similar affinity for CD127 receptor compared to anti-PD-1 x 2IL-7W142H (BICKI-IL-7W 142H) and, as expected, lower affinity compared to anti-PD-1 IL7 bifunctional molecules comprising the wild-type form of IL-7 (table 3). Surprisingly, the anti-PD-1 x 2IL 7w142h 1 and anti-PD-1 x 1IL 7w142h 1 molecules exhibited high pSTAT5 activity similar to the PD-1IL7 bifunctional molecules comprising the wild-type form of IL-7 (figure 3). Based on these observations, the combination of the monomeric form of IL-7 with the W142H IL-7 mutation appears to allow the optimal conformation of the IL-7 molecule to promote IL-7 signaling into human T cells. Even with only one IL7, the molecule with the W142HIL-7 mutation had as good an activation effect (pSTAT 5) as the IL7wt molecule with two cytokines. This result is surprising in the case of IL-7 variants having a lower affinity for their receptor than wild-type IL-7.

A similar conclusion was drawn with anti-PD-1 IL7 molecules constructed with one anti-PD-1 arm fused to one IL-7W142H mutant. Similar and comparable high pSTAT5 activity was obtained with anti-PD-1 x 2il-7wt x 2, anti-PD-1 x 2il-7w142h x 1 and anti-PD-1 x 1il-7w142h x 1 constructs (fig. 3C)

TABLE 3 binding of anti-PD 1IL7 wild-type or anti-PD 1IL7W142H mutants constructed with 1 or 2IL 7. CD127 was immobilized onto a sensor chip and anti-PD-1 IL-7 bifunctional molecules were added in increasing doses to measure affinity.

In vivo experiments were performed to determine the efficacy of the different anti-PD-1 IL-7 constructs. A dose of anti-PD-1 IL-7 molecules was injected into mice at equimolar concentration (34 nM/kg). On day 4 post-treatment, CD4 and CD 8T cell proliferation was quantified by flow cytometry using Ki67 markers. Fig. 4 shows that anti-PD-1 IL7 molecules with single W142H mutants (anti-PD-1 x 2IL-7W142H x 1 and anti-PD-1 x 1IL-7W142H x 1) or with single PD-1 valency and two IL7W142H cytokines (anti-PD-1 x 1IL7W142H x 2) show high efficiency in promoting CD8 and to a lesser extent CD 4T cell proliferation.

To determine the ability of a bifunctional molecule comprising an anti-PD 1 antibody (monovalent or bivalent) and one or two IL7 mutant cytokines to reactivate TCR-mediated signaling, an NFAT bioassay was performed. FIG. 5A shows that the bifunctional molecule constructed with 2 anti-PD-1 arms and one IL-7 cytokine enhances NFAT activation compared to anti-PD-1 antibody alone, indicating that the synergistic activity of the drug in enhancing TCR-mediated signaling is conserved with anti-PD-1 IL-7 bifunctional molecules constructed with only one IL-7 cytokine. As shown in fig. 9A, this synergy was absent when cells were treated with a combination of anti-PD 1 plus IL 7.

Furthermore, the inventors next assessed the activity of anti-PD-1 IL-7 molecules designed with only one anti-PD-1 valency (anti-PD-1*1) and demonstrated that the anti-PD-1 x 1IL-7W142H construct (anti-PD-1 x 1IL7W142H 1 and x 2) retained their synergistic activity, whereas combination treatment with the PD-1*1+ isoform IL-7W142H x 2 showed lower efficacy in stimulating TCR signaling (NFAT activation). (FIG. 5B).

Finally, specific cis-targeting and cis-activity of the different anti-PD-1 IL-7 constructs were analyzed in a co-culture assay. U937 PD-1+cd127+ cells were mixed with PD-1-cd127+ cells (ratio 1:1) and then incubated with different constructs at increasing doses. Binding and IL-7R signaling (pSTAT 5) were quantified by flow cytometry. Binding EC50 (nM) and pSTAT5 activation were determined for each construct and for each PD-1+ and PD-1-cell population (fig. 6A and B). The inventors have verified that a number of anti-PD-1 IL-7 mutant molecules (anti-PD-1 x 2IL 7w142h x 1, anti-PD-1 x 1IL7w142h x 2) substantially preferentially bind IL-7R to PD-1+ cells while substantially activating IL7R signal pSTAT5 into PD-1+ cells. Importantly, constructs PD-1 x 1il7w142h 1 showed the highest activity in stimulating pSTAT5 signaling to PD-1+ cells compared to the other constructs (anti-PD-1 x 2il 7w142h 1 and anti-PD-1 x 1il7w142h 2). These data indicate that bifunctional molecules constructed from one anti-PD-1 arm and one IL-7 have optimal conformation and activity, allowing preferential activation of IL-7R into PD-1+ activated T cells in the context of cancer.

Example 2: anti-PD-1 IL-7 molecules constructed with 1 or 2 anti-PD-1 arms and 1 or 2IL7W 142H cytokines have good pharmacokinetic profiles in vivo

Pharmacokinetic studies of anti-PD-1 IL-7 bifunctional molecule constructs 2, 3 and 4 as described in figure 1 were evaluated. Humanized PD1 KI mice were intraperitoneally injected with a dose of anti-PD-1 IL-7 molecule (34.4 nM/kg). Plasma drug concentrations were analyzed by human IgG-specific ELISA (fig. 7). The area under the curve (see table 4) was also calculated and represents the total drug exposure of each construct over time. The anti-PD-1 x 2il-7w142h 1, anti-PD-1 x 1il-7w142h 1 and anti-PD-1 x 1il-7w142h 2 constructs exhibited very advantageous enhanced PK properties compared to anti-PD-1 x 2il7wt 1. Cmax was observed to be 2.8 to 19 fold higher compared to anti-PD-1 x 1i l7wt x 2. Importantly, anti-PD-1 x 1il7w142h 1 anti-PD-1 x 1i 7w142h 2 molecules maintained high drug concentrations (11-15 nM) corresponding to satisfactory in vivo PK values for at least 96 hours, whereas only 2nM of anti-PD-1 x 2i 7wt 2 molecules were detected in plasma. The residual drug concentration of anti-PD-1 x 2il-7w142h x 1 was 2.5 fold higher than the anti-PD-1 x 2il7wt x 2 concentration. Plasma drug exposure is often associated with in vivo efficacy. Here, the inventors demonstrate that all anti-PD-1 IL-7W142H molecules constructed with one arm against PD-1 allow for long term drug exposure after a single injection. While anti-PD-1 x 2il-7w142h x 1, anti-PD-1 x 1il-7w142h x 1 and anti-PD-1 x 1il-7w142h x 2 exhibited similar favorable PK properties in vivo, figure 6B demonstrates that the anti-PD-1 x 1il-7w142h x 1 construct has a higher capacity to activate PD-1+ cells.

	AUC	Cmax(nM)
			anti-PD 1 x 1il7w142h x 1	1597	42.4
anti-PD-1 x 1il7w142h x 2	2024	248.6

Table 4. Area under the curve of fig. 7 was measured. AUC was calculated 0 to 96 hours after intraperitoneal injection of one dose of anti-PD-1 IL-7 (34 nM/kg).

Example 3. Bifunctional antibodies constructed with one anti-PD-1 valency and one fusion protein X exhibit higher productivity in mammalian cells compared to bifunctional antibodies constructed with two anti-PD-1 valencies and one fusion protein X.

The productivity of form B and form C of the bifunctional antibodies of mammalian cells was evaluated and compared. Full heavy and light chains with Fc fused to IL-7 were transiently co-transfected into CHO suspension cells. The amount of antibody produced and obtained after purification was quantified using a sandwich ELISA (immobilized donkey anti-human Fc antibody for detection and disclosure, goat anti-mouse antibody conjugated with mouse anti-human kappa+ peroxidase). The concentration was determined using human IvIgG standards. Productivity was calculated as the amount of purified antibody per liter of culture supernatant collected.

Results: bifunctional antibodies, anti-PD-1*2/IL-7*1 (form B) and antibodies PD-1 x 1IL-7*1 (form C) were produced in CHO mammals and the results are shown in FIG. 8. Surprisingly, the anti-PD-1*1/IL-7*1 construct (form C) has significantly better yields (mg/L) than the anti-PD-1*2/IL-7*1 (form B). Productivity was significantly improved by 1.7-fold (+/-0.7; n=5). These results indicate that anti-PD-1*1/IL-7*1 (form C) has very good manufacturability, which is important for the next clinical development and therapeutic application.

In particular, for bifunctional antibodies comprising two different arms, one major problem is the mismatch of the chains and the false association of chain a (knob chain) with chain B (mortar chain). In fact, undesired homodimeric formation (chain a+chain a or chain b+chain B) generally occurs. This generally results in lower yields and purities of heterodimeric bifunctional antibodies (forms B and C) than production of homodimeric bifunctional antibodies (form a), which is a significant disadvantage. One key challenge remains in how to produce homogeneous bifunctional antibodies of high quality with limited or negligible by-products and impurities.

However, the inventors demonstrate that by using the optimization strategy design of form C, surprisingly higher yields of bifunctional antibodies are induced compared to homodimeric form B. In addition, the yield of anti-PD-1*1-IL-7*1 was in a similar range as anti-PD-1 alone (anti-PD-1*1 or anti-PD-1*2), and under similar production conditions, the yield was equal to 45mg/L (n=5).

Another major problem with heterodimeric antibody production is purity. Although the pestle-in-mortar strategy favors heterodimer production (chain a+chain B) and reduces homodimer chain a or homodimer chain B production, this strategy is not 100% efficient, requiring additional purification to isolate the heterodimer construct (Wang et al, 2019, antibodies,8, 43).

However, the inventors observed that after the production of anti-PD-1*1/IL-7*1 form C, a high yield of heterodimer was obtained. FIG. 9 shows size exclusion chromatography of anti-PD-1*1/IL-7wt.1 (FIG. 9A) and anti-PD-1*1/IL-7v.1 (FIG. 9B) after protein A purification. Corresponding to one major peak of heterodimeric forms chain a and chain B, homodimeric form Fc/Fc (chain a+chain a) was not detected, and homodimeric form (chain a+chain a) was very small (less than 2%). These data indicate that the anti-PD-1*1/IL-7*1 of the invention is optimized for productivity and prevents mismatches. In contrast to the prior art, heterodimer yields of about 70 to 75% of heterodimers were obtained with other bispecific antibody backbones using the same KIHs-s strategy.

To obtain such purity, the inventors have optimized the design of the molecule. In fact, they observed that this high purity could be obtained only when the a chain is the Fc domain and the B chain is anti-PD-1 x 1 il-7*1. Co-transfection of VL+ single chain B (anti-PD-1*1/IL-7 v 1) containing the mortar mutation into CHO mammalian cells did not induce B chain homodimer (0 mg/L) production. In contrast, if anti-PD-1*1/IL-7 v 1 is the A chain comprising the pestle mutation, high yields of homodimeric A chain (88 mg/L) can be obtained after co-transfection of VL+single chain A (anti-PD-1*1/IL-7 v 1). Based on these data, the inventors chose to design molecules with Fc as the A chain and anti-PD-1*1/IL-7*1 as the B chain to avoid the production of A chain homodimers.

Taken together, these data indicate that form C with chain a (Fc domain with a knob mutation) and chain B (anti-PD-1*1/IL-7 with a knob mutation) according to the invention is the best construct for high productivity and purity of the product. This facilitates development as a therapeutic agent to achieve mass production.

Example 4: anti-PD-1/cytokine bifunctional antibodies activate pSTAT5 signaling in primary human T cells

The inventors next assessed the biological activity of the proteins fused to anti-PD-1 antibodies and tested the ability of all anti-PD-1/cytokine bifunctional molecules to activate primary T cells. For this, human peripheral blood T cells were treated with different concentrations of anti-PD-1*1/IL-7wt 1, anti-PD-1*1/IL-7v 1, anti-PD-1*1/IL-15 x 1, anti-PD-1*1/IL-21 x 1 constructs for 15 min at 37 ℃. After incubation, cells were fixed, permeabilized and stained with anti-pSTAT 5 antibody.

Results:FIG. 10A shows that anti-PD-1*1/IL-7 wt 1, anti-PD-1*1/IL-7 v 1, anti-PD-1*1/IL-15 x 1 and anti-PD-1*1/IL-21 x 1 are effective in inducing the transfer of pSTAT5 signals into primary T cells (CD3+ T cells), indicating that cytokines fused to the Fc domain of the anti-PD-1 molecule of form C retain their ability to stimulate human T cells. Next, the inventors compared the efficacy of anti-PD-1/IL-7 form a (anti-PD-1*2/IL 7v x 2) to activate pSTAT5 signaling against PD-1*1/IL-7v x 1 form C. Since the anti-PD-1*1/IL-7 v 1 construct contained only one IL-7v cytokine, the molecules were expected to have lower pSTAT5 activation compared to form a. However, as shown in fig. 10B, a higher pSTAT5 activation against PD-1*1/IL-7v x 1 (form C) was surprisingly observed compared to the anti-PD-1*2/IL-7 v x 2 construct (form a), indicating that the anti-PD-1/IL-7*1 construct (form C) of the invention allows for an optimal conformation of the IL-7 molecule to promote activation of IL-7 signaling in primary T cells.

Example 5: anti-PD-1 bifunctional molecules allow preferential binding to PD-1+ over PD-1-cells, and anti-PD-1/IL 7 molecules allow synergistic activation of TCR signaling into PD-1+ t cells.

The inventors evaluated the ability of anti-PD-1 bifunctional molecules to target PD-1+ t cells and allow preferential delivery and cis-binding of cytokines or proteins fused to PD-1+ cells. U937 PD-1-cells and U937 PD1+CD127 +cells were co-cultured (ratio 1:1) and incubated with anti-PD 1/IL-7 molecules at increasing doses. Binding and IL-7R signaling (pSTAT 5) were quantified by flow cytometry. EC50 (nM) and pSTAT5 activation were determined for each construct and binding of each PD-1+ and PD-1-cell population. Meanwhile, the binding of the bifunctional antibody was detected with anti-IgG-PE (Biolegend, clone HP 6017) and analyzed by flow cytometry.

Results: FIGS. 11A and 11B show the binding of anti-PD-1*1/IL-7wt 1 and anti-PD-1*1/IL 7v 1 molecules on cells expressing CD127+ alone or coexpression of CD127 and PD-1 receptors. The data show that these two molecules preferentially bind to PD-1+cd127+ cells compared to PD-1-cd127+ cells, with efficacy comparable to anti-PD-1 (anti-PD-1*2) alone. At the same time, activation of PSTAT5 signaling into PD-1+ cells was also assessed relative to PD-1-cells, as shown in fig. 11C. IL7R signaling pSTAT5 was strongly activated (58 to 315 fold more activation) in PD-1+CD127+ cells compared to PD-1-CD127+ cells following treatment with anti-PD-1*1/IL-7wt or IL7v 1 antibodies, whereas isotype/IL 7 antibodies have similar efficacy in PD-1+ and PD-1-cells confirming that the anti-PD-1 domain of the anti-PD-1*1/IL-7*1 molecule allows preferential binding of IL-7 to PD-1+ cells, i.e., drug targeting and activation on the same cell. This aspect is of interest for in vivo biological activity of the drug because anti-PD-1 IL-7 will aggregate IL-7 or other molecules fused in bifunctional molecules onto PD-1+ tumor specific T cells in the tumor microenvironment, rather than PD-1 negative naive T cells. Taken together, the data indicate that only one arm against PD-1 is sufficient to allow selective delivery of fused cytokines on PD-1+ cells.

Next, the inventors evaluated the biological impact of cis-targeting of anti-PD-1 bifunctional molecules on PD-1+t cells. Measured using Promega PD-1/PD-L1 kit (reference number J1250). Briefly, two cell lines were used: (1) Effector T cells (Jurkat stably expressing PD-1, NFAT-induced luciferase) and (2) activated target cells (CHO K1 cells stably expressing PD-L1 and surface proteins, intended to stimulate homologous TCRs in an antigen-independent manner). When cells are co-cultured, the PD-L1/PD-1 interaction inhibits TCR-mediated activation, thereby blocking NFAT activation and luciferase activity. The addition of anti-PD-1 antibodies blocks PD-1 mediated inhibition signals and restores TCR-mediated signaling, resulting in NFAT activation and luciferase synthesis and emission of bioluminescent signals.

The bioassay results are shown in fig. 12A, which shows that the bifunctional anti-PD-1*1/IL 7wt 1 molecule activated TCR-mediated signaling (NFAT) better than anti-PD 1 x 1 or anti-PD 1 x 1+ non-targeting isoform-IL 7 (as a separate compound), demonstrating the synergistic effect of the bifunctional molecule on pd1+ T cells. anti-PD-1*1/IL-7v 1 molecules comprising IL-7 mutants also showed a significant synergistic effect to re-activate NFAT signaling on T cells (fig. 12B). These data indicate that fusion of one IL-7 cytokine with one anti-PD-1*1 advantageously induces higher activation of TCR signaling, whereas the combined strategy of the two individual compounds does not induce this effect.

Example 6. Bifunctional molecules with one anti-PD-1 valency exhibit better in vivo pharmacokinetics.

The pharmacokinetics and pharmacodynamics of the product were evaluated in mice after a single injection. C57bl6JRj mice (6-9 week females) were injected intravenously or intraperitoneally with single doses (34 nmol/kg) of anti-PD-1 or bifunctional antibodies. Plasma drug concentrations were determined by ELISA using immobilized anti-human light chain antibody (clone NaM76-5F 3) followed by the addition of serum-containing antibodies. Detection was performed using peroxidase-labeled donkey anti-human IgG (Jackson Immunoresearch; USA; reference 709-035-149) and revealed by conventional methods. The area under the curve for each construct corresponding to drug exposure was calculated.

Results: the inventors first compared the pharmacokinetics of all the different bifunctional forms (forms A, B and C). FIG. 13 shows the pharmacokinetic profile of anti-PD-1/IL-7 v constructed with 1 or 2 IL-7v cytokines and 1 or 2 anti-PD-1 valencies after a single intravenous (FIG. 13A) or intraperitoneal (FIG. 13B) injection. Compared to anti-PD-1*2/IL-7 v x 2 (form a) and anti-PD-1*2/IL-7 v x 1 (form B), anti-PD-1*1/IL-7 v x 1 (form C) exhibited the best pharmacokinetic profile. Both intravenous and intraperitoneal injection demonstrated that anti-PD-1*1/IL-7*1 (form C) is the best construct to enhance the pharmacokinetics of bifunctional molecules.

Next, the inventors tested whether bifunctional molecules with 1 anti-PD-1 arm (anti-PD-1*1) and IL-7 exhibited better pharmacokinetic profile in vivo than the same bifunctional molecules with 2 anti-PD-1 arm constructs. FIG. 14 shows the results of the individual constructs. The data show that all anti-PD-1*1/IL-7 bifunctional molecules (form C) exhibit significantly better pharmacokinetic profiles than the corresponding anti-PD-1*2/IL-7*1 bifunctional molecule (form B).

In another experiment, the pharmacokinetics of anti-PD-1*2 or anti-PD-1*1 antibodies alone were also evaluated to see if the anti-PD-1 construct alone could provide better pharmacokinetic profiles or if this observation only applies to bifunctional molecules. Fig. 15 shows that anti-PD-1*2 and anti-PD-1*1 have similar curves after intravenous (fig. 15A) or intraperitoneal (fig. 15B) injection, indicating that, surprisingly, the anti-PD-1*1 construct induces better pharmacokinetic curves for bifunctional molecules only.

Poor pharmacokinetic profiles are a well-known challenge faced by bifunctional antibodies. The bifunctional antibody is rapidly eliminated, has a short half-life in vivo, and limits its clinical use. With the anti-PD-1*1/IL-7*1 construct, good drug concentrations (20 and 100 nM) corresponding to satisfactory in vivo PK values can be maintained for at least 48-72 hours, whereas only 2nM of anti-PD-1 x 2i l7 x 2 molecules are detected in plasma. The form C anti-PD-1*1/IL-7*1 of the invention allows for improved in vivo pharmacokinetic profile with longer exposure compared to other forms of bifunctional antibodies (forms B and C).

Example 7 anti-PD-1/IL-7*1 bifunctional molecules promoted proliferation of T cells in vivo and induced significant anti-tumor efficacy compared to anti-PD-1*2/IL 7*2 or anti-PD-1*2/IL 7*1 constructs.

Following intraperitoneal injection of a single dose of bifunctional molecule (34 nM/kg) into subcutaneous MC38 tumors, T cell proliferation was assessed in vivo. On day 4 post-treatment, blood and tumors were collected and T cells were stained with anti-Ki 67 antibody for quantitative proliferation by flow cytometry.

In vivo efficacy was evaluated in two different in situ isogenic models (liver cancer model and mesothelioma in situ model). These experiments used immunocompetent mice genetically modified to express human PD-1 (exon 2). For mesothelioma model, AK7 mesothelial cells were intraperitoneally injected (3 x 10 ⁶ Cell/mouse). For the Hepa 1.6 model, 2.5×10 was injected in portal vein ⁶ Individual cells. In experiment 1, mice received PBS, anti-PD-1 control (anti-PD-1*2), anti-PD-1*1/IL 7v 1 treatment at similar drug exposure concentrations. In experiment 2, mice received PBS, anti-PD-1 control (anti-PD-1*2), anti-PD-1*1/IL 7wt 1 treatment at similar drug exposure concentrations. AK7 cells stably expressed luciferase allowing in vivo quantification of tumor burden after D-luciferin injection. The data were analyzed in photons per second per square centimeter per steradian and represent the average of the dorsal and ventral signals.

Results: fig. 16A shows that anti-PD-1*1/IL 7wt 1 or IL7v 1 bifunctional molecules (form C) promote significant proliferation of CD4 and CD8T cells to a higher extent than anti-PD-1 antibodies (anti-PD-1*1 or anti-PD-1*2). Significantly superior CD 4T cells were also observed for these 2 constructs compared to the anti-PD-1*2/IL 7 x 2 (form a) and anti-PD-1*2/IL 7 x 1 (form B) constructs. Also, higher proliferation was observed following treatment with anti-PD-1*1/IL 7wt 1 or anti-PD-1*1/IL-7 v 1 compared to anti-PD-1*2/IL 7 x 2 (form a) and anti-PD-1*2/IL 7 x 1 (form B) constructs. These data demonstrate the efficiency of the different constructs to activate pSTAT5 signaling into T cells (fig. 10A), with the anti-PD-1*1/IL 7 x 1 construct inducing higher pSTAT5 signaling than the anti-PD-1*2/IL 7 x 2 construct.

Interestingly, the inventors observed that anti-PD-1*1/IL 7wt 1 or IL7v 1 significantly induced proliferation of stem cell-like effector memory CD8T cells into tumors to a significantly higher extent than anti-PD-1 x 2IL-7*2 and anti-PD-1*2 molecules (fig. 16B). The ability of anti-PD-1 x 1il-7*1 to enhance tcf1+ stem cell-like CD8T cell populations is of particular interest, as this is critical for immune control of cancer. These cells are capable of self-renewal, producing tumor-specific T cell banks with high effector functions.

Figures 17A and 17B show in vivo efficacy of anti-PD-1 x 1il-7wt 1 and anti-PD-1 x 1il-7v 1 in an in situ liver cancer model. In two separate experiments, anti-PD-1*1/IL 7*1 (wild-type and variant) (form C) showed significantly superior efficacy compared to anti-PD-1*2 antibodies. After treatment with anti-PD-1*1/IL 7v, 85% of tumors were completely eradicated (complete remission), whereas only 16% of mice treated with anti-PD-1*2 showed complete tumor remission.

In contrast, the inventors also tested the anti-PD-1*2/IL 7v 2 construct, and observed lower anti-tumor efficacy of the anti-PD-1*2/IL-7*2 construct in the same liver cancer model, indicating superior in vivo activity of the anti-PD-1*1/IL 7 x 1 construct relative to the anti-PD-1*2/IL-7*2.

In mesothelioma in situ model (fig. 18A and B), anti-PD-1*1/IL 7v 1 showed high anti-tumor efficacy, similar to anti-PD-1*2 antibody treatment, complete remission >85%. These data indicate that anti-PD-1*1/IL 7v 1 is very effective in the anti-PD-1 sensitive model, indicating that even if form C contains only one anti-PD-1 arm (anti-PD-1*1), the drug shows similar efficacy as the 2-valent anti-PD-1.

Taken together, these data underscores that the design of bifunctional antibodies is critical to achieving antitumor efficacy in vivo. Fusion of one cytokine or protein with anti-PD-1*1 (form C) showed optimal anti-tumor efficacy and proliferation of T cells in vivo, whereas bifunctional molecules constructed from 2 anti-PD-1 arms and one or 2 cytokines or proteins were unable to induce efficient proliferation of T cells in vivo nor to produce anti-tumor efficacy.

Example 8: the anti-PD-1 x 1IL-7v x 1 construct abrogated the inhibitory function of Treg in vitro to a greater extent than the IL-7 cytokine and anti-PD-1 x 1IL7wt x 1 bifunctional antibody.

Although anti-PD 1 therapies can stimulate T cell effector function, immunosuppressive molecules (TGFB, IDO, IL-10.) and regulatory cells (Treg, MDSC, M macrophages) create an adverse microenvironment that limits the full potential of the therapy. Treg cells express low levels of IL-7R (CD 127), but they are still able to stimulate pSTAT5 after IL-7 treatment, and IL7 is known to release the Treg inhibition function [A, et al j. Immunol 2015,195,31393148; liu W, et al J Exp Med.2006,203,1701-1711; seddiki N, et al J exp Med 2006,203,1693-1700; codarri L, et al j exp Med 2007,204,1533-1541; heninger AK, et al jimmnol 2012,189,5649-5658). To assess the efficacy of anti-PD-1/IL 7 constructs to abrogate Treg function compared to IL-7, inhibition assays were performed by co-culturing Treg and T effector cells. The inventors observed in fig. 19 that IL-7 or anti-PD 1-IL7 treatment blocked Treg-mediated inhibition, allowing Teff cells to proliferate even in the presence of Treg cells. anti-PD 1 antibodies are unable to inhibit the inhibitory activity of tregs on T effector cells.

Surprisingly, anti-PD-1 x 1IL7w 142h x 1 showed the highest efficacy of inhibiting Treg function compared to IL-7 cytokines (< p < 0.05), and also the highest efficacy compared to anti-PD-1 x 1IL7wt x 1 constructs. These data underscores the advantages of using the anti-PD-1 x 1IL7 x 1 construct over the naked IL-7 cytokine or non-mutated version of the anti-PD-1 x 1 bifunctional antibody. Unexpectedly, monovalent variants affect Treg elimination and simultaneously T cell proliferation, which is a dual effect, as the selected IL7 variant W142H has a lower affinity for IL7R compared to the wild-type form of IL-7 cytokine.

The method comprises the following steps: the inhibitory activity of tregs on CD8 effector T cell proliferation was assessed in vitro. Cd8+ effector T cells and autologous cd4+cd25high CD127low tregs were sorted from peripheral blood of healthy donors and stained with cell proliferation dye (CPDe 450 for cd8+ T cells). Treg/cd8+teff was then co-cultured on OKT3 coated plates (2 μg/mL) at a 1:1 ratio for 5 days and proliferation of Teff cells was quantified by flow cytometry by loss of CPD markers.

Example 9: among 2 different tumor models, anti-PD-1 x 1il-7v x 1 showed superior in vivo efficacy compared to the anti-PD-1 x 1il7wt x 1 construct.

In vivo efficacy was evaluated in two different in situ isogenic models (liver cancer model and mesothelioma in situ model). These experiments used genetically modified expression of human PD-1(exon 2) immunocompetent mice. For mesothelioma model, AK7 mesothelial cells were intraperitoneally injected (3 x 10 ⁶ Cell/mouse). For the Hepa1.6 model, 2.5×10 was injected in portal vein ⁶ Individual cells. In experiment 1, mice received PBS, anti-PD-1 control (anti-PD-1*2), anti-PD-1*1/IL 7v 1 (anti-PD-1 x 1i 7w142h 1) or anti-PD-1 x 1i 7wt 1 treatment at similar drug exposure concentrations. AK7 cells and hepa1.6 stably expressed luciferase, allowing in vivo quantification of tumor burden after D-luciferin injection. The data were analyzed in photons per second per square centimeter per steradian and represent the average of dorsal and ventral signals.

AK7 intraperitoneal models were highly sensitive to PD-1 antibody treatment, correlated with high cd4+ and cd8+ T cell infiltration in tumor microenvironments observed to express PD-1, leading to good response of anti-PD-1 antibodies, as shown in figure 18. In the same experiment, the efficacy against PD-1 x 1IL7v x 1 was compared with the efficacy of its wild-type IL7 homolog construct (against PD-1 x 1IL7wt x 1). The anti-PD-1 x 1il7v 1 construct induced 92% of complete response (n=1 dead/14 mice) and had superior efficacy compared to the anti-PD-1 x 1i 1 wt 1 construct inducing moderate anti-tumor efficacy (62% of complete response) (figure 20A). Tumor bioluminescence analysis demonstrated that anti-PD-1 x 1IL7v x 1 induced tumor clearance within 11 to 18 days post treatment, whereas in the anti-PD-1 x 1IL7wt x 1 group, tumors shrink after treatment and then eventually recur (data not shown), suggesting that the efficacy of IL-7 wild type constructs may be transient compared to low affinity IL-7 (IL 7W 142H) constructed bifunctional antibodies.

To evaluate the memory response induced by anti-PD-1 x 1il7v x 1 treatment, all cured mice treated with anti-PD-1 x 1il7v x 1 were re-injected with AK7 mesothelioma cells. As shown in fig. 20B, no tumor bioluminescence was detected after tumor re-challenge, whereas high bioluminescence signals were detected at multiple time points in the initially challenged mice. These data indicate that anti-PD-1 x 1il7v x 1 can induce a strong and long-term specific memory anti-tumor response without any new treatment.

Although the affinity of anti-PD-1 x 1IL7v x 1 for IL-7R is lower, this construct showed unexpectedly higher efficiency than the anti-PD-1 x IL-7wt 1 construct and retained its antagonist anti-PD-1 activity in a PD-1 sensitive tumor model, such as an anti-PD-1*2 antibody. These data underscores that anti-PD-1 x 1il7v x 1 is the preferred construct to maintain PD-1 inhibitory receptor blocking activity in vivo. The inventors hypothesize that mutations in IL-7 will balance the affinity of the bifunctional antibodies for PD-1+ tumor-specific T cells with PD-1-cd127+ non-tumor-specific T cells (as depicted in fig. 11C), resulting in better efficacy of the drug in vivo.

To evaluate the efficacy of the anti-PD (L) 1 refractory model to mimic the primary drug resistance of cancer patients, a mouse model of hepatocellular carcinoma hepa1.6 was selected. It is an in situ homology model implemented in immunocompetent mice (expressing human PD-1). This model is of particular interest since tumor T cells are excluded from the described tumors (Gauttier V et al 2020,Clin Invest,130,6109-6123). The efficacy of anti-PD-1 x 1IL7v x 1 with low affinity for IL7R versus anti-PD-1 x 1IL7wt x 1 with high affinity for IL7R was compared side-by-side in the same experiment. In different groups, mice received PBS (control), anti-PD-1*2 or isotype 1i 7 x v 1 (homologous construction of bispecific antibodies against antiviral protein envelopes and used as isotype control for experiments) at the same drug exposure concentrations. anti-PD-1 x 1IL7v 1 achieved 60% complete tumor response, significantly better than anti-PD-1 x 1IL7wt 1 constructed with high affinity wild-type IL7 (only 47% of complete response), as shown in figure 21. In this model, as expected, the anti-PD 1 antibody was not effective. Furthermore, isotype 1IL7v 1 was not effective in this model, indicating that the use of anti-PD-1/IL 7 constructs in combination with anti-PD-1 and IL-7 treatment is a good therapeutic strategy to enhance T cell activation and anti-tumor response in a PD-1 refractory model.

anti-PD-1 x 1il7v x 1 treatment-induced memory responses were also tested in this model, and the same absence of tumors was observed.

Taken together, these data demonstrate the excellent efficacy of an anti-PD-1/IL-7 construct with an anti-PD-1 valency and an IL-7 cytokine mutation (W142H) with lower affinity for its CD127 receptor.

Example 10: the in vivo efficacy of anti-PD-1 x 1il-7v x 1 demonstrated in the anti-PD-1 refractory model was associated with strong transcriptional activity of anti-PD-1 receptor and intratumoral proliferation of stem cell-like memory CD 8T cell subpopulations (tcf1+tox-cells).

Transcriptome analysis was also performed on the whole tumor to better understand the effect of anti-PD-1 x 1il7v x 1 on tumor microenvironment. Using Nanostring techniquePanCancer Immune profiling panel) to detect and quantify gene expression. The data were normalized to the multiple reference genes contained in the group, with the background threshold being the geometric mean of the negative control. Differential Expression (DEG) of the genes was analyzed using the R-package. The unsupervised hierarchical cluster heatmap of DEG from the DESeq2 analysis of fig. 22 shows that the transcriptional expression pattern between anti-PD-1 and anti-PD-1 x 1 w14h x 1 groups is highly similar and significantly different from PBS group, indicating that the anti-PD-1 domain of the anti-PD-1 x 1 v x 1 construct retains its antagonist bioactivity in vivo despite having one anti-PD-1 valency. Protein-protein interaction network function enrichment analysis using anti-PD-1*2 or anti-PD-1 x 1il7w142h x 1 post-treatment up-regulated sting genes compared to PBS conditions, several gene clusters associated with chemotactic immunoreceptor activity, jak-STAT cytokine signaling, and antigen presentation (MHC protein complex binding and TCR signaling) were identified. Among genes differentially expressed between anti-PD-1*2 and anti-PD-1 x 1i 7w142h x 1, the inventors observed significant upregulation of CD8 or CD4T early activation/memory stem cell-like T cell characteristics associated with expression of anti-PD-1 x 1i 7w142h x 1 genes compared to the TCF7, CCR7, SELL, IL7R genes in the anti-PD-1 x 1i 7w142h x 1 group using the GSEA single sample GSEA (ssGSEA) signature algorithm (fig. 22B). In contrast, as expected, up-regulation of depleted CD 8T cell genes (LAG 3, PRF1, CD8A, HAVRC2, GZMB, CD8B1, KLRD1, TNFRSF9, TIGIT, CTSW, CCL4, CD63, IFNG, CXCR6, FASL, CSF 1) was observed in the anti-PD-1 treatment group. The genetic characteristics of depleted T cells and the characteristics of naive/stem cell-like memory T cells were adapted (Andreatta et al, nature comm 2021) that define different T cell subsets in cancer using single cell transcriptome analysis.

CD 8T cell infiltrating lymphocytes were also analyzed ex vivo by flow cytometry to further characterize the population induced by anti-PD-1 x 1il7v x 1 treatment. Although the exclusion of T cells from tumors was initially described in this drug resistance model, tumor Infiltrating Lymphocyte (TIL) composition significantly increased after anti-PD-1 x 1il7w142h x 1 treatment and the product significantly altered T cell subpopulations (fig. 22B and C, 23C). Flow cytometry analysis showed that anti-PD-1 x 1il7w142h x 1 altered the composition of the tumor microenvironment and facilitated accumulation of CD 8T cells instead of CD 4T cells while not affecting Treg (fig. 23A). A high increase in the percentage of cd8+cd44+ activated T cells with a stem cell-like memory T cell phenotype (cd3+cd8+cd44+tcf1+tox-) was observed after treatment (fig. 23B), which also expressed the ki67 proliferation marker (fig. 23C). anti-PD-1 treatment induces accumulation of TOX-TCF1 or TOX+TCF1-associated depletion phenotypes into tumors (Utzschneider et al, immunity 2016,45,415-427; mann et al, 2019Nature immunology,20,1092-1094). These data confirm transcriptome analysis and further confirm that T cells activated against PD-1 x 1il7w142h x 1 molecules express CD44 activation markers, indicating that this T cell subpopulation is not the initial T cell subpopulation, but an early activated vapor-like memory T cell subpopulation (tcf1+tox-). These data also demonstrate example 9, which example 9 describes the efficacy of anti-PD-1 x 1il7w142h x 1 in promoting accumulation and proliferation of stem cell-like memory T cells in another tumor model.

Example 11: anti-PD-1 x 1il7v x 1 maintains survival of long-term stimulated human T cells and induces proliferation of tcf1+ T cells.

To demonstrate the effect of anti-PD-1 x 1IL7v x 1 on human T cells, the inventors tested the effect of anti-PD-1/IL 7 constructs in an in vitro chronic antigen stimulation model. Human PBMC were stimulated repeatedly every 3 days on CD3CD28 coated plates (3. Mu.g/mL OKT3 and 3. Mu.g/mL CD28.2 antibody). At each stimulation, anti-PD-1 x 1il7v x 1 (anti-PD-1 x 1il7w142h x 1) constructs, isotype control, or anti-PD-1*1 antibodies were added to the cultures. T cell viability and phenotype were assessed by flow cytometry 24 hours after the fifth stimulation.

Fig. 24A shows that anti-PD-1 x 1il7w142h x 1 maintained survival of long-term depleted T cells compared to anti-PD-1 treatment. Phenotypic analysis of T cells (fig. 24B) demonstrated that anti-PD-1 x 1il7v x 1 promoted specific proliferation and maintenance of tcf1+cd8t cell subsets. The tcf1+ T cell population is described as a stem cell-like T cell population capable of self-renewal and long-term effective response. These results can prevent proliferation of T cells that are depleted in primary or secondary resistance to immune tumor therapy or other cancer therapy and in various immune tumor escape situations by restoring the long term effects of solid tumors by re-vibrating TIL with anti-PD-1 x 1 v x 1 in the early stages of cancer (adjuvant or neoadjuvant case).

Example 12: anti-PD-1 x 1il-7v x 1 demonstrated in vivo monotherapy efficacy in different humanized models that were resistant to PD-1 therapy.

In a Triple Negative Breast Cancer (TNBC) model (immunodeficient mice subcutaneously implanted with breast cancer cells MDA-MB 231), mice were humanized with human Peripheral Blood Mononuclear Cells (PBMCs) from 4 different donors, followed by treatment with PBS, anti-PD-1*2 or anti-PD-1 x 1i 7w142h x 1 bifunctional antibodies. anti-PD-1 x 1il7v x 1 reduced tumor growth in all PBMC donors tested, whereas anti-PD-1*2 alone had no effect (fig. 25).

In another humanized mouse model lung cancer model (a 549), the efficacy of anti-PD-1 x 1il7v x 1 relative to anti-PD-1*1 was demonstrated, correlated with increased IFNg secretion in serum of the anti-PD-1*1 treated mice (day 34) (fig. 26). Both models demonstrate that anti-PD-1 x 1il7v can also modulate immune-mediated anti-tumor responses in vivo to a greater extent than anti-PD-1*2.

Example 13: in cynomolgus monkeys, anti-PD-1 x 1il7v x 1 exhibited better pharmacokinetic profile than anti-PD-1 x 1il7wt 1 molecules.

The cynomolgus monkey is given an intravenous injection of one dose of anti-PD-1 x 1il7wt 1 (0.8 mg/kg, 4.01 mg/kg) or one dose of anti-PD-1 x 1il7v 1 (anti-PD-1 x 1il7w142h 1) 0.8mg/kg, 4.01mg/kg or 25 mg/kg. Following injection, serum was collected at various time points to quantify the anti-PD-1 IL7 constructs by ELISA immunoassay using MSD technology. Briefly, human PD1 protein was immobilized and serum anti-PD-1 x 1il7 x 1 antibody was added. ELISA assays were performed using sulfo-labeled anti-human kappa light chain monoclonal antibodies.

Pharmacokinetic data for both constructs were linear and dose dependent. However, better pharmacokinetic profiles were observed with the anti-PD-1 x 1IL7v x 1 construct compared to the anti-PD-1 x 1IL7wt 1 construct (fig. 27) (area under the curve 29.6 versus 108, IL7wt versus IL7v at dose 4.01 mg/kg). Interestingly, anti-PD-1 x 1IL7v x 1, which has low affinity for IL7 receptor, induced CD 8T cell proliferation in vivo until days 10-14, indicating that the biological effect of the drug was beyond pharmacokinetic exposure. These data allow the creation of a new pharmacodynamic model that measures long term effects on T cell subsets in non-human primates and is suitable for human situations: i.e. cd8+ T cells proliferated after only one injection of anti-PD-1 x 1il7v x 1 bifunctional antibody.

Example 14: anti-PD-1 x 1il7v x 1 constructed with the IgG 1N 297A isotype or with the LALA PG IgG1 isotype have the same efficacy in activating pSTAT5 signaling into human T cells.

In examples 1 to 13, the IgG 1N 297A form was used for anti-PD-1*1/cytokine construction. The inventors tested another form of Fc silencing with additional mutations of LALA PG described as completely abrogating ADCC, ADCP and CDC activity, as LALA PG mutations impair binding to FcR receptors.

IL-7R activity against PD-1 x 1IL7W142H x 1 was assessed by pSTAT5 activity (FIG. 28). No difference in activity on CD4 and CD8 human T cells was noted between the two constructs, indicating that the invention can be constructed with different Fc silencing isoforms.

Example 15: anti-PD-1 x 1il7v x 1 constructed with IgG 1N297A isotype or variants to improve FcRn binding or variants with lower charge pHi have the same efficacy of activating pSTAT5 signaling into human T cells.

The inventors designed and compared the biological activity of a number of constructs comprising the novel bifunctional molecules against PD-1 x 1il7w142h x 1 mutant: mutations in the Fc domain to improve FcRn binding (YTE, LS, DHS), or mutations in the anti-PD-1*1 light chain, as described in figure 29. All anti-PD-1/IL 7W142H constructs had high affinity to the PD-1 receptor, similar to the anti-PD-1 x 1IL7W142H x 1n297a antibodies, as shown by the ELISA assay (fig. 29). Such anti-PD-1 x 1i 7w142h 1 mutants comprise VH as defined in SEQ ID No. 24 and IL-7 as defined in SEQ ID No. 5, and VL as defined in SEQ ID No. 28, 88 or 99.

The anti-PD-1/IL 7W142H mutant molecules showed high pSTAT5 activity similar to the anti-PD-1 x 1IL7W142H x 1n297a bifunctional molecule, but less activity on naive T lymphocytes (PD 1-cells) than anti-PD-1 x 1IL-7wt 1 (fig. 30). Based on these observations, mutations in the Fc domain or VL domain support alternative backbones that can be used in the present invention.

Materials and methods

ELISA binding to PD1

For the activity ELISA assay, recombinant hPD1 (Sino Biologicals, beijing, china; reference 10377-H08H) was immobilized on plastic with 0.5 μg/ml carbonate buffer (pH 9.2) and purified antibodies were added to measure binding. After incubation and washing, peroxidase-labeled donkey anti-human IgG (Jackson Immunoresearch; USA; reference 709-035-149) was added and developed by conventional methods.

ELISA antagonists: competition between PDL1 and humanized anti-PD 1

A competition ELISA assay was performed by PD-1:PD-L1 inhibitor screening ELISA assay pairs (Acrobiosystems; USA; reference EP-101). In this assay, recombinant hPDL1 was immobilized on plastic in 2. Mu.g/ml PBS pH7.4 buffer. Purified antibodies (different concentrations) were mixed with 0.66. Mu.g/ml final (fixed concentration) biotinylated human PD1 (Acrobiosystems; USA; reference EP-101) and competitive binding was measured at 37℃for 2 hours. After incubation and washing, peroxidase-labeled streptavidin (Vector Laboratoring; USA; reference SA-5004) was added to detect biotin-PD-1 Fc binding and revealed by conventional methods.

pSTAT5 assay

PBMCs isolated from peripheral blood of human healthy volunteers were incubated with anti-PD-1/IL-7 molecules for 15 min at 37 ℃.

To determine cis-activity, U937 transduced with CD127 and PD-1 was mixed with U937 transduced with cd127+ only. Cells were stained with cell proliferation dye (CPDe 450 or CPDe670, thermosusher) mixed at a 1:1 ratio and treated with test molecules for 15 minutes at 37 ℃. Prior to co-cultivation, each cell subpopulation was labeled with a cell proliferation dye (CPDe 450 or CPDe 670). Cells were then fixed, permeabilized and stained with AF 647-labeled anti-pSTAT 5 (clone 47/Stat5 (pY 694), BD Bioscience). pSTAT5 activation in cd3+ T cell populations was assessed for human PBMCs. For the U937 assay, pSTAT5 activation of U937pd1+cd127+ cells and U937 cd127+ cells was assessed.

Cell binding assays

U937 transduced with CD127 and PD-1 was mixed with U937 transduced with cd127+ only. Cells were stained with cell proliferation dye (CPDe 450 or CPDe670, thermosusher) mixed at a ratio of 1:1. Cells were stained with yellow/dead fixable stain (thermosipher) and then stained with human Fc Block (BD Bioscience) diluted in PBS2% human serum. Cells were then stained with a range of concentrations of the test molecule and antibody display was performed using anti-human IgG-PE antibody (bioleged, clone HP 6017) and analyzed by flow cytometry.

In vivo pharmacokinetics against PD-1/IL7

To analyze pharmacokinetics, a single dose of the molecule was injected into C57bl6JrJ mice (female 6-9 weeks) either intra-orbital or intraperitoneally or intravenously (retroorbital), and the drug concentration in plasma was determined by ELISA using serum containing IgG fusion Il67 diluted with immobilized anti-human light chain antibody (clone NaM76-5F 3). Detection was performed using peroxidase-labeled donkey anti-human IgG (Jackson Immunoresearch; USA; reference 709-035-149) and revealed by conventional methods.

T cell activation assay using Promega cell bioassays

The ability of anti-PD-1 antibodies to restore T cell activation was tested using the Promega PD-1/PD-L1 kit (reference number J1250). Two cell lines were used: (1) Effector T cells (Jurkat which stably express PD-1, NFAT-induced luciferase) and (2) target cells (CHO K1 cells which stably express PDL1 and which are intended to stimulate the surface protein of a cognate TCR in an antigen-independent manner.) when the cells are co-cultured, PD-L1/PD-1 interactions inhibit TCR-mediated activation, thereby blocking NFAT activation and luciferaseActivity. The addition of anti-PD-1 antibodies blocks PD-1 mediated inhibition signals, resulting in NFAT activation and luciferase synthesis and emission of bioluminescent signals. Experiments were performed as suggested by the manufacturer. Serial dilutions of the test molecules were tested. After 4 hours of co-culture of PD-L1+ target cells, PD-1 effector cells and test molecules, bioGlo was performed ^TM Fluorescein substrate was added to the wells and Tecan was used ^TM The luminometer reads the plate.

Proliferation in vivo

A single dose of bifunctional molecule (34 nM/kg) was injected intraperitoneally into C57bl6JrJ mice (female 6-9 weeks) bearing subcutaneous MC38 tumors. Mice were treated with one dose (34 nM/kg) by intraperitoneal injection. On day 4 post-treatment, blood was collected and T cells were stained with anti-CD 45, CD3, anti-CD 8, anti-CD 4 and anti-ki 67 antibodies to quantify proliferation by flow cytometry.

Humanized PD1 knock-in a mouse model

The efficacy of anti-PD-1/IL-7 molecules was evaluated in vivo in a mouse model genetically modified to express human PD-1 (exon 2) in an isogenic immunocompetent. For the in situ mesothelioma model AK7 mesothelial cells (3 e6 cells/mouse) were intraperitoneally injected and then treated at day 4/6/8 with equivalent drug exposure doses [ anti-PD-1*2 (1 mg/kg), anti-PD-1*1/IL-7 x 1mg/kg ]. Injected AK7 cells stably expressed luciferase, producing in vivo bioluminescent signals following intraperitoneal injection of D-luciferin (3 μg/mouse, goldBio, saint Louis MO, USA, reference 115144-35-9). Ten minutes after fluorescein injection, bioluminescence signals were measured by Biospace Imager for 1 minute on the dorsal and ventral sides of the mice. The data were analyzed in photons per second per square centimeter per steradian and represent the average of dorsal and ventral signals. Each group represents the mean +/-SEM of 5 to 7 mice per group. For the liver cancer model, hepa1.6 liver cancer cells were subcutaneously injected, and 2.5e6 cells were in the portal vein. Mice were then treated at day 4/6/8 with equivalent drug exposure doses [ anti-PD-1*2 (1 mg/kg), anti-PD-1*1/IL-7 x 1mg/kg ].

Antibodies and bifunctional molecules

The following antibodies and bifunctional molecules have been used in the different experiments disclosed herein: palbociclizumab (keytrura, merck) nivolumab (Opdivo, bristol-Myers Squibb), and bifunctional molecules disclosed herein comprising an anti-PD 1 humanized antibody comprising a variable heavy chain (VH) as defined in SEQ ID No. 24 and a variable light chain (VL) as defined in SEQ ID No. 28, 88 or 99 or the anti-PD-1 chimeric antibody comprising a heavy chain as defined in SEQ ID No. 71 and a light chain as defined in SEQ ID No. 72.

TABLE 5 test molecules

Construct 1 comprises two anti-PD-1 antigen binding domains and two IL-7W142H variants (construct 1 is also referred to as anti-PD-1 x 2IL-7W142H x 2). This molecule corresponds to the construct tested in examples 1 to 7. This molecule is also known as BICKI-IL-7W142H. Specifically, construct 1 comprises a variable heavy chain (VH) as defined in SEQ ID NO. 24 and a variable light chain (VL) as defined in SEQ ID NO. 28, or an anti-PD 1 chimeric antibody comprising a heavy chain as defined in SEQ ID NO. 71 and a light chain as defined in SEQ ID NO. 72. The molecule also comprises IL7 variants, for example as depicted in SEQ ID NO. 5.

In the examples, the control molecule, designated BICKI-IL-7WT, corresponds to construct 1, but has wild-type IL-7. It comprises the sequence as shown in SEQ ID NO:24 and a variable heavy chain (VH) as defined in SEQ ID NO:28, and a variable light chain (VL) as defined in 28. The molecule has the IgG4S288P isotype.

Another control molecule is anti-PD 1 x 2 (without any IL 7). The molecule comprises a heavy chain as defined in SEQ ID NO. 79 and a light chain as defined in SEQ ID NO. 80.

Construct 2 contained two anti-PD-1 antigen binding domains and a single IL-7W142H variant (construct 2 was also referred to as anti-PD-1 x 2IL-7W142H x 1). Specifically, construct 2 comprises a variable heavy chain (VH) as defined in SEQ ID NO. 24 and a variable light chain (VL) as defined in SEQ ID NO. 28. The molecule comprises in particular a heavy chain as defined by SEQ ID NO:83 (mortar) which binds IL-7W142H or a heavy chain as defined by SEQ ID NO:81 (pestle) and a light chain as defined by SEQ ID NO: 80.

Construct 3 contained a single anti-PD-1 antigen binding domain and a single IL-7W142H variant (construct 3 is also referred to as anti-PD-1 x 1IL-7W142H x 1). Specifically, construct 3 comprises a variable heavy chain (VH) as defined in SEQ ID NO. 24 and a variable light chain (VL) as defined in SEQ ID NO. 28. The molecule comprises a heavy chain as defined in SEQ ID NO. 83 which binds IL-7W142H, an Fc region as defined in SEQ ID NO. 75 and a light chain as defined in SEQ ID NO. 80.

The control construct, designated anti-PD-1*1, was similar to construct 3 but without the IL-7 variant. Such controls comprise a variable heavy chain (VH) as defined in SEQ ID NO. 24 and a variable light chain (VL) as defined in SEQ ID NO. 28. The molecule comprises a heavy chain as defined in SEQ ID NO. 81, an Fc region as defined in SEQ ID NO. 75 and a light chain as defined in SEQ ID NO. 80.

Construct 4 comprises a single anti-PD-1 antigen binding domain and two IL-7W142H variants (construct 4 is also referred to as anti-PD-1 x 1IL-W142H x 2). In particular, construct 4 comprises a variable heavy chain (VH) as defined in SEQ ID NO. 24 and a variable light chain (VL) as defined in SEQ ID NO. 28. The molecule comprises a heavy chain as defined in SEQ ID NO:83 which binds IL-7W142H, an Fc region as defined in SEQ ID NO:76 which binds IL-7W142H and a light chain as defined in SEQ ID NO: 80.

Constructs 2, 3 and 4 were engineered using the IgG1N298A isotype and the amino acid sequences were mutated in the Fc portion to create a pestle on CH2 and CH3 of heavy chain a and a mortar on CH2 and CH3 of heavy chain B. All anti-PD-1 IL-7 and anti-PD-1*1 constructs contained the IgG1N298A mutant isotype, except the anti-PD-1*2 construct (lacking IL-7) and anti-PD-1 x 2IL7WT x 2 (BICKI-IL-7 WT) were constructed from the IgG4S288P isotype.

Description of the constructs used in examples 3 to 8.

Different constructs of the bifunctional antibodies were tested and compared. The following formats were tested: (1) form A (anti-PD-1*2/IL-7*2), (2) form B (anti-PD-1*2/IL-7*1) (3) form C (anti-PD-1*1/IL-7*1 fused to the heavy chain). For form C, the Fc domain comprises CH1 CH2 and a hinge portion. All constructs were engineered with IgGl N298A isoforms and the amino acid sequences were mutated in the Fc portion to produce a pestle on CH2 and CH3 of heavy chain a and a mortar on CH2 and CH3 of heavy chain B. All constructs contained GGGGSGGGGSGGGGS linkers (SEQ ID NO: 70) between the Fc domain and the fused IL-7m protein.

Claims

1. A bifunctional molecule comprising a single antigen binding domain and a single IL-7 variant,

wherein the bifunctional molecule comprises a first monomer comprising an antigen binding domain covalently linked, optionally via a peptide linker, to the N-terminus of a first Fc chain via the C-terminus, and a second monomer comprising a second, complementary Fc chain free of antigen binding domains and free of IL-7 variants;

wherein i) the IL-7 variant is covalently linked to the C-terminus of the first Fc chain, optionally via a peptide linker; or ii) the single antigen binding domain comprises a heavy chain variable chain and a light chain variable chain, and the IL-7 variant is covalently linked to the C-terminus of the light chain;

wherein the antigen binding domain binds to PD-1; and

wherein the IL-7 variant exhibits at least 75% identity with wild-type human IL-7 (wth-IL-7), the wild-type human IL-7 (wth-IL-7) comprises or consists of the amino acid sequence of SEQ ID NO:1, and the IL-7 variant i) reduces the affinity of the IL-7 variant for IL-7 receptor (IL-7R) compared to the affinity of wth-IL-7 for IL-7R, and ii) improves the pharmacokinetics of a bifunctional molecule comprising the IL-7 variant compared to a bifunctional molecule comprising wth-IL-7.

2. The bifunctional molecule of claim 1, wherein the IL-7 variant comprises at least one amino acid mutation selected from the group consisting of: (i) W142G, W142A, W142V, W142C, W142L, W142I, W142M, W142H, W Y and W142F, preferably W142H, W142F or W142Y, (ii) C2S-C141S and C47S-C92S, C S-C141S and C34S-C129S, or C47S-C92S and C34S-C129S, (iii) D74E, D Q or D74N, iv) Q11E, Y12F, M17L, Q E and/or K81R; or any combination thereof, and the amino acid numbers are shown as SEQ ID NO: 1.

3. The bifunctional molecule of claim 1 or 2, wherein the IL-7 variant is linked to the C-terminus of the first Fc chain, preferably via its N-terminus.

4. A bifunctional molecule according to any one of claims 1 to 3 wherein the IL-7 variant comprises an amino acid substitution selected from W142H, W142F and W142Y, the amino acid numbering as shown in SEQ ID No. 1.

5. The bifunctional molecule of any one of claims 1-3, wherein said IL-7 variant comprises the amino acid substitution W142H.

6. A bifunctional molecule according to any one of claims 1 to 3 wherein the IL-7 variant comprises or consists of the amino acid sequence shown in SEQ ID NOs 2 to 15.

7. A bifunctional molecule according to any one of claims 1 to 3 wherein the IL-7 variant comprises or consists of the amino acid sequence shown in SEQ ID No. 5.

8. The bifunctional molecule of any one of claims 1 to 7, wherein the bifunctional molecule comprises a heavy chain constant domain, preferably an Fc domain, of a human IgG1, optionally with a substitution or combination of substitutions selected from the group consisting of: T250Q/M428L; M252Y/S254T/T256 E+H2433K/N434F; E233P/L234V/L235A/G236A+A327G/A330S/P331S; E333A; S239D/A330L/I332E; P257I/Q311; K326W/E333S; S239D/I332E/G236A; N297A; L234A/L235A; n297A+M252Y/S254T/T256E; n297A+N298A+M252Y/S254T/T256 E+K25A, K322A, K444E, K444D, K444G, K444S, P329G, L A/L235A/P329G, M428 309 7452 309 74311 823 8238 A+N434S and L309D+Q311H+N434S, preferably selected from N297A optionally in combination with M252Y/S254T/T256E, and L234A/L235A or L234A/L235A/P329G.

9. The bifunctional molecule of any one of claims 1-7, wherein the bifunctional molecule according to the invention comprises a heavy chain constant domain, preferably an Fc domain, of human IgG1, optionally with a substitution or combination of substitutions selected from the group consisting of: T250Q/M428L; M252Y/S254T/T256 E+H2433K/N434F; E233P/L234V/L235A/G236A+A327G/A330S/P331S; E333A; S239D/A330L/I332E; P257I/Q311; K326W/E333S; S239D/I332E/G236A; N297A; L234A/L235A; n297A+M252Y/S254T/T256E; K322A and K444A, preferably selected from N297A optionally in combination with M252Y/S254T/T256E, and L234A/L235A.

10. The bifunctional molecule of any one of claims 1-7, wherein the bifunctional molecule comprises a heavy chain constant domain, preferably an Fc domain, of human IgG4, optionally with a substitution or combination of substitutions selected from the group consisting of: S228P; L234A/L235A, S P+M252Y/S254T/T256+K444A, P329G, K444E, K444D, K444G, K444S and L234A/L235A/P329G.

11. The bifunctional molecule of any one of claims 1-7, wherein the bifunctional molecule according to the invention comprises a heavy chain constant domain, preferably an Fc domain, of human IgG4, optionally with a substitution or combination of substitutions selected from the group consisting of: S228P; L234A/L235A, S228P+M252Y/S254T/T256E and K444A.

12. The bifunctional molecule of any one of claims 1-7, wherein the Fc domain is IgG1 or IgG4 comprising a mutant LALA (L234A/L352A) or LALA PG (L234A/L235A/P329G).

13. The bifunctional molecule of any one of claims 1-12, wherein the first Fc chain and the second Fc chain form a heterodimeric Fc domain, in particular a pestle-in-mortar heterodimeric Fc domain.

14. The bifunctional molecule of claim 13, wherein the first Fc chain is a mortar or H chain and comprises the substitutions T366S/L368A/Y407V/Y349C and N297A, and the second Fc chain is a mortar or K chain and comprises the substitutions T366W/S354C and N297A.

15. The bifunctional molecule of claim 13, wherein said second Fc chain comprises or consists of SEQ ID NO:75 and/or said first Fc chain comprises or consists of SEQ ID NO: 77.

16. The bifunctional molecule of any one of claims 1-15, wherein the bifunctional molecule comprises a first monomer comprising an antigen binding domain covalently linked via a C-terminus to the N-terminus of a first heterodimeric Fc chain optionally via a peptide linker covalently linked via a C-terminus to the N-terminus of the IL-7 variant, and a second monomer comprising a complementary second heterodimeric Fc chain devoid of an antigen binding domain.

17. The bifunctional molecule of any one of claims 1-15, wherein the IL-7 variant is fused to the antigen binding domain or the Fc domain by a peptide linker selected from the group consisting of: GGGGS (SEQ ID NO: 68), GGGGSGGGS (SEQ ID NO: 67), GGGGSGGGGS (SEQ ID NO: 69) and GGGGSGGGGSGGGGGGS (SEQ ID NO: 67)ID NO: 70), preferably (GGGGS) ₃ 。

18. The bifunctional molecule of any one of claims 1-15, wherein the IL-7 variant is fused to the antigen binding domain or the Fc domain via a peptide linker of SEQ ID 70.

19. The bifunctional molecule of any one of claims 1-18, wherein said antigen binding domain is a Fab domain, fab', single chain variable fragment (scFV), or single domain antibody (sdAb).

20. The bifunctional molecule of any one of claims 1-18, wherein said antigen binding domain is a Fab domain or a Fab'.

21. The bifunctional molecule of any one of claims 1 to 20, wherein said antigen binding domain is derived from an antibody selected from the group consisting of: palbociclib, nivolumab, pidil mab, cimetidine Li Shan, carlizumab, AUNP12, AMP-224, age-2034, BGB-a317, spatazumab, MK-3477, SCH-900475, PF-06801591, JNJ-63723283, ji Nuoli mu mab, LZM-009, BCD-100, SHR-1201, BAT-1306, AK-103, MEDI-0680, MEDI0608, JS001, BI-754091, CBT-501, incsler 1210, TSR-042, GLS-010, AM-0001, STI-1110, age 2034, MGA012 or IBI308, 5C4, 17D8, 2D3, 4H1, 4a11, 7D3 and 5F4.

22. The bifunctional molecule of any one of claims 1 to 20, wherein said antigen binding domain is derived from an antibody selected from the group consisting of: palbociclib, nivolumab, pidil mab, cimetidine Li Shan, carlizumab, spatazumab and Ji Nuoli mu mab.

23. The bifunctional molecule of any one of claims 1 to 20, wherein the antigen binding domain is derived from palbociclizumab or nivolumab.

24. The bifunctional molecule of any one of claims 1 to 20, wherein the antigen binding domain comprises or consists essentially of: (i) A heavy chain comprising CDR1 of SEQ ID NO:51, CDR2 of SEQ ID NO:53 and CDR3 of SEQ ID NO:55, 56, 57, 58, 59, 60, 61 or 62; and (ii) a light chain comprising CDR1 of SEQ ID NO. 64, 65, 89, CDR2 of SEQ ID NO. 66 and CDR3 of SEQ ID NO. 16 or 90.

25. The bifunctional molecule of any one of claims 1 to 20, wherein the antigen binding domain comprises or consists essentially of: (i) A heavy chain comprising CDR1 of SEQ ID NO. 51, CDR2 of SEQ ID NO. 53 and CDR3 of SEQ ID NO. 61; and (ii) a light chain comprising CDR1 of SEQ ID NO:65, CDR2 of SEQ ID NO:66 and CDR3 of SEQ ID NO: 16.

26. The bifunctional molecule of any one of claims 1-20, wherein said antigen binding domain comprises or consists essentially of:

(b) A light chain variable region (VL) comprising or consisting of the amino acid sequence of SEQ ID NO. 27, SEQ ID NO. 28, SEQ ID NO. 88 or SEQ ID NO. 99.

27. The bifunctional molecule of any one of claims 1-20, wherein the antigen binding domain comprises or consists essentially of the heavy chain variable region (VH) of SEQ ID No. 24 and the light chain variable region (VL) of SEQ ID No. 28.

28. The bifunctional molecule of any one of claims 1-20 or 26, 27, wherein the antigen binding domain comprises or consists essentially of the heavy chain variable region (VH) of SEQ ID No. 24 and the light chain variable region (VL) of SEQ ID No. 28, and the IL-7 variant comprises the amino acid substitution W142H, the amino acid numbering being as shown in SEQ ID No. 1, preferably as defined in SEQ ID No. 5.

29. The bifunctional molecule of any one of claims 1-20 or 26-28, wherein:

30. The bifunctional molecule of claim 29, wherein the bifunctional molecule further comprises a peptide linker of SEQ ID NO. 70.

31. The bifunctional molecule of any one of claims 1-20, wherein the bifunctional molecule comprises a first monomer of SEQ ID No. 83, a second monomer of SEQ ID No. 75 and a third monomer of SEQ ID No. 37, 38, 80, 100 or 101, preferably SEQ ID No. 38 or 80.

32. The bifunctional molecule of any one of claims 1-20, wherein the bifunctional molecule comprises a first monomer comprising or consisting of SEQ ID No. 83, a second monomer comprising or consisting of SEQ ID No. 75, or 75, and a third monomer comprising or consisting of SEQ ID No. 80, or 80.

33. An isolated nucleic acid sequence or set of isolated nucleic acid molecules encoding a bifunctional molecule of any one of claims 1 to 32.

34. A host cell comprising the isolated nucleic acid of claim 33.

35. A pharmaceutical composition comprising the bifunctional molecule of any one of claims 1 to 32, the isolated nucleic acid of claim 33, or the host cell of claim 34, optionally containing a pharmaceutically acceptable carrier.

36. The bifunctional molecule of any one of claims 1 to 32, the isolated nucleic acid of claim 33, the host cell of claim 34 or the pharmaceutical composition of claim 35 for use as a medicament, in particular for the treatment of cancer or infectious disease.

37. A bifunctional molecule, nucleic acid, host cell, or pharmaceutical composition according to claim 36 for use in treating cancer or viral infection by stimulating effector memory stem cell-like T cells.

38. A method of treating cancer or a viral infection in a subject in need thereof, wherein the method comprises administering a therapeutically effective amount of the bifunctional molecule of any one of claims 1 to 32, the isolated nucleic acid of claim 33, the host cell of claim 34, or the pharmaceutical composition of claim 35, thereby stimulating effector memory stem cell-like T cells.

39. The bifunctional molecule, nucleic acid, host cell, or pharmaceutical composition of claim 36 or 37, or the method of claim 38, wherein the cancer is selected from the group consisting of: hematopoietic cancers, solid cancers, carcinomas, cervical cancers, colorectal cancers, esophageal cancers, gastric cancers, gastrointestinal cancers, head and neck cancers, renal cancers, liver cancers, lung cancers, lymphomas, gliomas, mesothelioma, melanoma, gastric cancers, cancers induced by urinary tract cancer environments, metastatic or non-metastatic cancers, melanoma, malignant mesothelioma, non-small cell lung cancers, renal cell cancers, hodgkin's lymphoma, head and neck cancers, urothelial cancers, colorectal cancers, hepatocellular carcinoma, small cell lung cancers, metastatic merck cell cancers, gastric or gastroesophageal cancers, cervical cancers, hematopoietic lymphomas, angioimmunoblastic T cell lymphomas, myelodysplastic syndromes, acute myeloid leukemia, kaposi's sarcoma; cervical cancer, anal cancer, penile cancer and vulvar squamous cell carcinoma associated with human papillomavirus, and oropharyngeal cancer; b-cell non-hodgkin lymphomas (NHL), including diffuse large B-cell lymphomas, burkitt's lymphomas, plasmablasts, primary central nervous system lymphomas, HHV-8 primary exudative lymphomas, classical hodgkin lymphomas, and lymphoproliferative diseases associated with epstein-barr virus (EBV) and/or kaposi's sarcoma herpesvirus; hepatocellular carcinoma associated with hepatitis b and/or c virus; merck cell carcinoma associated with merck cell polyoma virus (MPV); and cancers associated with Human Immunodeficiency Virus (HIV) infection.

40. The bifunctional molecule, nucleic acid, host cell, or pharmaceutical composition of claim 36 or 37, or the method of claim 38, wherein the viral infection is caused by a virus selected from the group consisting of: HIV, hepatitis viruses such as hepatitis a, b or c, herpes viruses such as VZV, HSV-1, HAV-6, HSV-II, CMV and epstein-barr virus, adenovirus, influenza virus, flavivirus, epstein barr virus, rhinovirus, coxsackievirus, coronavirus, respiratory syncytial virus, mumps virus, rotavirus, measles virus, rubella virus, parvovirus, vaccinia virus, HTLV virus, dengue virus, papilloma virus, mollusc virus, polio virus, rabies virus, JC virus and arbovirus encephalitis virus.

41. The bifunctional molecule, nucleic acid, host cell, or pharmaceutical composition of claim 36, 37, 39, or 40, for use in combination with a therapeutic agent or therapy selected from the group consisting of: chemotherapy, radiation therapy, targeted therapy, anti-angiogenic agents, hypomethylating agents, cancer vaccines, epitopes or neoepitopes from tumor antigens, bone marrow checkpoint inhibitors, immunotherapy and HDAC inhibitors.

42. The bifunctional molecule, nucleic acid, host cell, or pharmaceutical composition of claim 41, wherein the therapeutic agent is an immune checkpoint blocker or activator of adaptive immune cells (T and B lymphocytes) selected from the group consisting of: anti-CTLA 4, anti-CD 2, anti-CD 28, anti-CD 40, anti-HVEM, anti-BTLA, anti-CD 160, anti-TIGIT, anti-TIM-1/3, anti-LAG-3, anti-2B 4, anti-OX 40, anti-CD 40 agonist, CD40-L, TLR agonist, anti-ICOS, ICOS-L and B cell receptor agonist.