NZ618316B2 - Neutralizing prolactin receptor antibody mat3 and its therapeutic use - Google Patents

Abstract

Disclosed is an antibody or antigen-binding fragment thereof which antagonises prolactin receptor-mediated signalling, whereby the antibody or antigen-binding fragment thereof comprises a variable heavy chain containing the CDR sequences of FSSYWMHW, SDIARLSSYTNYADSVKGR, and ARGLDARRMDY and a variable light chain containing the CDR sequences of TGSSSNIGAGYVVH, RNNQRPS, and CAAWDDSLNGWL. Also disclosed is the use of the above-described antibody or antigen-binding fragment in preparation of a medicament for the treatment and/or prevention of endometriosis and adenomyosis, benign breast disease and mastalgia, or anti-oestrogen-resistant breast cancer. le light chain containing the CDR sequences of TGSSSNIGAGYVVH, RNNQRPS, and CAAWDDSLNGWL. Also disclosed is the use of the above-described antibody or antigen-binding fragment in preparation of a medicament for the treatment and/or prevention of endometriosis and adenomyosis, benign breast disease and mastalgia, or anti-oestrogen-resistant breast cancer.

Description

Neutralizing prolactin receptor antibody Mat3 and its therapeutic use The present invention is directed towards the prolactin receptor antibody Mat3 and es recombinant antigen-binding regions of the antibody Mat3 and functional fragments containing such antigen-binding regions, that specifically bind and neutralize the prolactin receptor, nucleic acid ces encoding the foregoing antibody, vectors containing the same, pharmaceutical compositions ning them and their use in the treatment or prevention of endometriosis and other diseases which benefit from inhibition of prolactin receptor ed signalling. tin (PRL) is a polypeptide hormone composed of 199 amino acids. PRL belongs to the growth hormone (GH), placental lactogen (PL) family of polypeptide hormones and is synthesized in lactotroph cells of the pituitary and in several extrapituitary s such as lymphocytes, mammary epithelial cells, the myometrium, and the prostate. Two different promoters regulate pituitary and extrapituitary PRL synthesis (BioEssays 28:1051-1055, 2006).

PRL binds to the PRL receptor (PRLR), a single transmembrane receptor belonging to the class 1 cytokine receptor superfamily (Endocrine Reviews 19:225-268, 1998). The PRLR exists in three different isoforms, the short, the long, and the intermediate form that can be distinguished by the length of their cytoplasmic tails. Upon ligand binding, a sequential process leads to PRLR activation. PRL interacts via its binding site 1 with one PRLR molecule and then attracts via its g site 2 a second or molecule leading to an active dimer of PRLRs. PRLR dimerization leads to the predominant activation of the JAK/STAT (Janus /Signal transducers and activators of transcription) pathway. Upon receptor dimerization, JAKs (predominantly JAK2) ated with the receptor, transphosphorylate and activate each other. In addition the PRLR is also phosphorylated and can bind to SH2-domain containing proteins such as STATs. Receptor bound STATs are subsequently phosphorylated, dissociate from the or and translocate to the nucleus where they stimulate transcription of target genes. In addition, activation of the Ras—Raf—MAPK pathway and tion of the cytoplasmic src kinase by PRLRs have been described (for review Endocrine Reviews 19: 225-268, 1998).

PRLR-mediated signalling plays a role in a variety of ses such as mammary gland development, lactation, reproduction, mammary and prostate tumor growth, autoimmune diseases, general growth and metabolism, and immunomodulation (Endocrine Reviews 19: 225-268, 1998; Annu. Rev. Physiol. 64: 47-67, 2002).

Currently, there is no medication available that enables complete interference with PRLR-mediated ling beside the inhibition of pituitary PRL secretion by use of bromocriptine and other dopamine receptor 2 ts (Nature Clinical Practice Endocrinology and Metabolism 2(10): 571-581, 2006). These agents, however, do not suppress extrapituitary PRL synthesis that can compensate successfully for the inhibition of pituitary PRL synthesis leading to almost unimpaired ediated 1O signalling rine Reviews -268, 1998). Therefore it is not surprising that dopamine type 2 receptor agonists were not beneficial in ts suffering from breast cancer or autoimmune diseases such as systemic lupus or rheumatoid arthritis (Breast Cancer Res. Treat. 14:289-29, 1989; Lupus 7:414-419, 1998) although prolactin has been implicated in these diseases. Local prolactin synthesis in breast cancer cells or lymphocytes which plays a l role in mammary carcinoma or autoimmune diseases, tively, was not blocked by dopamine receptor agonists.

Antibodies binding to PRLR for breast cancer diagnosis were described in W02003/004989 (lVlillenium Pharmaceuticals) for the first time. In said 04989 numerous genes and corresponding proteins including PRLR being overexpressed in several breast tumor tissues were regarded as suitable markers for early detection of malignancy. ln W003/008583, focussing on lymphoma and leukemia, carcinomaassociated genes and ns are described including PRLR.

Furthermore, in WO2006/110585 (Novartis) PRLR over-expression as a cancer marker and the use of PRLR-specific dies for diagnosis and treatment of breast cancer and other cancer types (lung, prostate and skin cancer) were described. This time, monoclonal antibodies with antagonistic activity were claimed based on two experimental evidences: a) blocking of the PRLR sion by PRLR-specific siRNA in breast cancer MCF7 cells led to inhibition of proliferation of these cells and b) prolactin induces STATS and MAPK orylation in breast cancer cells such as T47D. r, neither any evidence was provided that a monoclonal antibody indeed inhibited proliferation of breast cancer cell lines nor any concrete antibody was disclosed.

The first in vivo proof of concept that PRLR antagonists successfully interfere with breast cancer development has been published in 1988. In the DMBA mouse breast tumor model, a monoclonal PRLR antibody led to reduced incidence of mammary tumors (Am J Pathol 133:589—595,1988).

First PRLR antibodies, claimed for the prevention and treatment of breast cancer, were described in US 2007/0269438 (Biogen). The expression products (antibodies) from five hybridoma cell lines were bed by their ability to tightly bind breast cancer cell lines T47D and MCF7 and to block PRL-mediated signalling (STAT5—, MAPK-, AKT— phosphorylation). However, no in vivo proof of concept has been disclosed. Moreover, no evidence beyond the state—of—the-art knowledge has been ed for the ent 1O that especially after the patient’s cancer become trogen-independent, the anti- PRLR antibody may be stered to the patient.

A second set of onal PRLR-specific antibodies together with disclosed primary sequences was described in (Novartis). gh these antibodies were claimed as therapeutic agents for breast, lung and prostate cancer, a lymphoma model served to show the antiproliferative effect of these agents in vivo.

On the other hand, peptidergic PRLR antagonists that are derived from prolactin and that carry an inal deletion and a point mutation (e.g. delta1-9G129R prolactin) also behave as antagonists of the PRLR, however they suffer from reduced ife time (15-20 min) and low potency if compared to prolactin (Pituitary 6:89-95,2003).

Therefore, neutralising PRLR antibodies are superior especially with regard to the inhibition of enhanced autocrine prolactin signalling that plays a role in breast cancer and prostate .

The role of ediated signalling was also investigated in the context of the benign disease endometriosis. In one study the expression pattern of the PRLR in endometriotic samples and eutopic endometrium from endometriosis patients was analysed (Acta Obstet Gynecol Scand 81:5-10, 2002) during the mid-late proliferative phase of the menstrual cycle. it was demonstrated that the PRLR mRNA was present in the eutopic endometrium in 79% of the analysed endometriosis patients, whereas it was absent in the endometriotic s in 86% of the endometriosis patients. These data suggested a possible differential regulation of PRLR expression between normal and endometriotic tissue. However, from these expression data it cannot be ded that inhibition of the PRLR might represent a suitable triosis therapy — especially since the PRLR was not found to be expressed in the endometriotic lesions (Acta Obstet Gynecol Scand 81 :5-10, 2002).

In conclusion, although PRLR-mediated ling plays a role in a variety of cellular processes, very few and partially contradictory results have been disclosed demonstrating the therapeutic value of PRLR antagonism for most of the benign diseases including endometriosis.

Many data have been published indicating that PRLR might play a ive role in 1O breast cancer. And conceptually, potent PRLR antagonists might be riate agents to demonstrate the therapeutic value of PRLR inhibition for breast cancer.

Nevertheless, no in vivo proof of concept has been ed up to now that PRLR blockade indeed leads to inhibition of tumor growth (except ma treatment and inhibition of breast cancer development) and moreover that antagonistic PRLR antibodies can be used for the treatment of benign diseases which benefit from blockade of PRLR signalling. Therefore, the dies currently available cannot be used in predictive models which allow pre-clinical proof-of—concept studies.

There is a need for antibodies which bind with high affinity to the PRLR in human, monkey and mouse without binding competitively to PRL and this way neutralize the PRLR-mediated signalling in all three species, and which allow to perform pre-clinical proof-of—concept s in mouse as well as - at reasonable doses - also in monkey.

Therefore the underlying m of the present invention lies in the provision of new PRLR antibodies which can be used in predictive models which allow pre—clinical proof of concept studies and which can be used for treatment of diseases which benefit from blockade of prolaction receptor signalling.

The problem is solved by the provision of the new antibody Mat3. it has now been found that said antibody is surprisingly specific to and has a high affinity for PRLR in human, monkey and mouse in biochemical as well as cellular g studies without binding competitively to PRL and this way neutralizes the PRLR- mediated signalling in all three species, in contrast to those antibodies as disclosed in , which bind mpetitively to PRL such as HE06642. This way, said antibody enables to perform inical proof-of—concept studies in mouse as well as - at reasonable doses - also in monkey. Moreover, it has now been found that said WO 63932 antibody can deliver a therapeutic benefit to the subject by being more potent and more closely related to human germline ces and thus offers the opportunity of an improved side-effect profile, i.e. reduced risk of immunogenicity due to reduced dosage and increased similarity to human germline sequences, compared to those dies as disclosed in , which bind non-competitively to PRL such as HE06642.

The novel Mat3 dy is preferably cross-reactive to PRLR from different s such as Macaca mulatta (rhesus monkey) and Macaca fascicularis (cynomolgus), Mus 1O musculus (mouse) and Homo sapiens (human). Cross-reactivity here means that the affinities (KD values) and cell-binding EC50 values of said antibody to human, monkey and mouse PRLR are below 10 x 109 M (see Table 1, examples 9, 10, 13 and 14) and proliferation inhibiton |C50 values are below 20 x 10'9 M (see examples 1 to 3). The present invention is based on the ery of the novel antibody Mat3 which can deliver a therapeutic benefit to the subject (seqences of the novel antibody are as in SEQ ID NO: 1-10). The antibody of the ion, which may be most preferably fully human with very close relationship to human germline sequences or which may be humanized or chimeric or human engineered variants thereof carrying the CDRs of the fully human version, can be used in many contexts which are more fully described herein.

To show superiority in potency and human-monkey—mouse cross-reactivity of said antibody over the most deeply characterized known antibody from g mpetitively to PRL, in in vitro proliferation studies the said antibody has been compared with HE06642 from WO 22295 (Example 1-3). The here ned HE06642 or HE06.642 or 06.642 contains the variable domains SEQ ID N03: 14 and 15, which are identical to the sequences of he06.642-2 in WO 2008/022295. 3O The antibody Mat3 was characterized in several cellular systems to determine its species specificity and its potency as well as efficacy in different readout paradigms addressing the inactivation of PRLR-mediated ling and proliferation. Proliferation assays were performed in Ba/F cell lines either stably transfected with the human PRLR (Example 1), the murine PRLR (Example 2) or the rhesus PRLR (Example 3). Antibody Mat3 completely inhibited eration of cells carrying the human, the murine, and the rhesus PRLR (Example 1-3). Antibody HE06642 () was inactive at the cells carrying the murine PRLR and showed strongly reduced activity at the rhesus PRLR—cells if compared with Mat3. dy Mat3 was also more potent at the human PRLR than antibody 42. There is also evidence that Mat3 inhibits rat NBZ lymphomy cell proliferation with higher potency than HE06422. In addition to cellular proliferation , luciferase reporter assays were performed using HEK293 cell lines stably transfected with either the human or murine PRLR (Example 12) and transiently transfected with a luciferase reporter gene under the control of LHRE’s (lactogenic hormone response elements). Using these systems, it could be confirmed that a promoter dependent on PRLR-mediated signalling is switched off in the presence of 1O Mat3. The inability of the antibody HE06.642 to efficiently block murine ediated signalling became evident again.

In conclusion, antibody Mat3 is therefore suitable for testing the inhibition of PRLR- mediated signalling in murine and monkey models.

The antibody ns variable domains being more similar to translated human germline V-genes than HE06642. Figure 6 shows that the VH and VL domain are each 90% identical to the translated human germline heavy chain V and lambda light chain V genes Z database; Retter l, Althaus HH, MUnch R, Miller W: VBASEZ, an integrative V gene database. Nucleic Acids Res. 2005 Jan 1;33 (Database issue):D671- 4]. HE06642 ts 89% identity to the most similar translated VH germline sequence and only 80% identity to the most similar translated germline kappa light chain V sequence found in VBASEZ. This finding offers the unity of having a lower immunogenicity risk when treating patients with Mat3.

Binding studies of Mat3 and 2 with the extracellular domains of human, monkey and mouse PRLR te that both antibodies interact with these purified domains (see below, Example 10 and Table 1). However, when these domains are exposed on cell surfaces more pronounced differences between Mat3 and HE06642 can be observed.

Most strikingly, HE06642 does not bind murine PRLR when Ba/F cells express this receptor, while lVlat3 does (Table 2, and Figure 5, and Example 9). This finding is consistent with the observation that Mat3 blocks murine PRLR—mediated signalling and proliferation in contrast to HE06642. A peptide scan with the extracellular domain of the human PRLR, which is bound by Mat3 and HE06642 when purified as well as when exposed on cell surfaces, reavealed that Mat3 binds to the subdomain 82 (Example 11) such as 642 as ed previously (). This scan additionally showed that there are differences in binding to the 82 domains between Mat3 and Thus provided herein is an antibody or antigen-binding fragment thereof which antagonizes prolactin receptor-mediated signaling, whereby the antibody or nbinding fragment f comprises a variable heavy chain containing the CDR sequences of SEQ ID NO: 5, 6 and 7 and a variable light chain containing the CDR sequences of SEQ ID NO: 8, 9, and 10.

In another embodiment of the present invention the Mat3 consists of an antigen—binding region whereby the affinity to the extracellular domain of PRLR from human, monkey and mouse is at least 100 nM, preferably less than about 100 nM, more preferably less than about 30 nM, even more preferred less than about 10 nM.

In another embodiment the antibody Mat3 consists of an antigen—binding region that binds specifically to one or more regions of the extracellular domain of human PRLR and whereby the affinity is at least 10 nM, more preferable less than about 1nM.

Also object of the present invention is the entioned Mat3, wherein the heavy chain constant domains determine a modified or unmodified lgG1, lgG2, lgGB or lgG4.

Table 1 provides a summary of dissociation constants (affinities) and dissociation rates of the dy Mat3 of the invention, as determined by surface plasmon resonance (Biacore) with monomeric extracellular domains (amino acid 1- to 210) of human PRLR (SEQ ID NO: 12), rhesus and cynomolgus PRLR (SEQ ID NO: 11, whereby the Fc—His fusion has been removed by proteolytic Factor Xa digestion) and murine PRLR (SEQ ID NO: 13) on the ly immobilized antibody (Example 10).

Table 1: Monovalent dissociation constants and dissociation rates of the extracellular domain of human, /cynomolgus monkey and mouse PRLR expressed in HEK293 cells determined for Mat3 as human lgG molecule by surface plasmon resonance (see Example 10) Human PRLR /Cynomolgus Mouse PRLR KD [M] 0.9x10'9 Kd [1Is] '4 The affinities disclosed for 2 in are 2.6 x 10"9 M on the ellular domain of human PRLR, 38.9 x 10'9 M on the corresponding domain of cynomolgus PRLR and 2.7 x 109 M on the ponding domain of murine PRLR.

The cell-based affinity of the antibody Mat3 was determined by fluorescence-activated cell sorting (FACS) combined with Scatchard analysis (Example 9).

WO 63932 Table 2 denotes the binding strength of Mat3 as human IgGZ molecule on the HEK293 cell line stably transfected with human and rhesus monkey PRLR, respectively.

Table 2: Cell-based binding potency of anti-PRLR antibody Mat3 in IgGZ format determined by FACS on the HEK293 cell line stably transfected with human and Rhesus monkey PRLR, respectively (see e 9) Antibody ECso [M] HEK293 expressing BaIF expressing human PRLR rhesus monkey PRLR 2.94 X 10'9 ANTIBODY GENERATION 1O To isolate a panel of antibodies able to onally block the human and murine PRLR, two formats of the tic human antibody phage display library called n-CoDeR® from Bioinvent (Sijderlind et al. 2000, Nature BioTechnology. 18, 852-856.), expressing scFv and Fab fragments, respectively, were igated in parallel. The s used for scFv or Fab selection were the soluble ECD of human PRLR (amino acid positions 1 to 210 of SEQ ID NO. 12) and mouse PRLR (amino acid positions 1 to 210 of SEQ ID NO: 13), applied as biotinylated (NHS-LC biotin, Pierce) and as otinylated variant as well as the human breast cancer cell line T47D expressing PRLR.

A combination of various approaches in display technology (PDT) was used to isolate high affinity, PRLR-specific, human monoclonal antibodies, by a combination of protein and whole cell pannings and through the development of specific tools. The panning tools and screening methods include the ECD of the human and mouse PRLR recombinantly expressed in fusion with an F0 domain (R&D Systems, catalogue no. 1167-PR and 1309-PR, respectively; pos. 1-216 of SEQ ID NO: 12 and 13, respectively, each fused to the human IgG1 Fc domain, pos. 100 to 330 of human IgG1), the extracellular domain of the human PRLR recombinantly expressed in fusion with a six- histidine tag (SEQ ID NO: 12), the HEK293 and the murine lymphoma cell line Ba/F each stably transfected with human and murine PRLR, respectively, and the breast cancer cell line T47D and the rat lymphoma cell Nb2 each naturally expressing PRLR as well as the development of panning procedures and screening assays capable of identifying neutralizing antibodies that preferentially bind to PRLR displayed on the cell surface and that are cross-reactive to RLR from mouse.

Screening was performed by first identifying binders for human PRLR and ally mouse PRLR in ELISA tests using recombinantly expressed ns. The combination of these specific methods allowed the isolation of — amongst others - the antibody “005- CO4”.

By affinity maturation of “005-004” on the extracellular domains of human PRLR and murine PRLR, beneficial substitutions were identified according to the procedure described in Example 8. y, individual substitutions cial for improved affinity 1O were evaluated regarding their influence on thermostability of the antibody. Especially, cooperative unfolding of the Fab domain during denaturation of the matured antibodies (e. g. by termperature elevation) should have been ensured (reference regarding cooperative unfolding: isberger, D. et al., J. Mol. Biol. 2005: 347, 773—789). The dy Mat3 resulted from the above described antibody ery and maturation approach.

E VARIANTS Antibodies of the invention are not limited to the specific peptide sequences provided . Rather, the invention also embodies variants of these polypeptides. With reference to the instant disclosure and conventionally available technologies and references, the skilled worker will be able to prepare, test and utilize functional variants of the antibodies disclosed herein, while appreciating that variants having the ability to bind und to functionally block PRLR fall within the scope of the present invention.

A variant can include, for e, an antibody that has at least one altered complementarity determining region (CDR) (hyper-variable) and/or framework (FR) (variable) domain/position, vis-a-vis a peptide sequence sed . To better illustrate this concept, a brief description of antibody structure follows.

An antibody is composed of two peptide chains, each containing one (light chain) or three (heavy chain) constant domains and a variable region (VL, VH), the latter of which is in each case made up of four FR regions (VH: HFR1, HFR2, HFR3, HFR4; VL: LFR1, LFR2, LFR3, LFR4) and three interspaced CDRs (VL: LCDR1, LCDR2, LCDR3; VH: HCDR1, HCDRZ, HCDRB). The n—binding site is formed by one or more CDRs, yet the FR regions provide the structural framework for the CDRs and, hence, play an ant role in antigen binding. By altering one or more amino acid residues in a CDR or FR region, the skilled worker ely can generate mutated or diversified antibody sequences, which can be screened against the antigen, for new or improved properties, for e.

Figure 4 provides the schemes for numbering each amino acid position in the variable domains VL and VH. Tables 3 (VH) and 4 (VL) ate the CDR regions for antibody Mat3 of the invention and e amino acids at a given position to a corresponding consensus or “master gene” sequence, in which the CDR regions are marked with ‘X’.

Table 5 and 6 help to assign the SEQ ID Numbers to the antibodies, antibody fragments and PRLR variants provided in this invention.

Table 3: VH Sequence of antibody Mat3 including CDR annotation I—HCDRl——I | MatE VH EVQLLESGGG LVQPGGSLRL SCAASGFTFS S.YNMHWVRQ APGKGLEWVS Consensus EVQLLESGGG LVQPGGSLRL SCAASCFTxx yoooo¢c<veo APGKGLEWVX ————HCDR2 —————————— | |— Mat3 VH DIARL.SSYT NYADSVKGRF TISRDNSKNT LYLQMNSLRA EDTAMYYCAR Consensus xoemyxxxxx XXKKKKKKXF TISRDNSKNT SLRA EDTAVYTCXX ——HCDR3 ——————— | Mat3 VH ... R RMDYWGQGTL VTVSS Consensus mom moon WVSS Table 4: VL Sequence of dy Mat3 including CDR tion I———LCDR1————— | Mat3 VL QSVLTQPPSA SGTPGQRVTI SNIG AGYVVHwYQQ LPGTAPKLLI Consensus QSVLTQPPSA SGTPGQRWI SEW moo LPGTAPKLLI |LCDR2| |————LCDR3—— Mat3 VL YRNNQRPSGV PDRFSGSKSG TSASLAISGL RSEDEADYYC LNG.

Consensus YWGV PDRFSGSKSG TSASLAISGL RSEDEADWX WOO-(X Mat3 VL 'N'LFGGGTKLT VLGQ Consensus XXFGGGTKLT VLGQ :_> 29302032 8m ,w H .:----.-.-..---.E.......

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H m The skilled worker can use the data in Tables 3, 4 and 5 to design peptide variants that are within the scope of the present invention. It is red that variants are constructed by changing amino acids within one or more CDR regions; a t might also have one or more altered framework regions (FR). For example, a peptide FR domain might be altered where there is a ion in a residue compared to a germline sequence.

Furthermore, variants may be ed by maturation, i. e. by using one antibody as starting point for optimization by diversifying one or more amino acid residues in the antibody, preferably amino acid residues in one or more CDRs, and by screening the 1O resulting collection of dy variants for variants with improved properties.

Particularly preferred is diversification of one or more amino acid residues in LCDR3 of VL, HCDR3 of VH, LCDR1 of VL and/or HCDR2 of VH. Diversification can be done by synthesizing a collection of DNA molecules using trinucleotide mutagenesis (TRIM) technology [Virnekas, 8., Ge, L., PIUckthun, A., Schneider, K.C., Wellnhofer, G., and Moroney SE. (1994) Trinucleotide phosphoramidites: ideal ts for the sis of mixed oligonucleotides for random mutagenesis. Nucl. Acids Res. 22, 5600; see also Example 8].

Conservative Amino Acid Variants Polypeptide variants may be made that conserve the overall molecular structure of an antibody peptide sequence described herein. Given the properties of the individual amino acids, some rational substitutions will be recognized by the skilled worker.

Amino acid substitutions, i.e., "conservative substitutions," may be made, for ce, on the basis of similarity in polarity, charge, solubility, hydrophobicity, hilicity, and/or the amphipathic nature of the residues involved.

For example, (a) nonpolar (hydrophobic) amino acids include alanine, leucine, isoleucine, valine, proline, alanine, tryptophan, and methionine; (b) polar neutral amino acids include glycine, , threonine, cysteine, tyrosine, asparagine, and glutamine; (c) positively charged (basic) amino acids e arginine, lysine, and ine; and (d) negatively d (acidic) amino acids include aspartic acid and glutamic acid. Substitutions typically may be made within groups ). In addition, glycine and e may be substituted for one another based on their ability to disrupt o-helices. Similarly, certain amino acids, such as alanine, cysteine, leucine, methionine, glutamic acid, glutamine, histidine and lysine are more commonly found in o-helices, while valine, isoleucine, phenylalanine, tyrosine, tryptophan and threonine are more commonly found in B—pleated sheets. Glycine, serine, aspartic acid, asparagine, and proline are commonly found in turns. Some preferred substitutions may be made among the following groups: (i) S and T; (ii) P and G; and (iii) A, V, L and I. Given the known genetic code, and recombinant and synthetic DNA techniques, the skilled scientist readily can construct DNAs encoding the conservative amino acid As used herein, "sequence identity" between two polypeptide sequences, indicates the percentage of amino acids that are identical between the sequences. "Sequence homology" indicates the percentage of amino acids that either are identical or that ent conservative amino acid substitutions. red polypeptide sequences of 1O the ion contain amino acid sequences, y a. the amino acid sequence of the HCDR1 is identical to SEQ ID NO: 5 in at least 7 of 8 amino acids, and b. the amino acid sequence of the HCDR2 is identical to SEQ ID NO: 6 in at least 14 of 19, more preferred 15 of 19, more preferred 16 of 19, more preferred 17 of 19, or even more preferred 18 of 19 amino acids, and c. the amino acid sequence of the HCDR3 is identical to SEQ ID NO: 7 in at least 8 of 11, more preferred 9 of 11, or even more preferred 10 of 11 amino acids, and d. the amino acid sequence of the LCDR1 is identical to SEQ ID NO: 8 in at least 12 of 14, or more preferred 13 of 14 amino acids, and e. the amino acid sequence of the LCDRZ is identical to SEQ ID NO: 9 in at least 4 of 7, more preferred 5 of 7, or even more red 6 of 7 amino acids, and f. the amino acid sequence of the LCR3 is identical to SEQ ID NO: 10 in at least 11 of 12 amino acids.

DNA molecules of the invention The present invention also relates to the DNA molecules that encode an antibody of the invention. These sequences include, but are not limited to, those DNA molecules set forth in SEQ ID NOs 3 and 4.

DNA molecules of the invention are not limited to the sequences disclosed herein, but also include ts thereof. DNA ts within the invention may be described by reference to their physical properties in hybridization. The skilled worker will recognize that DNA can be used to identify its ment and, since DNA is double stranded, its equivalent or g, using nucleic acid hybridization techniques. It also will be recognized that hybridization can occur with less than 100% complementarity.

WO 63932 However, given riate choice of conditions, hybridization techniques can be used to differentiate among DNA sequences based on their structural relatedness to a particular probe. For guidance regarding such conditions see, Sambrook et al., 1989 [Sambrook, J., Fritsch, E. F. and Maniatis, T. (1989) lar Cloning: A laboratory manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, USA)] and Ausubel et al., 1995 [Ausubel, F. M., Brent, R., Kingston, R. E., Moore, D. D., Sedman, J. G., Smith, J. A., & Struhl, K. eds. (1995). Current Protocols in Molecular Biology. New York: John Wiley and Sons].

Structural similarity n two polynucleotide sequences can be expressed as a 1O function of "stringency" of the conditions under which the two sequences will hybridize with one another. As used herein, the term "stringency" refers to the extent that the conditions disfavor hybridization. Stringent conditions strongly disfavor hybridization, and only the most structurally related molecules will hybridize to one another under such conditions. Conversely, non-stringent conditions favor ization of molecules displaying a lesser degree of structural relatedness. Hybridization ency, therefore, directly correlates with the structural relationships of two nucleic acid sequences. The following relationships are useful in correlating hybridization and relatedness (where Tm is the melting temperature of a nucleic acid ): a. Tm = 69.3 + O.41(G+C)% b. The Tm of a duplex DNA decreases by 1°C with every increase of 1% in the number of mismatched base pairs.

C. (Tm)p2' (Tm)p1 = 18.5 lOg10H2/H1 where p1 and u2 are the ionic strengths of two solutions. ization stringency is a function of many factors, including overall DNA concentration, ionic strength, temperature, probe size and the ce of agents which disrupt en g. Factors promoting hybridization include high DNA 3O concentrations, high ionic strengths, low temperatures, longer probe size and the absence of agents that disrupt hydrogen bonding. ization typically is performed in two phases: the “binding” phase and the “washing” phase.

First, in the binding phase, the probe is bound to the target under conditions favoring hybridization. Stringency is y controlled at this stage by altering the temperature.

For high stringency, the temperature is usually between 65°C and 70°C, unless short (< 2012/060078 nt) oligonucleotide probes are used. A entative ization solution comprises 6x SSC, 0.5% SDS, 5x Denhardt's solution and 100 pg of nonspecific carrier DNA [see Ausubel et al., section 2.9, supplement 27 (1994)]. Of course, many different, yet functionally equivalent, buffer conditions are known. Where the degree of relatedness is lower, a lower temperature may be . Low stringency binding temperatures are between about 25°C and 40°C. Medium stringency is between at least about 40°C to less than about 65°C. High stringency is at least about 65°C.

Second, the excess probe is removed by washing. It is at this phase that more stringent ions usually are applied. Hence, it is this "washing" stage that is most important in ining dness via hybridization. Washing solutions typically n lower salt concentrations. One exemplary medium stringency solution contains 2x SSC and 0.1% SDS. A high stringency wash solution ns the equivalent (in ionic strength) of less than about 0.2x SSC, with a preferred stringent solution containing about 0.1x SSC. The temperatures associated with various stringencies are the same as discussed above for "binding." The washing solution also lly is replaced a number of times during washing. For e, typical high stringency washing conditions comprise washing twice for 30 minutes at 55° C and three times for minutes at 60° C.

Accordingly, subject of the present invention is an isolated nucleic acid sequence that encodes the antibody and antigen-binding fragments of the present invention.

Another embodiment of the present invention is the aforementioned isolated nucleic acid sequence, which encodes the dies of the present invention, whereby the nucleic acid sequences are as given in table 5.

Accordingly, the present invention includes nucleic acid molecules that hybridize to the molecules of set forth in Table 5 under high stringency g and washing conditions, where such nucleic molecules encode an antibody or functional fragment thereof having properties as described herein. Preferred molecules (from an mRNA perspective) are those that have at least 75% or 80% (preferably at least 85%, more preferably at least 90% and most preferably at least 95%) sequence identity with one of the DNA molecules described herein. The molecules block prolactin receptor mediated signalling.

Functionally Eguivalent Variants Yet another class of DNA variants within the scope of the invention may be described with reference to the product they encode. These functionally equivalent genes are characterized by the fact that they encode the same peptide sequences found in SEQ ID No: 1 and 2 due to the degeneracy of the genetic code.

It is recognized that variants of DNA molecules provided herein can be constructed in several ent ways. For example, they may be ucted as completely synthetic DNAs. Methods of efficiently synthesizing oligonucleotides in the range of 20 to about 1O 150 nucleotides are widely available. See Ausubel at al., section 2.11, Supplement 21 (1993). Overlapping ucleotides may be sized and assembled in a fashion first reported by Khorana et a/., J. Mol. Biol. 72:209-217 (1971); see also Ausubel et al., supra, Section 8.2. Synthetic DNAs preferably are designed with ient restriction sites engineered at the 5' and 3‘ ends of the gene to facilitate cloning into an appropriate vector.

As indicated, a method of generating variants is to start with one of the DNAs disclosed herein and then to conduct site-directed mutagenesis. See Ausubel et al., supra, r 8, Supplement 37 (1997). In a typical method, a target DNA is cloned into a single-stranded DNA bacteriophage vehicle. Single-stranded DNA is isolated and hybridized with an oligonucleotide containing the desired nucleotide alteration(s). The complementary strand is synthesized and the double stranded phage is introduced into a host. Some of the resulting y will contain the desired mutant, which can be confirmed using DNA sequencing. In addition, various methods are available that increase the probability that the progeny phage will be the d mutant. These methods are well known to those in the field and kits are commercially available for generating such mutants.

Recombinant DNA constructs and expression The present invention r provides recombinant DNA constructs comprising one or more of the nucleotide sequences of the present invention. The inant constructs of the present invention are used in connection with a vector, such as a plasmid, phagemid, phage or viral , into which a DNA molecule ng an antibody of the ion is inserted.

The encoded gene may be ed by techniques described in Sambrook et a/., 1989, and Ausubel et al., 1989. Alternatively, the DNA sequences may be chemically synthesized using, for example, synthesizers. See, for e, the techniques described in OLIGONUCLEOTIDE SYNTHESIS (1984, Gait, ed., IRL Press, ), which is incorporated by reference herein in its entirety. The expert in the field is able to fuse DNA encoding the variable domains with gene fragments encoding constant regions of various human IgG isotypes or derivatives thereof, either mutated or non-mutated. He is able to apply recombinant DNA technology in order to fuse both variable s in a single chain format using linkers such as a fifteen-amino acid stretch containing three times glycine-glycine-glycine—glycine-serine. Recombinant constructs of the invention are comprised with expression vectors that are capable of expressing the RNA and/or protein products of the encoded DNA(s). The vector may further comprise regulatory sequences, including a promoter ly linked to the open reading frame (ORF). The vector may r comprise a selectable marker ce. ic initiation and bacterial secretory signals also may be required for efficient ation of inserted target gene coding sequences.

The present invention further es host cells containing at least one of the DNAs of the present ion. The host cell can be virtually any cell for which expression vectors are available. It may be, for example, a higher eukaryotic host cell, such as a mammalian cell, a lower eukaryotic host cell, such as a yeast cell, and may be a prokaryotic cell, such as a bacterial cell. Introduction of the recombinant uct into the host cell can be effected by calcium phosphate transfection, DEAE, dextran mediated transfection, electroporation or phage infection. ial Expression Useful expression vectors for bacterial use are constructed by inserting a structural DNA sequence ng a desired protein together with suitable translation initiation and termination signals in operable reading phase with a functional promoter. The vector will comprise one or more phenotypic selectable s and an origin of replication to ensure maintenance of the vector and, if desirable, to provide amplification within the host. Suitable prokaryotic hosts for transformation e E. coli, Bacillus is, ella typhimurium and various species within the genera Pseudomonas, Streptomyces, and Staphylococcus.

Bacterial vectors may be, for example, bacteriophage, plasmid- or phagemid-based.

These vectors can contain a selectable marker and bacterial origin of replication derived from commercially available plasmids typically containing elements of the well known cloning vector pBR322 (ATCC 37017). Following transformation of a suitable host strain and growth of the host strain to an appropriate cell density, the selected promoter is de-repressedlinduced by appropriate means (e.g., temperature shift or chemical induction) and cells are cultured for an additional period. Cells are typically harvested by centrifugation, disrupted by physical or chemical means, and the resulting crude t retained for further cation.

In bacterial systems, a number of sion vectors may be advantageously ed depending upon the use intended for the protein being expressed. For e, when a large quantity of such a protein is to be produced, for the generation of antibodies or to screen peptide libraries, for example, vectors which direct the expression of high levels of fusion protein products that are readily purified may be desirable.

Therefore an object of the present invention is an expression vector comprising a 1O nucleic acid sequence encoding for the novel antibodies of the present invention.

Mammalian Expression & Purification red tory sequences for mammalian host cell expression include viral elements that direct high levels of protein expression in mammalian cells, such as promoters and/or enhancers derived from cytomegalovirus (CMV) (such as the CMV promoter/enhancer), Simian Virus 40 (SV40) (such as the SV40 er/enhancer), adenovirus, (e.g., the adenovirus major late promoter (AdMLP)) and polyoma. For further description of viral regulatory elements, and sequences thereof, see e.g., U.S. ,168,062 by Stinski, U.S. 4,510,245 by Bell et al. and U.S. 4,968,615 by Schaffner et al. The recombinant expression vectors can also include origins of replication and selectable markers (see e.g., U.S. 4,399,216, 4,634,665 and U.S. 5,179,017, by Axel et al.). Suitable able markers include genes that confer resistance to drugs such as G418, hygromycin or methotrexate, on a host cell into which the vector has been introduced. For e, the dihydrofolate reductase (DHFR) gene confers resistance to methotrexate and the neo gene confers resistance to G418.

Transfection of the expression vector into a host cell can be d out using standard techniques such as electroporation, m-phosphate precipitation, and DEAE- dextran transfection.

Suitable mammalian host cells for expressing the dies, antigen binding portions, or derivatives thereof provided herein include Chinese Hamster Ovary (CHO cells) [including dhfr— CHO cells, described in Urlaub and Chasin, (1980) Proc. Natl. Acad.

Sci. USA 77:4216-4220, used with a DHFR selectable marker, e.g., as described in R.

J. Kaufman and P. A. Sharp (1982) Mol. Biol. 1-621]], NSO myeloma cells, COS cells and SP2 cells. In some embodiments, the expression vector is designed such that the sed protein is secreted into the culture medium in which the host cells are grown. The antibodies, antigen binding portions, or derivatives thereof can be recovered from the culture medium using rd protein purification methods.

Antibodies of the invention or an antigen-binding fragment thereof can be recovered and purified from recombinant cell cultures by well-known methods including, but not limited to ammonium sulfate or ethanol precipitation, acid extraction, n A chromatography, n G chromatography, anion or cation exchange chromatography, phospho-cellulose chromatography, hobic interaction chromatography, affinity chromatography, hydroxylapatite chromatography and lectin chromatography. High performance liquid chromatography ”) can also be 1O ed for purification. See, e.g., Colligan, Current ols in Immunology, or Current Protocols in Protein e, John Wiley & Sons, NY, N.Y., (1997-2001), e.g., Chapters 1, 4, 6, 8, 9, 10, each ly incorporated herein by reference.

Antibodies of the present invention or antigen-binding fragment thereof include naturally purified products, products of chemical synthetic procedures, and products produced by inant techniques from a eukaryotic host, including, for example, yeast, higher plant, insect and mammalian cells. Depending upon the host employed in a recombinant production procedure, the antibody of the present invention can be glycosylated or can be non-glycosylated. Such methods are described in many rd laboratory manuals, such as Sambrook, supra, Sections 17.37-17.42; Ausubel, supra, Chapters 10, 12, 13, 16, 18 and 20.

Therefore an object of the present invention are also host cells comprising the vector or a nucleic acid molecule, whereby the host cell can be a higher eukaryotic host cell, such as a mammalian cell, a lower eukaryotic host cell, such as a yeast cell, and may be a prokaryotic cell, such as a ial cell.

Another object of the present invention is a method of using the host cell to produce an antibody and antigen binding fragments, comprising culturing the host cell under suitable conditions and recovering said antibody.

Therefore another object of the present invention is the dy as described in the present invention produced with the host cells of the present invention and purified to at least 95% homogeneity by weight.

Endometriosis and adenomyosis (endometriosis interna) Endometriosis is a benign, estrogen-dependent, gynecological er that is characterized by the presence of endometrial tissue (glands and stroma) outside the uterine cavity. Endometriotic lesions are mainly found on the pelvic peritoneum, in the ovaries and the rectovaginal septum (Obstet. Gynecol. Clin. North. Am. -238, 1997). Endometriosis is often associated with infertility and pain symptoms such as dysmenorrhoea. In addition, many patients suffer from autoimmune diseases (Hum.

Reprod. 17(19):2715-2724, 2002). Adenomyosis uteri also known as endometriosis interna bes a subform of endometriosis which is restricted to the uterus. In case of 1O adenomyosis uteri, endometrial glands invade the rium and the uterine wall.

According to the transplantation , endometrial fragments are flushed by retrograde menstruation into the peritoneal cavity in both, patients and healthy women (Obstet. Gynecol. 64:151-154, 1984). Four main s seem to be critically ed in the successful establishment of endometriotic lesions in the pelvic cavity of patients: a) In the late secretory phase of the menstrual cycle, endometrial cells in healthy women become apoptotic. In patients, the extent of apoptosis in trial cells is clearly reduced (Fertil. Steril. 69:1042-1047,1998). ore, in patients there is a higher probability than in healthy women, that endometrial fragments that have been flushed into the peritoneal cavity by retrograde menstruation do not die and t successfully. b) For successful implantation in the peritoneum and long-term survival of the c endometrial fragments, new blood vessels have to form (British Journal of Pharmacology, 149:133-135, 2006). 0) Many patients suffer from mune disease and thus have a compromised immune system (Hum. Reprod. 17(19): 2002, 2715-2724, 2002). This may lead to the conclusion that an intact immune se — as it is present in healthy women — may play a role for the prevention of the establishment of endometriotic lesions. d) Lesions have to grow and thus depend on the presence of mitogenic stimuli and growth factors.

For the treatment of endometriosis, the following approaches exist currently: a) Gonadotropin-releasing hormone (GnRH) analogues: lead to ssion of ovarian estradiol synthesis and induce atrophy of ectopic endometriotic implants that depend critically on the presence of iol for growth. b) Aromatase inhibitors: inhibit the local production of estradiol by endometriotic implants, induce sis and inhibit proliferation of ectopic endometriotic fragments. c) Selective estrogen receptor modulators: have estrogen receptor antagonistic activity in normal endometrial and ectopic implants and thus lead to atrophy of implanted ectopic endometriotic . d) Progesterone receptor agonists: inhibit proliferation of normal and ectopic trial cells, induce entiation and apoptosis. e) Combined oral contraceptives: maintain the status quo, prevent progression of 1O the e, and induce atrophy of the ectopic and eutopic endometrium. f) Surgical excision of lesions.

GnRH analogues, SERMs, and aromatase inhibitors have severe side s and lead to hot flushes and bone loss in young women suffering from endometriosis. Treatment with terone receptor agonists leads to ovulation inhibition, irregular menstrual bleeding followed by amenorrhoea, body weight gain and sion. Due to increased risk for venous thrombembolism, combined oral contraceptives are not indicated in women older than 35 years, smokers and individuals suffering from overweight.

Surgical excision of lesions is prone to high recurrence rates.

The dy of the present ion interferes with PRLR-mediated signalling stimulated by pituitary- and locally-produced prolactin or due to activating PRLR mutations and are therefore more effective than dopamine-2— receptor agonists which interfere only with ary prolactin secretion.

Therefore an object of the present invention is the antibody or antigen-binding fragments as described in the present invention as a medicament.

PRL and the PRLR are expressed in the uterus and play a role in normal uterine physiology; PRL can act as a potent mitogen and has an modulatory role. In the present invention it is shown that alterations in the PRL/PRLR system play a role in human triosis. An analysis of the expression of PRL and the PRLR in endometrium of healthy women and in endometrium and lesions of patients (see Example 4) by quantitative Taqman PCR is shown in Figures 1 and 2.

As demonstrated in Figure 1 (PRL expression) and Figure 2 (PRLR expression), both PRL and its receptor are strongly upregulated in endometriotic lesions. These findings are surprising and in sharp contrast to a previously published study (Acta Obstet Gynecol Scand 81:5-10, 2002) which describe almost te absence of PRLR expression in human endometriotic lesions.

The findings of the present invention generate for the first time experimental evidence that autocrine PRL signalling plays a fundamental role in the establishment, growth, and maintenance of triotic lesions.

The PRLR dy Mat3 was successfully tested in an animal model of endometriosis a, i.e. adenomyosis uteri in mice (see Example 5). Adenomyosis is characterized by infiltrative growth of endometrial glands in the myometrial layer of the endometrium.

It resembles an endometriosis form restricted to the uterus - the only form of 1O endometriosis non-menstruating s can develop.

Danazol which is effective in the clinical treatment of patients suffering from endometriosis is also effective in the treatment of adenomyosis uteri (Life Sciences 51:1119-1125, 1992). However danazol is an androgenic progestin and leads to severe androgenic side-effects in young women, which limits its use.

The antibody of the present invention solves the problem for providing new ents or prevention for endometriosis and exhibit lesser side effects than current standard therapies. r aspect of the present invention is the use of the dy Mat3 and n binding fragments as described in the present invention for the treatment or prevention of endometriosis and adenomyosis (endometriosis interna).

Benign breast disease and mastalgia Benign breast disease encompasses a variety of ms, such as fibrocystic breast disease, fibroadenoma, mastalgia, and macrocysts. 30 — 50% of premenopausal women suffer from fibrocystic breast disease (Epidemiol Rev 19:310-327, 1997).

Depending on the women’s age, benign breast disease can present with distinct phenotypes (J Mammary Gland Biol Neoplasia 10: 325-335, 2005): during the early reproductive phases (15 — 25 years) when lobular pment in the normal breast takes place, benign breast disease s in fibroadenomas. Single giant 1O fibroadenomas as well as multiple adenomas are observed. These fibroadenomas are composed of stromal as well as epithelial cells and arise from lobules. In the mature uctive phase (25 — 40 years) the breast is t to cyclical changes during each menstrual cycle. Diseased women present with cyclical mastalgia and several nodules in their breast. Later (35 - 55 years of age), the normal breast tes whereas in the diseased breast macrocysts and epithelial hyperplasia with and without atypia can be observed. Those forms of benign breast e that are accompanied by enhanced epithelial cell proliferation have a higher risk for developing mammary carcinomas. This risk can be up to 11% if ar atypias are present in the proliferating cell on (Zentralbl Gynakol 119: 54-58, 1997). 25 % of women aged 60 — 80 years also suffer from benign breast disease, often en replacement y or adiposity are the reasons for persisting benign breast disease after menopause (Am J Obstet Gynecol 154: 161-179, 1986).

The pathophysiology of fibrocystic breast disease is determined by en predominance and progesterone deficiency that results in roliferation of connective tissues (fibrosis) which is followed by facultative epithelial cell proliferation.

As already mentioned, the risk of breast cancer is elevated in patients exhibiting enhanced epithelial cell proliferation within the fibrocystic foci. Clinically fibrocystic breast disease presents with breast pain and breast tenderness. 7O % of the patients 3O with fibrocystic breast disease suffer from either corpus luteum insufficiency or anovulation (Am J Obstet 154: 161-179, 1986). Corpus luteum insufficiency results in reduced progesterone levels and estrogen predominance.

Mastalgia (breast pain) affects about 70 % of women at some time in their reproductive lifespan. Breast pain may or may not be associated with other criteria of the premenstrual syndrome. It has been demonstrated that women suffering from mastalgia respond with an excess tin release after stimulation of the hypothalamic pituitary axis (Clin Endocrinol 23: 699-704, 1985).

Standard therapies of benign breast disease and mastalgia are: 1) Bromocriptine Bromocriptine as a n t blocks only ary prolactin synthesis, but not local synthesis of prolactin in the mammary epithelial cells. It is therefore only effective in those forms of mastalgia and benign breast disease that rely on elevated systemic prolactin levels. Major side effects of bromocriptine are: 1O Nausea, vomiting, edema, hypotension, dizziness, hair loss, headache, and halluzinations 2) Danazol Danazol is an androgenic progestin that via its antigonadotrophic activity counteracts the estrogen predominance observed in benign breast disease. Major side effects are: Menstrual irregularities, depression, acne, hirsutism, voice deepening, and hot flushes as well as weight gain. 3) Tamoxifen Tamoxifen is a selective estrogen receptor tor with antiestrogenic activity in the breast and estrogenic activity in the uterus. Major side effects are: postmenopausal symptoms such as bone loss and hot flushes, ovarial cysts, and endometrial oma. 4) Progestins Progestins inhibit benign breast disease via suppression of the pituitary gonadal axis, ion inhibition and estrogen depletion. Estrogen depletion leads to menopausal symptoms such as bone loss and hot s. 5) Low dose combined oral contraceptives This treatment is not ted in women older than 35 years of age, smoking as well as diabetic and ight patients.

In general, prolactin levels have been found to be increased in one third of women with benign breast disease. Since estrogens enhance pituitary prolactin secretion, the increase in serum tin levels has been thought to be a consequence of the predominance of estrogens in this disease. It has been ed that an activating PRLR mutation is often present in women suffering from multiple breast adenomas — resembling a subtype of fibrocystic breast disease (Paul Kelly, Breast Congress Turin, 2007 and Proc Natl Acad Sci 105: 14533-14538; 2008).

Benign breast disease, mastalgia and premenstrual breast tension rely on one common pathophysiological mechanism: enhanced prolactin signalling. Elevated prolactin signalling can be the consequence of: - systemic hyperprolactinemia (due to pituitary adenoma) - local rolactinemia (due to tin synthesis in proliferating mammary 1O gland epithelial cells). Local hyperprolactinemia does not translate into elevated prolactin levels in the blood. - constitutively active PRLR signalling in the presence of normal prolactin levels (due to an activating PRLR mutation).

Given that certain forms of benign breast disease can give rise to breast cancer there is a medical need for the treatment of this disease.

To demonstrate the efficacy of lizing PRLR dy Mat3 in a preclinical model of benign breast disease, a mouse model based on systemic hyperprolactinemia was employed. Adult Balb/c mice were transplanted with pituitary fts under the kidney capsule as described in Example 6 (In: Methods in Mammary gland Biology and Breast Cancer Research, 7, 2000). In the mouse model of the t invention for benign breast disease, a ogen such as DMBA has not been used; the mice were only grafted with pituitary glands in order to study the consequence of Mat3 antibody application on enhanced benign epithelial cell proliferation. In a former study the pituitary-isografted animals were treated in addition with the carcinogen DMBA and the effects of a different monoclonal PRLR antibody on breast cancer development (Am J Pathol 133:589-595,1988) were analysed. These antibodies were effective in treating breast cancer, the effects on benign breast disease however were not analysed (Am J Pathol 133:589-595,1988).

In the model of the present invention, ic rolactinemia caused enhanced epithelial cell proliferation in the mammary gland, and stimulated sidebranching and Iobuloalveolar development in comparison to untreated virgin control mice. As described in Example 6, the neutralizing PRLR antibody Mat3 was tested in this Balb/c mouse model in comparison to an unspecific antibody with regard to its ability to: - block sidebranching and lobuloalveolar development - inhibit mammary epithelial cell eration - inhibit expression of the prolactin target gene elf5 The lizing PRLR antibody Mat3 inhibited sidebranching (Figure 3A) and expression of the prolactin target gene elf5 (Figure SB).

Another aspect of the present ion is the use of the antibody Mat3 and antigen binding fragments as described in the present invention for treatment of benign breast disease and mastalgia in pre- and postmenopausal women.

Other indications which benefit from the blockade of PRLR—mediated signalling by the antibody Mat3: Non-hormonal female contraception: Current approaches for female contraception are the following: a) Combined oral contraceptives containing ens and progestins.

The progestogenic component mediates the contraceptive effect via ve feedback on the hypothalamic-pituitary—gonadal axis. The estrogenic component tees a good bleeding control and iates the gestagenic action via 1O induction of the progesterone receptor in target cells. b) Intrauterine devices containing progestins only.

The locally ed progestin renders the endometrium in an implantation- resistant state. In addition, the cervical mucos becomes almost impermeable for sperm cells. c) Progestin only pills and implants.

The tin inhibits ovulation via negative feedback on the hypothalamic— pituitary-gonadal axis. In addition the permeability of the cervical mucus for sperm cells is d. d) Vaginal rings containing ethinylestradiol plus progestins The main side-effect of combined oral contraceptives is the elevated risk for venous thromboembolism (VTE). Moreover, overweight or smoking women, as well as women suffering from autoimmune diseases such as lupus and women older than 35 years cannot use oral combined contraceptives.

Intrauterine devices and implants containing progestins only can lead to dysfunctional uterine bleeding.

Progestin only pills can cause irregular bleeding patterns, spotting, amenorrhea. The risk for ectopic pregnancies increases. Weight gain and reductions in bone mass y are further side effects.

Vaginal rings can lead to vaginitis, rhea or expulsion.

PRLR-deficient mice have been generated a few years ago (Genes Dev 11:167-178, 1997). Interestingly, PRLR-deficient s, but not male mice, are completely sterile.

PRLR" females exhibited an arrest of egg development ately after fertilization, i.e. they showed an arrest of preimplantation development whereas ovulation was normal. Only very few oocytes d the blastocyst stage and were unable to implant in mutant females but developed to normal embryos in wildtype foster mothers after lantation. The infertility phenotype of PRLR-deficient mice could be rescued until m pregnancy by terone mentation. Obviously, PRLR-mediated signalling plays an important role in the maintenance and function of the corpus luteum producing progesterone that is necessary to allow and maintain pregnancy. In addition PRLR-deficient s, but not males, ted a reduction in body weight associated with a reduction in abdominal fat mass and leptin levels.

So far, no inactivating human PRLR mutation is known, therefore the precise role of PRLR-mediated signalling in human fertility is still unknown. However, there is 1O sing evidence that also in humans; a minimal prolactin level is required to allow for successful pregnancy. Patients suffering from primary infertility due to hyperprolactinemic corpus luteum insufficiency were treated with bromocriptin. In some cases, prolactin levels were oversuppressed and shortened luteal phases reappeared again (Bohnet HG et al. in Lisuride and other dopamine ts edited by BB. Calne et al, Raven Press, New York, 1983). From these data it was concluded that hyper- and hypoprolactinemic states interfere vely with female fertility. This can be explained by the interaction of PRL with its receptor. In case of low prolactin levels, there is no ient receptor activation, whereas in case of hyperprolactinemia, there is also no sufficient receptor activation, since all receptors are blocked by one prolactin molecule and cannot dimerize anymore. In other words, the dose response for prolactin is bell- shaped and l receptor activation is achieved only in a certain concentration range. There is evidence from a second study that lack of endometrial prolactin expression in patients leads to early implantation failure (Human Reprod. 19:1911- 1916, 2004). Moreover, it has been shown that ex vivo, prolactin can prevent apoptosis of cultured human granulosa cells and thus maintains early corpus luteum function as it has been demonstrated in PRLR-deficient mice (Human Reprod. 18:2672—2677,2003).

Compared to the aforementioned standard approaches, female contraception with lizing PRLR antibodies has several advantages: 0 the antibodies can be used in smoking, overweight, and older women as well as in women suffering from lupus erythematodes (PRLR antibodies might even be beneficial for the treatment of lupus and the reduction of abdominal fat, i.e. eficient mice had less abdominal fat). 0 the PRLR antibodies do not elevate the VTE (venous thrombembolic) risk 0 in contrast to estrogens and progestins used in combined oral contraception, neutralization of PRLR-mediated signalling leads to inhibition of breast epithelial proliferation and in contrast to al approaches for fertility l might even protect users from breast cancer.

Another object of the present invention is the use of the antibody Mat3 for female contraception with reduced side effects compared to standard treatments.

Lactation inhibition Prolactin is the main hormone involved in lactation after child birth. This is evidenced by the phenotype of PRLR—deficient mice. Even heterozygous mice have severe lactational 1O problems and are completely unable to nurse their offspring (Frontiers in Neuroendocrinology 22:140-145, 2001 ).

For many reasons, women have to stop breast feeding, i.e. al intake of drugs potentially dangerous to the infant, s infections (mastitis, nephritis), profuse postpartum hemorrhage, and severe maternal diseases such as diabetes, carcinoma, and debility or diseases of the newborn. Currently, dopamine or agonists such as bromocriptine and lisuride are used to inhibit lactation after child birth. However, these compounds can provoke severe side effects such as nausea, ng, edema, hypotension, dizziness, hair loss, headache, and halluzinations. In addition dopamine receptor agonists are not indicated in women suffering from cardiovascular disease and hypertension. A further disadvantage of bromocriptine is its short half life time requiring drug intake 4-6 times daily over a period of 14 days.

Therefore, we expect that neutralising DRLR antibodies are suitable for lactation inhibition. In a former publication an antiserum generated against partly purified PRLR was given to lactating rats. It was speculated that the rum led to lactation tion since there was a small decrease in litter weight (Endocrinology 10221657- 1661,1978). However the authors were not able to exclude that even other mechanisms might have led to the slight reduction in litter weight. In addition they observed that the antiserum caused an increase in corpora lutea in treated rats ((Endocrinology 102:1657-1661,1978). This observation is in clear contrast to the ype of PRLR- 3O deficient mice s Dev 11:167-178, 1997) in which ion was unimpaired and in which no increase in corpora lutea was observed. Most likely the employed antiserum blocked some additional unknown molecules.

Another object of the t invention is the use of the dy Mat3 for inhibition of lactation.

Benign prostate hygerglasia Benign prostate lasia (BPH) is the fourth most prevalent healthcare ion in older men. Prostate enlargement is an age-dependent progressive condition that affects more than 50% of men aged 2 50 years of age. BPH is characterized by hyperplasia of prostatic stromal and lial cells, resulting in the formation of large discrete nodules in the periurethral region of the prostate which compresses the urethral canal. Thus, impairment of urine flow is one major consequence of BPH.

Standard therapies for BPH encompass: 1O a) a1-adrenergic or antagonists (e.g. tamsulosin, alfuzosin, terazosin, doxazosin) relief the BPH symptoms in the lower urinary tract. They decrease bladder outlet obstruction by blocking alpha-receptor—mediated stimulation of prostate smooth muscle. Major ffects are vasodilatory adverse events, dizziness and ejaculation failure. b) 5a—-reductase tors (e.g. finasteride) 5a—reductase inhibitors prevent the formation of dihydrotestosterone, the active form of testosterone in the prostate, which is responsible for the enlargement of the prostate. Major side-effects are sexual dysfunction, such as erectile disorders and decreased libido. 2O c) Transurethral resection of the prostate (TURP) This surgical treatment is associated with high morbidity. Side-effects are bleeding, incontinence, stricture formation, loss of ejaculation, and bladder perforation. d) te stenting A stent is ed into the prostatic part of the a to tee proper urine flow. Major side-effects are encrustation, urinary tract infection, and migration of the stent. er, stents have to be removed before any transurethral manipulation.

As described for the mammary gland, PRL and the PRLR act in an autocrine/paracrine way (J. Clin. Invest. 99:618 pp,1997) within the prostate.

Clinical s indicate that hyperprolactinemia (and agromegaly) is associated with prostatic enlargement and stromal accumulation of inflammatory cells. Human growth e can bind to the human PRLR in the presence of zinc which might explain why acromegaly can lead to benign prostate hyperplasia. PRL serum levels are often elevated in patients with BPH.

Transgenic animals pressing the PRL gene ubiquitously, develop severe stromal te hyperplasia, indicating PRL as an important hysiological factor for the development of prostate hyperplasia rinology 138:4410 pp,1997). Furthermore, local overexpression of PRL in enic mice under the te specific probasin promoter results in stromal expansion, lation of inflammatory cells and focal epithelial dysplasia which are basic characteristics of human BPH (Endocrinology 144:2269 pp,2003).

Another aspect of the present invention is the use of the antibody Mat3 or antigen- 1O binding fragments as described in the present invention for treatment of benign prostate hyperplasia.

Combined hormone therapy For the treatment of hot flushes in postmenopausal women still having a uterus, combinations of en (estradiol, or conjugated equine estrogens = CEE) and progestins (for example medroxyprogesterone acetate (MPA), progesterone, drospirenone, rgestrel) were used. Progestins have to be added to inhibit estradiol-activated uterine epithelial cell proliferation. However, addition of progestins increases mammary epithelial cell proliferation. Since both, normal as well as cancerous mammary epithelial cells d with proliferation towards combined estrogen plus progestin treatment, the relative risk of breast cancer was found to be increased after CEE plus MPA treatment (JAMA 233:321-333;2002).

The antibody of the present invention solves the m for treating enhanced breast lial cell proliferation observed under combined hormone therapy.

Another object of the present invention is the use of neutralizing PRLR antibody Mat3 or antigen-binding fragments in combined hormone therapy (i.e. estrogen + progestin therapy) to inhibit mammary epithelial cell proliferation.

Hair loss 3O Treatment of hair loss is still an unmet need. Scalp hair growth in cycles: the anagen phase is characterized by active hair growth; the catagen phase shows involution and is ed by the telogen phase (resting). The exogen phase (the release of the dead hair) coincides with the end of the telogen phase. Hair loss can be the consequence of disturbed hair growth in any phase.

Telogen hair loss can have many triggers (physiological and emotional stress, medical conditions, iron and zinc deficiency), antly androgenic alopecia in its early stages According to other aspects the present invention there is ed the use of an antibody or antigen binding fragment as described herein, in the manufacture of a medicament for the treatment or prevention of a disease or condition as discussed herein.

WO 63932 DEFINITIONS The target antigen human "PRLR" as used herein refers to a human polypeptide having substantially the same amino acid sequence in its extracellular domain as the amino acid positions 1 to 210 of SEQ ID NO. 12 and naturally occurring allelic and/or splice variants thereof. "ECD of PRLR" as used herein refers to the extracellular portion of PRLR represented by the aforementioned amino acids. In addition the target human PRLR also encompasses mutated versions of the receptor, such as the activating mutation |146L described by Paul Kelly (Proc Natl Acad Sci U S A105 (38): 14533- 1O 14538, 2008; and oral communication Turin, 2007).

The target antigen monkey "PRLR" as used herein refers to a rhesus as well as cynomolgus polypeptide having substantially the same amino acid sequence in its ellular domain as the amino acid positions 1 to 210 of SEQ ID NO. 11 and naturally occurring allelic and/or splice variants thereof. "ECD of PRLR" as used herein refers to the extracellular portion of PRLR represented by the aforementioned amino acids.

The target antigen murine or mouse "PRLR" as used herein refers to a murine polypeptide having ntially the same amino acid sequence in its extracellular domain as the amino acid positions 1 to 210 of SEQ ID NO. 13 and naturally occurring allelic and/or splice variants thereof. "ECD of PRLR" as used herein refers to the extracellular portion of PRLR represented by the aforementioned amino acids.

As used , the phrase "therapeutically effective amount" is meant to refer to an amount of therapeutic or prophylactic antibody that would be appropriate to elicit the desired therapeutic or prophylactic effect or response, including alleviating some or all of such symptoms of disease or reducing the predisposition to the disease, when administered in accordance with the desired treatment regimen.

As used herein, an antibody “binds ically to,” is “specific ” or fically recognizes” an antigen (here, PRLR) if such an antibody is able to discriminate n such antigen and one or more reference antigen(s), since binding icity is not an absolute, but a relative property. In its most l form (and when no defined reference is mentioned), “specific binding” is referring to the ability of the antibody to discriminate between the n of interest and an unrelated antigen, as determined, for example, in accordance with one of the following methods. Such methods comprise, but are not limited to Western blots, ELISA-, RIA—, ECL-, IRMA-tests and peptide scans.

For example, a standard ELISA assay can be carried out. The scoring may be carried out by standard color development (e.g. ary antibody with horseradish peroxide and ethyl benzidine with enperoxide). The reaction in certain wells is scored by the optical density, for example, at 450 nm. Typical background (=negative reaction) may be 0.1 OD; typical positive reaction may be 1 OD. This means the difference positive/negative can be more than 10-fold. Typically, determination of g icity is med by using not a single reference antigen, but a set of about three to five unrelated antigens, such as milk powder, BSA, transferrin or the like.

However, “specific binding” also may refer to the ability of an antibody to discriminate 1O between the target antigen and one or more closely related antigen(s), which are used as reference points. Additionally, fic binding” may relate to the ability of an antibody to discriminate between different parts of its target antigen, e.g. ent domains, subdomains or regions of PRLR, such as epitopes in the N-terminal or in the C-terminal region of the ECD of PRLR, or between one or more key amino acid residues or stretches of amino acid residues of the ECD of PRLR.

"Affinity" or "binding affinity" K0 are often determined by measurement of the equilibrium association constant (ka) and equilibrium dissociation nt (kd) and calculating the quotient of kd to ka (KD = kd/ka). The term "immunospecific" or "specifically binding" means, that the antibody binds to PRLR or its ECD with an affinity KB of lower than or equal to 10'5M (monovalent affinity). The term “high affinity” means, that the antibody binds to PRLR or its ECD with an affinity (KB) of lower than or equal to 10'7M (monovalent affinity). The antibody may have substantially greater affinity for the target antigen compared to other unrelated molecules. The antibody may also have substantially greater affinity for the target n compared to homologs, e.g. at least 1.5-fold, 2—fold, 5-fold d, 100-fold, 10'3-fold, 10'4-fold, 10'5-fold, 10'5-fold or greater relative ty for the target antigen. Such affinities may be readily determined using conventional techniques, such as by equilibrium dialysis; by using the BlAcore 2000 instrument, using general procedures outlined by the manufacturer; by 3O mmunoassay using radiolabeled target antigen; or by another method known to the skilled artisan. The affinity data may be analyzed, for example, by the method of Scatchard et al., Ann NY. Acad. ScL, 51: 660 (1949).

As used herein the phrase “antibodies nize tin mediated signalling” is meant to refer to a blockade of prolactin receptor activation by the antibodies of the present invention which leads to a complete inhibition of prolactin receptor mediated signalling.

As used herein the phrase odies compete for binding” is meant to refer to a competition between one antibody and a second ligand for binding to the prolactin receptor.

The term "antibody" is used in the broadest sense and includes fully assembled antibodies, monoclonal antibodies, polyclonal dies, multispecific dies (e.g., 1O ific antibodies), antibody fragments that can bind the antigen ( e.g., Fab', F‘(ab)2, Fv, single chain antibodies, diabodies), camel bodies and recombinant peptides comprising the forgoing as long as they exhibit the desired biological activity. Antibodies may carry ent constant domains (Fc s) on their heavy chain preferably derived from IgG1, IgGZ, or IgG4 isotypes (see below). Mutations for modification of effector functions may be introduced. Amino acid residues in the Fc-domain that play a dominant role in the interactions with the complement protein C1q and the Fc receptors have been identified and mutations influencing effector functions have been described (for a review see Labrijn et al., Current opinion in Immunology 20: 479-485, 2008).

Particularly, aglycosylation of IgG1 may be achieved by mutating asparagine to alanine or gine to glutamine at amino acid position 297, which has been reported to abolish antibody-derived cell-mediated cytotoxicity (ADCC) (Sazinsky et al., Proc. Nat.

Acad. Sci. 105 (51): 20169, 2008; Simmons et al., J. of Immunological Methods 263: 133—147, 2002). Replacement of lysine by alanine at position 322 leads to reduction of ADCC and removal of ment-derived cytotoxicity (CDC), while aneous replacement of the two leucines at on 234 and 235 by es leads to nce of ADCC and CDC [Hezareh et al., J. of Virology, 75 (24): 12161-12168, 2001]. In order to apply IgG4 isotypes as bivalent therapeutics in vivo which retain avidity, a modification such as the serine-to-proline exchange in the ‘core hinge region’ (Schuurman, J. et aI. Immunology 97: 8, 1999) may be introduced. The tendency of human IgG2 molecules to form heterogeneous covalent dimers may be circumvented by exchanging one of the cysteines at position 127, 232 and 233 to serine (Allen et al., Biochemistry, 2009, 48 (17), pp 3755—3766). An alternative format with reduced effector function may be the IgG2m4 format, derived from IgG2 carrying four IgG4-specific amino acid residue s (An et al., mAbs 1(6), 2009). Antibody fragments may be produced by recombinant DNA techniques or by enzymatic or chemical cleavage of intact dies and are described further below. Nonlimiting examples of onal antibodies include murine, chimeric, humanized, human, and Human EngineeredT'V' immunoglobulins, antibodies, chimeric fusion proteins having sequences derived from immunoglobulins, or s or derivatives thereof, each described further below. Multimers or aggregates of intact molecules and/or fragments, including chemically derivatized antibodies, are contemplated.

The term "monoclonal antibody" as used herein refers to an antibody obtained from a population of substantially homogeneous antibodies, i.e., the individual antibodies comprising the population are identical except for le naturally occurring mutations 1O that may be present in minor amounts. Monoclonal antibodies are highly specific, being directed against a single antigenic site. Furthermore, in st to conventional (polyclonal) antibody ations that typically include different antibodies directed against different determinants (epitopes), each monoclonal antibody is directed against a single determinant on the antigen. In addition to their specificity, the monoclonal antibodies are advantageous in that they are synthesized by the homogeneous culture, uncontaminated by other globulins with different specificities and characteristics.

The modifier "monoclonal" indicates the character of the antibody as being obtained from a substantially homogeneous population of antibodies, and is not to be construed as ing production of the antibody by any particular method. For e, the monoclonal antibodies to be used may be made by the hybridoma method first described by Kohler et al., , 256: 495 [1975, or may be made by recombinant DNA methods (see, e.g., U.S. Patent No. 4,816,567). The "monoclonal antibodies" may also be recombinant, chimeric, humanized, human, Human EngineeredT'V', or antibody nts, for example.

An "immunoglobulin" or "native antibody" is a tetrameric rotein. In a naturallyoccurring immunoglobulin, each tetramer is composed of two identical pairs of 3O polypeptide chains, each pair having one “light" (about 25 kDa) and one "heavy" chain (about 50—70 kDa). The amino-terminal portion of each chain includes a ble" region of about 100 to 110 or more amino acids primarily sible for antigen recognition. The carboxy- terminal portion of each chain s a nt region primarily responsible for effector function. lmmunoglobulins can be assigned to different classes depending on the amino acid sequence of the nt domain of their heavy chains. Heavy chains are classified as mu (p), delta (A), gamma (v), alpha (or), and epsilon (a), and define the antibody's isotype as lgM, lgD, lgG, lgA, and lgE, respectively. Several of these may be further divided into subclasses or isotypes, e.g. lgG1, lgG2, lgG3, lgG4, lgAl and lgA2. Different isotypes have different effector functions; for e, lgG1 and lgG3 isotypes often have ADCC activity. Human light chains are classified as kappa (K) and lambda (A) light chains. Within light and heavy chains, the le and constant regions are joined by a “J" region of about 12 or more amino acids, with the heavy chain also including a "D" region of about 10 more amino acids. See generally, Fundamental Immunology, Ch. 7 (Paul, W., ed., 2nd ed. Raven Press, NY. (1989)). 1O A “functional nt” or “antigen-binding antibody fragment” of an antibody/immunoglobulin hereby is defined as a fragment of an antibody/immunoglobulin (e.g., a le region of an lgG) that retains the n- binding region. An “antigen-binding region” of an antibody typically is found in one or more hypervariable region(s) of an antibody, i.e., the CDR-1, -2, and/or —3 regions; however, the le “framework” s can also play an important role in antigen binding, such as by providing a scaffold for the CDRs. Preferably, the “antigen-binding region” ses at least amino acid residues 4 to 103 of the variable light (VL) chain and 5 to 109 of the variable heavy (VH) chain, more preferably amino acid residues 3 to 107 of VL and 4 to 111 of VH, and particularly preferred are the complete VL and VH chains [amino acid positions 1 to 109 of VL and 1 to 113 of VH, while numbering of amino acid positions occurs according to the Kabat database (Johnson and Wu, c Acids Res, 2000, 28, 214-218)]. A preferred class of immunoglobulins for use in the present invention is lgG.

The term "hypervariable" region refers to the amino acid residues of the variable domains VH and VL of an antibody or functional fragment which are responsible for antigen-binding. The ariable region comprises amino acid residues from a "complementarity determining region" or CDR [i.e., residues 24-34 (LCDR1), 50 - 56 (LCDR2) and 88 - 97 (LCDR3) in the light chain variable domain and 29 - 36 (HCDR1), 3O 48 - 66 (HCDR2) and 93 - 102 (HCD \3) in the heavy chain le domain as described in Fig. 12] and/or those es from a hypervariable loop [i.e., residues 26 - 32 (within LCDR1), 50 - 52 (within LCDR2) and 91 - 96 (within LCDRB) in the light chain variable domain and 26 - 32 (within HCDR1), 53 - 55 (within HCDR2) and 96 - 101 (within HCDR3) in the heavy chain variable domain as described by Chothia et al., J.

Mol.Biol. 196: 901-917 (1987)].

Nonlimiting examples of antibody fragments e Fab, Fab', F(ab')2, Fv, domain antibody (dAb), complementarity determining region (CDR) fragments, single-chain antibodies (scFv), single chain antibody fragments, diabodies, triabodies, tetrabodies, minibodies, linear antibodies (Zapata et al., Protein Eng.,8 (10): 1057-1062 ); chelating recombinant dies, tribodies or bibodies, intrabodies, nanobodies, small modular immunopharmaceuticals (SMlPs), an antigen-binding-domain immunoglobulin fusion protein, a camelized antibody, a VHH containing antibody, or muteins or derivatives thereof, and polypeptides that contain at least a portion of an immunoglobulin that is sufficient to confer specific antigen g to the polypeptide, 1O such as a CDR sequence, as long as the antibody retains the desired biological activity; and multispecific antibodies formed from antibody fragments (C. A. K Borrebaeck, editor (1995) Antibody ering (Breakthroughs in Molecular Biology), Oxford University Press; R. Kontermann & S. Duebel, editors (2001) Antibody Engineering (Springer Laboratory ), Springer Verlag). An antibody other than a "bispecific" or "bifunctional" antibody is understood to have each of its binding sites identical. The F(ab’)2 or Fab may be engineered to minimize or completely remove the intermolecular disulphide interactions that occur between the CH1 and CL domains. Papain digestion of antibodies produces two identical antigen-binding fragments, called "Fab" fragments, each with a single antigen-binding site, and a residual "Fc" fragment, whose name reflects its ability to crystallize readily. Pepsin treatment yields an 2 fragment that has two “Fv” nts. An "Fv" fragment is the minimum antibody nt that contains a complete antigen ition and binding site. This region consists of a dimer of one heavy- and one light-chain variable domain in tight, non—covalent association. It is in this configuration that the three CDRs of each variable domain interact to define an antigen binding site on the surface of the VH-VL dimer.

Collectively, the six CDRs confer antigen-binding specificity to the antibody. However, even a single le domain (or half of an Fv comprising only three CDRs ic for an antigen) has the ability to recognize and bind antigen.

"Single-chain Fv" or "st" or "scFv" antibody fragments comprise the VH and VL domains of antibody, wherein these domains are t in a single polypeptide chain.

Preferably, the Fv ptide further ses a polypeptide linker between the VH and VL domains that enables the Fv to form the desired structure for antigen binding.

For a review of st see Pluckthun in The Pharmacology of Monoclonal Antibodies, vol. 113, Rosenburg and Moore eds., Springer-Verlag, New York, pp. 269-315 (1994).

The Fab fragment also contains the constant domain of the light chain and the first constant domain (CH1) of the heavy chain. Fab nts differ from Fab' fragments by the addition of a few residues at the carboxy terminus of the heavy chain CH1 domain including one or more cysteines from the antibody hinge region. Fab'-SH is the designation herein for Fab‘ in which the cysteine residue(s) of the constant domains bear a free thiol group. F(ab‘)2 antibody fragments originally were produced as pairs of Fab‘ fragments which have hinge cysteines between them. 1O “Framework" or FR residues are those variable domain residues other than the hypervariable region residues.

The phrase ant region" refers to the portion of the antibody molecule that confers effector functions.

The term "mutein“ or "variant" can be used interchangeably and refers to the polypeptide sequence of an antibody that ns at least one amino acid substitution, deletion, or ion in the variable region or the portion lent to the variable region, ed that the mutein or variant retains the desired binding affinity or biological activity.

Muteins may be ntially homologous or substantially identical to the parent antibody.

The term "derivative" refers to antibodies covalently modified by such ques as ubiquitination, conjugation to therapeutic or diagnostic agents, labeling (e.g., with radionuclides or various enzymes), covalent polymer attachment such as pegylation (derivatization with hylene glycol) and insertion or tution by chemical synthesis of non-natural amino acids.

A “human” antibody or functional human antibody fragment is hereby defined as one that is not chimeric or “humanized” and not from (either in whole or in part) a non- human species. A human antibody or functional antibody fragment can be derived from a human or can be a synthetic human antibody. A “synthetic human antibody” is defined herein as an antibody having a sequence derived, in whole or in part, in silico from tic sequences that are based on the analysis of known human antibody sequences. In silico design of a human antibody ce or fragment thereof can be achieved, for example, by ing a database of human antibody or antibody fragment sequences and devising a polypeptide sequence utilizing the data obtained therefrom. Another example of a human antibody or functional antibody fragment is one that is encoded by a nucleic acid ed from a library of antibody sequences of human origin (i.e., such library being based on antibodies taken from a human l source). Examples of human antibodies include n—CoDeR-based antibodies as described by Carlsson and deerlind Exp. Rev. Mol. Diagn. 1 (1), 102-108 (2001), n et al. Nat. Biotech. 18, 852-856 (2000) and U.S. Patent No. 6,989,250.

A “humanized antibody” or functional humanized antibody nt is defined herein as one that is (i) derived from a non-human source (e.g., a transgenic mouse which bears a heterologous immune system), which dy is based on a human germline sequence; or (ii) CDR-grafted, wherein the CDRs of the variable domain are from a non-human origin, while one or more frameworks of the variable domain are of human origin and the constant domain (if any) is of human origin.

The phrase "chimeric antibody," as used , refers to an antibody containing sequence derived from two different antibodies (see, e.g., U.S. Patent No. 4,816,567) which typically originate from different species. Most typically, chimeric antibodies comprise human and murine antibody fragments, generally human constant and mouse variable regions.

“Human EngineeredTM” antibodies generated by ng the parent sequence according to the methods set forth in cka et al., U.S. Patent No. 5,766,886 such as the antibody represented by SEQ ID N03 14 and 15 and bed in patent application W008/022295.

An antibody of the invention may be derived from a recombinant antibody gene library.

The development of logies for making repertoires of inant human antibody genes, and the display of the encoded antibody fragments on the surface of filamentous bacteriophage, has ed a recombinant means for directly making and selecting human antibodies, which also can be applied to zed, chimeric, murine or mutein antibodies. The antibodies produced by phage technology are produced as antigen binding fragments - usually Fv or Fab fragments - in bacteria and thus lack effector functions. Effector functions can be introduced by one of two strategies: The WO 63932 fragments can be engineered either into complete antibodies for expression in mammalian cells, or into bispecific antibody fragments with a second binding site capable of triggering an effector function. Typically, the Fd fragment (VH-CH1) and light chain (VL-CL) of antibodies are separately cloned by PCR and recombined randomly in combinatorial phage display libraries, which can then be selected for binding to a particular antigen. The Fab fragments are expressed on the phage surface, i.e., physically linked to the genes that encode them. Thus, selection of Fab by antigen binding co-selects for the Fab encoding sequences, which can be amplified subsequently. By several rounds of antigen binding and re-amplification, a ure 1O termed panning, Fab specific for the antigen are enriched and finally isolated.

A variety of procedures have been described for deriving human antibodies from phage- display libraries. Such libraries may be built on a single master ork, into which diverse in vivo-formed (i. e. human-derived) CDRs are allowed to recombine as bed by Carlsson and deerlind Exp. Rev. Mol. Diagn. 1 (1), 102-108 , Sb‘derlin et al. Nat. Biotech. 18, 852-856 (2000) and US. Patent No. 6,989,250.

Alternatively, such an antibody library may be based on amino acid sequences that have been designed in silica and encoded by nucleic acids that are synthetically d. In silica design of an antibody sequence is achieved, for example, by analyzing a database of human sequences and devising a polypeptide sequence ing the data ed therefrom. Methods for designing and ing in silica-created sequences are described, for example, in Knappik et al., J. Mol. Biol. (2000) 296:57; Krebs et al., J. l. s. (2001) 254:67; and US. Patent No. 064. For a review of phage y techniques, see W008/022295 (Novartis).

Alternatively, an antibody of this invention may come from animals. Such an antibody may be humanized or Human Engineered summarized in WOO8/022295 (Novartis); such an antibody may come from transgenic animals [see also WOO8/022295 (Novartis)].

As used herein, different ‘forms’ of antigen, e.g. PRLR, are hereby defined as different protein molecules resulting from different translational and posttranslational modifications, such as, but not d to, differences in splicing of the primary prolactin receptor transcript, differences in glycosylation, and differences in posttranslational proteolytic cleavage.

As used herein, the term ‘epitope’ includes any protein determinant capable of specific binding to an immunoglobulin or T-cell or. Epitopic determinants usually consist of chemically active surface groupings of molecules such as amino acids or sugar side chains and usually have specific three dimensional structural characteristics, as well as specific charge characteristics. Two antibodies are said to ‘bind the same epitope’ if one antibody is shown to compete with the second antibody in a competitive binding assay, by any of the methods well known to those of skill in the art, and all amino acids of the epitope are bound by the two antibodies. 1O The term ‘maturated dies’ or ‘maturated antigen-binding fragments’ such as maturated Fab ts includes derivatives of an antibody or antibody fragment exhibiting stronger binding - i. e. binding with increased affinity — to a given antigen such as the extracellular domain of the PRLR. Maturation is the process of identifying a small number of mutations within the six CDRs of an dy or dy fragment leading to this affinity increase. The maturation process is the combination of molecular biology methods for introduction of mutations into the antibody and screening for identifying the improved binders.

Therapeutic Methods Therapeutic methods involve administering to a subject in need of treatment a therapeutically effective amount of an antibody plated by the invention. A "therapeutically effective" amount hereby is defined as the amount of an dy that is of sufficient quantity to block eration of PRLR-positive cells in a treated area of a subject either as a single dose or according to a multiple dose regimen, alone or in combination with other agents, which leads to the ation of an e condition, yet which amount is toxicologically tolerable. The subject may be a human or non- human animal (e.g., rabbit, rat, mouse, monkey or other lower-order primate).

An antibody of the invention might be co-administered with known medicaments, and in some instances the antibody might itself be modified. For example, an dy could be conjugated to an immunotoxin or radioisotope to potentially further increase efficacy.

The inventive antibodies can be used as a eutic or a diagnostic tool in a variety of situations where PRLR is undesirably highly expressed. Disorders and conditions particularly suitable for ent with an antibody of the inventions are endometriosis, adenomyosis, non—hormonal female ity contraception, benign breast e and mastalgia, lactation tion, benign prostate hyperplasia, fibroids, hyper— and normoprolactinemic hair loss, and cotreatment in combined hormone therapy to inhibit y epithelial cell proliferation.

To treat any of the foregoing disorders, pharmaceutical compositions for use in accordance with the present invention may be formulated in a conventional manner using one or more physiologically acceptable carriers or excipients. An antibody of the invention can be administered by any suitable means, which can vary, depending on the type of disorder being treated. Possible stration routes include parenteral 1O (e.g., intramuscular, intravenous, intraarterial, intraperitoneal, or subcutaneous), intrapulmonary and intranasal, and, if desired for local suppressive treatment, intralesional administration. In addition, an antibody of the invention might be administered by pulse infusion, with, 9.9., ing doses of the antibody. Preferably, the dosing is given by injections, most preferably intravenous or subcutaneous ions, depending in part on r the administration is brief or chronic. The amount to be administered will depend on a variety of factors such as the clinical symptoms, weight of the individual, whether other drugs are administered. The skilled artisan will recognize that the route of administration will vary depending on the disorder or condition to be treated. ining a eutically effective amount of the novel polypeptide, according to this invention, y will depend on particular patient characteristics, route of administration, and the nature of the disorder being treated. General guidance can be found, for example, in the publications of the International Conference on Harmonisation and in REMINGTON'S PHARMACEUTICAL SCIENCES, rs 27 and 28, pp. 484-528 (18th ed., Alfonso R. Gennaro, Ed., Easton, Pa.: Mack Pub. Co., 1990).

More specifically, determining a therapeutically effective amount will depend on such factors as toxicity and efficacy of the medicament. Toxicity may be determined using methods well known in the art and found in the foregoing references. Efficacy may be determined utilizing the same guidance in conjunction with the methods described below in the Examples.

Pharmaceutical Compositions and Administration The present invention also relates to ceutical compositions which may comprise PRLR antibodies, alone or in combination with at least one other agent, such as stabilizing compound, which may be administered in any e, biocompatible pharmaceutical carrier, including, but not limited to, saline, buffered saline, dextrose, and water. Any of these molecules can be administered to a t alone, or in combination with other , drugs or hormones, in pharmaceutical compositions where it is mixed with excipient(s) or pharmaceutically acceptable carriers. In one 1O embodiment of the present ion, the pharmaceutically acceptable carrier is pharmaceutically inert.

The t invention also s to the administration of pharmaceutical compositions.

Such stration is accomplished parenterally. Methods of parenteral delivery include topical, intra-arterial (directly to the tumor), intramuscular, subcutaneous, intramedullary, intrathecal, entricular, intravenous, intraperitoneal, intrauterine or intranasal administration. In addition to the active ingredients, these pharmaceutical compositions may contain suitable pharmaceutically acceptable carriers comprising excipients and auxilliaries which facilitate processing of the active compounds into preparations which can be used pharmaceutically. Further details on techniques for formulation and administration may be found in the latest edition of ton's Pharmaceutical Sciences (Ed. Maack hing Co, Easton, Pa.).

Pharmaceutical formulations for parenteral administration include aqueous solutions of active compounds. For injection, the pharmaceutical compositions of the invention may be formulated in aqueous solutions, preferably in physiologically compatible s such as Hank's solution, Ringer's solution, or physiologically buffered saline. Aqueous injection sions may contain nces that increase viscosity of the suspension, such as sodium carboxymethyl ose, sorbitol, or dextran. Additionally, suspensions of the active compounds may be prepared as appropriate oily injection suspensions. Suitable lipophilic solvents or vehicles include fatty oils such as sesame oil, or synthetic fatty acid , such as ethyl oleate or triglycerides, or liposomes.

Optionally, the suspension may also contain suitable stabilizers or agents which increase the solubility of the compounds to allow for the preparation of highly concentrated solutions.

For l or nasal administration, penetrants appropriate to the particular barrier to be permeated are used in the ation. Such penetrants are generally known in the art.

The parenteral administration also comprises methods of parenteral delivery which also include intra-arterial, intramuscular, subcutaneous, intramedullary, hecal, and intraventricular, intravenous, intraperitoneal, intrauterine, vaginal, or asal administration. 1O Kits The invention further relates to pharmaceutical packs and kits sing one or more containers filled with one or more of the ingredients of the aforementioned compositions of the invention. Associated with such container(s) can be a notice in the form prescribed by a governmental agency regulating the manufacture, use or sale of pharmaceuticals or biological products, reflecting approval by the agency of the manufacture, use or sale of the product for human administration.

In another embodiment, the kits may contain DNA sequences encoding the dies of the invention. Preferably the DNA sequences encoding these antibodies are ed in a plasmid suitable for transfection into and expression by a host cell. The plasmid may contain a promoter (often an ble promoter) to regulate expression of the DNA in the host cell. The plasmid may also contain appropriate restriction sites to facilitate the insertion of other DNA sequences into the plasmid to produce various antibodies.

The plasmids may also contain numerous other elements to tate cloning and expression of the encoded proteins. Such elements are well known to those of skill in the art and e, for e, selectable markers, initiation codons, termination codons, and the like.

Manufacture and Storage The pharmaceutical compositions of the present invention may be manufactured in a manner that is known in the art, e.g., by means of conventional mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, ping or lyophilizing processes.

The pharmaceutical composition may be provided as a lyophilized powder in 1 mM-50 mM histidine, 0.1% - 2% sucrose, 2% — 7% mannitol at a pH range of 4.5 to 5.5 that is combined with buffer prior to use.

After pharmaceutical compositions comprising a compound of the invention formulated in an acceptable carrier have been prepared, they can be placed in an appropriate container and labeled for treatment of an indicated condition. For administration of PRLR antibodies, such labeling would include amount, frequency and method of 1O administration.

Therapeutically Effective Dose ceutical compositions suitable for use in the present invention include compositions wherein the active ingredients are contained in an effective amount to achieve the intended purpose, i.e. ent of a particular disease state characterized by PRLR expression. The determination of an effective dose is well within the capability of those skilled in the art.

For any compound, the therapeutically effective dose can be estimated initially either in cell culture assays, e.g., lymphoma cells, or in animal models, usually mice, rats, rabbits, dogs, pigs or monkeys. The animal model is also used to achieve a desirable concentration range and route of administration. Such information can then be used to determine useful doses and routes for stration in humans.

A therapeutically effective dose refers to that amount of protein or its antibodies, antagonists, or inhibitors that rate the symptoms or ion. Therapeutic efficacy and ty of such compounds can be determined by standard pharmaceutical procedures in cell cultures or experimental s, e.g., ED50 (the dose eutically effective in 50% of the population) and LD50 (the dose lethal to 50% of the population).

The dose ratio n therapeutic and toxic effects is the therapeutic index, and it can be sed as the ratio, EDso/LD50. Pharmaceutical compositions that exhibit large therapeutic indices are preferred. The data obtained from cell culture assays and animal s are used in formulating a range of dosage for human use. The dosage of such nds lies preferably within a range of circulating concentrations what include the EDso with little or no toxicity. The dosage varies within this range depending upon the dosage form employed, sensitivity of the patient, and the route of administration.

The exact dosage is chosen by the individual ian in view of the patient to be treated. Dosage and administration are adjusted to provide sufficient levels of the active moiety or to maintain the desired effect. Additional factors that may be taken into account include the ty of the disease state, eg, size and location of endometriotic lesions; age, weight and gender of the patient; diet, time and frequency of administration, drug combination(s), reaction sensitivities, and tolerance/response to 1O therapy. Long acting pharmaceutical compositions might be administered every 3 to 4 days, every week, or once every two weeks, or once within a month depending on half- life and clearance rate of the ularformulation.

Normal dosage amounts may vary from 0.1 to 100,000 micrograms, up to a total dose of about 2 g, depending upon the route of stration. ce as to particular dosages and methods of delivery is provided in the literature. See US. 4,657,760; US ,206,344; or US 5,225,212. Those skilled in the art will employ different formulations for polynucleotides than for proteins or their inhibitors. Similarly, delivery of polynucleotides or polypeptides will be ic to particular cells, conditions, locations, etc. Preferred specific activities for for a radiolabeled antibody may range from 0.1 to 10 mCi/mg of protein (Riva et al., Clin. Cancer Res. 5: 3280s, 1999; Wong et al., Clin. Cancer Res. 6: 3855-3863, 2000; Wagner et al., J. Nuclear Med. 43: 267—272, 2002).

The present invention is further bed by the following examples. The examples are provided solely to illustrate the ion by reference to specific embodiments. These exemplifications, while rating certain specific aspects of the invention, do not portray the tions or circumscribe the scope of the disclosed invention.

All examples were carried out using standard techniques, which are well known and routine to those of skill in the art, except where otherwise described in detail. Routine molecular biology techniques of the following examples can be carried out as described in rd laboratory manuals, such as Sambrook et al., Molecular g: A Laboratory Manual, 2nd Ed.; Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y., 1989.

DESCRIPTION OF THE FIGURES Figure 1: Expression of prolactin-mRNA (PRL—mRNA) (analyzed by real —time TaqMan PCR analysis) in human endometrium and lesions (ectopic tissue) from healthy women and women suffering from endometriosis.

Figure 2: Expression of prolactin receptor-mRNA (PRLR-mRNA) (analyzed by real—time TaqMan PCR analysis) in human endometrium and lesions (ectopic tissue) from healthy women and women suffering from endometriosis.

Figure 3A: Neutralizing prolactin or dy Mat3 inhibited sidebranching in y glands of mice which have been employed in a hyperprolactinemic surrogate model of benign breast disease. The unspecific antibody had no effect. Healthy normoprolactinemic mice (no pituitary) showed reduced anching, whereas pituitary transplantation (hyperprolactinemia) ed sidebranching and lobuloalveolar development. The specific antibody Mat3 antagonized the effects of hyperprolactinemia.

Figure SB: The neutralizing prolactin receptor dy Mat3 inhibited the induction of the prolactin target gene elf5 in mammary glands of mice in a hyperprolactinemic surrogate model of benign breast disease. The unspecific antibody had no effect.

Healthy, normoprolactinemic mice (no pituitary) showed reduced elf 5 expression in the mammary gland, whereas pituitary transplantation prolactinemia) strongly stimulated elf 5 gene expression. The specific antibody Mat3 but not the ific control antibody antagonized the effects of hyperprolactinemia.

Figure 4: Kabat Numbering of framework amino acid ons according to Johnson and Wu (Nucleic Acids Res. 2000, 28, 214-218).

Figure 5A: FACS analysis s with the anti-PRLR antibody HE06642. Binding of the antibody was determined at a fixed concentration on HEK293 cells expressing the human and mouse PRLR in comparison to the al cell line not expressing PRLR.

Y-axis: #, Median Fluorescence ity at 0.37 pg/ml HE06642 as lgG1 molecule. *, 1 = HEK293 with human PRLR; 2 = HEK293 with murine PRLR; 3 = HEK293 without PRLR.

Figure 58: FACS analysis results with the anti-PRLR antibody Mat3. Binding of the antibody was determined at a series of different concentrations on HEK293 cells expressing the human PRLR and Ba/F cells sing the rhesus PRLR in comparison to a cell line (HEK293) not expressing PRLR. Maximal signal intensities at highest antibody concentrations depend on the number of PRLRs expressed on the cell surfaces, i.e. HEK293 and Ba/F cells do not carry the same number of PRLRs on their surface. Y-axis: #, Median Fluorescence Intensity; X-axis: °, different concentrations in pg/ml of the antibody Mat3 as lgG2 molecule; *, 1 (circles) = HEK293 with human PRLR; 2 (triangles) = Ba/F with rhesus monkey PRLR; 3 (squares) = HEK293 without 1O PRLR.

Figure 6A: Alignment of the sequence region of the Mat3-VL domain with the most similar human V segment fied in VBASE2 (MatB-VL is 90% identical to germline sequence humlGLV056).

Figure GB: Alignment of the sequence region of the Mat3-VH domain with the most similar human V segment identified in VBASEZ (MatB—VH is 90% identical to germline sequence humlGHV313).

Figure 60: Alignment of the ce region of the 2-VL domain with the most similar human V segment identified in VBASEZ 42-VL is 80% identical to germline sequence humlGKV083).

Figure 6D: Alignment of the sequence region of the HEO6642—VH domain with the most similar human V segment identified in VBASEZ 42-VH is 89% identical to ne sequence humlGHV313).

Figure 7: ELISA-based binding tests of a maturated Fab variant: Fab-containing E coli supernatants were tested for binding to the lized extracellular domain of the human PRLR. The figure illustrates the binding of the Fab ts as a bar diagram. The signal intensities (extinction) are given on the y-axes (#), the names of the Fab variants (*) on the x-axes. Elevated signal intensity of the maturated Fab variant 00520-2 compared to the non-maturated Fab of the parental antibody 005-CO4 demonstrate better inding of 005—0042 compared to 005-004. The “variant” pET28 ents a supernatant of an E. coli strain carrying the Fab—expression plasmid pET28a (Novagen, EMD Chemicals Group, Merck, Darmstadt, y) which does not express any Fab.

Figure 8: Barplot representation of Pepscan ELISA results.

Each plotted value represents the average value obtained for 54 peptides with S.E.M (standard error of mean). The black bars represent the relative binding strength of antibody HE06642. The white bars represent the relative binding strength of antibody Mat3. The data was ized to average over the entire 2916 peptide dataset and corrected for ound signal.

Figure 8A shows the ELISA results for a subset of peptides ranging from amino acids 103-PDPPLELAVEVKQPE-117 indicated as ‘117’ on the X-axis to 127- IDLKTGWFT—141 (indicated as ‘141’). |. e. these peptides, which were shifted by three amino acids along the ECD amino acid ce, cover the region from amino acid on 103 to 141 of the ECD of human PRLR. The est differences observed within this dataset are for peptide 109-LAVEVKQPEDRKPYL-123 (indicated as ‘123’) with a significance p-value of 4x10”, and for peptide 121- PYLWlKWSPPTLIDL-135 (indicated as ‘135’) with a significance e of 7x104“.

Figure 8B shows the ELISA results for a subset of peptides ranging from 139- WFTLLYEIRLKPEKA—153 (indicated as ‘153’ on the X—axis) to 163- QQTEFKlLSLHPGQK-177 (indicated as ‘177’). |. e. these peptides, which were d by three amino acids along the ECD amino acid sequence, cover the region from amino acid position 139 to 177 of the ECD of human PRLR. The strongest differences observed within this dataset are for peptide 148-LKPEKAAEWEIHFAG-162 (indicated as ‘162’) with a significance p-value of 6x10"25, and for peptide 160- FAGQQTEFKILSLHP-174 (indicated as ‘174’) with a significance p-value of 8x108.

These data demonstrate that both dies bind to the 82 subdomain of the ECD of human PRLR (amino acid 101 to 210) and therefore are non-competitive to the natural ligand PRL which mainly binds to the 81 domain. However, this peptide scan showed that there are differences in binding to the 82 domains n Mat3 and HE06642.

This finding indicates why the antibody Mat3 shows a different species-specificity and potency compared to HE06642.

Figure 9: Inhibition of rolactin—induced ration of BaF3 cells monoclonal cells stably transfected with human prolactin receptor[ by liziflg tin receptor antibodies and unspecific control antibodies. The IC50 values were determined for the following antibodies in IgG1 format: Mat3 (closed circles), |Cso = 0.7 nM [100% inhibition at 1 pg/ml (= 6.7 nM)]; HE06.642 (open s), I050 = 4.2 nM [81% inhibition at 1 pg/ml (= 6.7 nM)]; unspecific control antibody (open triangles): no inhibitory effect.

Fi ure 10: Inhibition of rolactin-induced roliferation of BaF3 cells monoclonal cells stably transfected with the murine prolactin receptor) by neutralizing prolactin receptor antibodies and unspecific control antibodies. The IC50 values were determined for the following antibodies in IgG1 format: Mat3 (closed circles), I050 = 3.0 nM [97.4% inhibition at 1 ug/ml (= 6.7 nM)]; HE06.642 (open squares), no inhibitory effect; unspecific control antibody (open triangles): no tory .

Fi ure 11A and B: tion of rolactin-induced roliferation of BaF3 cells monoclonal cells stabl transfected with the rhesus rolactin rece tor b neutralizin rolactin receptor antibodies and unspecific control antibodies. The |C50 values were determined for the following antibodies in |gG1 format: Ivlat3 (closed circles), |Cso = 4.6 nM [99.1% inhibition at 1 pg/ml (= 6.7 nM)] (see Figure 11A); HE06.642 (open squares), IC50 = 206 nM [92.4% inhibition at 240 ug/ml (= 1600 nM)] (see Figure 11A and B); ific control dy (open triangles): no inhibitory effect (see Figure 11A and B).

Figure 12: Treatment of adenonlyosis uteri (= endometriosis interna) in SHN mice with neutralizing PRLR antibody MatB. The results are depicted on the y-axis as disease scores (adenomyosis scores) as described in e 5. The median disease score for each experimental group is indicated as a ntal bar. The mental groups are the following ones: group 1, no pituitary isograft (normoprolactinemic mice develop endometriosis interna to some degree, median disease score = 1); group 2, with pituitary isograft (hyperprolactinemia due to pituitary isografting es the disease score, median e score = 3); group 3, with pituitary isograft treated with unspecific murine IgGZa isotype control antibody once weekly at a dose of 30 mg/kg (median disease score = 3); group 4, with pituitary isograft treated with antibody Mat3 in the murine IgG2a format (Mat3-mlgGZa) once weekly at a dose of 30 mg/kg (Mat3 completely cured the animals. The disease score after 30 mg/kg Mat3 given once weekly was even lower (median disease score = 0) than the e score of normoprolactinemic mice (median disease score = 1); group 5, with pituitary isograft WO 63932 treated with antibody Mat3—mlgG2a once weekly at a dose of 10 mg/kg (median disease score = 2); group 6, with ary isograft treated with antibody Mat3-mlgGZa once weekly at a dose of 3 mg/kg (median disease score = 2.5); group 7, with pituitary isograft d with antibody Mat3-mlgGZa once weekly at a dose of 1 mg/kg n disease score = 2.5). Treatment with antibody Mat3 shows a dose-dependent decrease in the median disease score. Mat3 is therefore suitable to treat endometriosis interna (= adenomyosis uteri) and endometriosis externa in women.

Fifle 13A and B: Inhibition of luciferase reporter gene ty in HEK293 cells stably 1O transfected with the human and murine PRLR. ln Figpre 13A the human PRLR- ent activity is plotted against the antibody concentrations, while Figure 138 shows the murine PRLR-dependent activity. The luciferase activity is given as tage of the maximal luciferase activity obtained without addition of any antibody.

The |C50 values were determined for the following antibodies in lth format: Mat3 (closed circles), |C5o = 0.5 nM (Fig. 13A, hPRLR) and 1.3 nM (Fig. 138, mPRLR); HE06.642 (open squares), |C50 = 4.6 nM (Fig. 13A, hPRLR) and >>1333 nM (= 20 pg/ml) (Fig. 138, mPRLR); unspecific isotype control antibody (open triangles): no inhibitory effect (see Figure 13A and B). These data show the improved activity of Mat3 on hPRLR compared to HE06.642 and demonstrate the activity of Mat3 on mPRLR whereas 42 does not inhibit mPRLR-dependent luciferase activity.

Figure 14: Cell binding of neutralizing PRLR antibodies on cells expressing PRLR from human, mouse and monkey using flow cytometry. The median fluorescent signal intensity is plotted against the antibody concentration. The following lgG1 antibodies were applied: Mat3 d circles), HEO6.642 (open squares), unspecific isotype control antibody (open triangles). Different cell lines were tested: A) HEK293 cell line stably transfected with human PRLR, B) HEK293 cell line stably transfected with murine PRLR, C) HEK293 cell line not ected with any PRLR gene (negative control cell line), D) human breast cancer cell line T47D, E) BaF3 cell line stably transfected with rhesus monkey PRLR, F) BaF3 cell line stably transfected with human PRLR, G) BaF3 cell line stably transfected with murine PRLR. The cell line g potency of the antibodies on the different cell lines have been d from the dose-response curves as E050 values (see Table 8). The dose-response plots indicate the superior cell binding properties of Mat3 compared to HE06.642.

Seq ID NO:1 represents amino acid sequence of VH, Mat3 Seq ID NO:2 represents amino acid sequence of VL, Mat3 Seq ID N023 represents nucleic acid sequence VH, Mat3 Seq ID N024 represents nucleic acid sequence VL, Mats Seq ID NO:5 ents amino acid sequence of HCDR1, Mat3 Seq ID NO:6, represents nucleic acid ce HCDRZ, Mat3 Seq ID NO:7 represents nucleic acid sequence HCDR3, IVIatB Seq ID NO:8 represents nucleic acid sequence LCDR1, Mat3 Seq ID NO:9 represents nucleic acid ce LCDRZ, Mat3 1O Seq ID NO:1O represents nucleic acid sequence LCDRS, Mat3 Seq ID NO:11 represents amino acid sequence of ellular domain of lgus and rhesus monkey PRLR fused to Fc-His Seq ID NO:12 represents human ECD_PRLR, amino acid position 1 — 210, S1 domain 1-100 (S1 domain construct 1-102),SZ domain 101-210 Seq ID NO:13 represents murine ECD_PRLR, amino acid position 1 — 210 Seq ID NO:14 represents amino acid sequence of VH, HE06642, Novartis (W02008/22295) Seq ID NO:15 ents amino acid sequence of VL, HE06642, Novartis (W02008/22295) Seq ID NO:16 represents nucleic acid sequence VH, HE06642, Novartis (W02008/22295) Seq ID NO:17 represents nucleic acid sequence VL, HE06642, Novartis (W02008/22295) EXAMPLES Example 1 Inhibition of rolactin—induced ration of BaF3 cells monoclonal cells stabl transfected with human rolactin rece tor b neutralizin rolactin rece tor antibodies and unspecific control antibodies.

To analyze the in vitro efficacy of the neutralizing PRLR antibodies, the inhibition of tin-activated cellular proliferation of BaF3 cells was used. The cells were stably transfected with human PRLR and were ely cultured in RPMI containing 2 mM 1O glutamine in the presence of 10% FCS and 10 ng/ml of human prolactin. After six hours of tion in tin-free medium containing 1% FCS, cells were seeded into 96- well plates at a density of 25000 cells per well. Cells were stimulated with 35 ng/ml prolactin and coincubated with sing doses of neutralizing PRLR antibodies for two days. Cellular proliferation was analyzed using a CellTiter—Glo Luminescent Cell ity Assay (Promega). Dose-response curves for the tion of prolactin- stimulated cellular growth were generated and IC50 values calculated. As negative control, stimulation with an unspecific control antibody was used. Antibody Mats was tested in comparison to antibody HE 06.642 (both were in the IgG1 format) (Figure 9).

Example2 Inhibition of prolactin-induced eration of BaF3 cells (monoclonal cells stably transfected with the murine rolactin rece tor b neutralizin rolactin rece tor antibodies and ific control antibodies.

To analyze the in vitro efficacy of the neutralizing PRLR antibodies, the inhibition of prolactin-activated cellular proliferation of Ba/FB cells was used. The cells were stably transfected with the murine PRLR and were routinely cultured in RPMI containing 2 mM glutamine in the presence of 10% FCS and 10 ng/ml of human prolactin. After six hours of starvation in prolactin-free medium containing 1% FCS, cells were seeded into 96- well plates at a density of 20000 cells per well. Cells were stimulated with 50 ng/ml 3O prolactin and coincubated with increasing doses of neutralizing PRLR dies for three days. Cellular proliferation was analyzed using a CellTiter-Glo Luminescent Cell Viability Assay (Promega). Dose-response curves for the tion of prolactin- stimulated cellular growth were generated and IC50 values calculated. As negative control, stimulation with an unspecific control antibody was used. Antibody Mat3 was tested in comparison to antibody HE 06.642 (both were in the IgG1 format) (Figure 10).

Example 3 tion of rolactin—induced roliferation of BaF3 cells monoclonal cells stabl transfected with the rhesus {Lolactin recewr) by neutralizing prolactin receptor dies and unspecific control antibodies.

To analyze the in vitro efficacy of the neutralizing PRLR antibodies, the tion of prolactin-activated cellular proliferation of Ba/F3 cells was used. The cells were stably transfected with the rhesus PRLR and were routinely cultured in RPMI containing 2 mM glutamine in the presence of 10% FCS and 10 ng/ml of human tin. After six hours of starvation in prolactin-free medium containing 1% FCS, cells were seeded into 96- 1O well plates at a density of 25000 cells per well. Cells were stimulated with 100 ng/ml prolactin and coincubated with increasing doses of neutralizing PRLR antibodies for two days. Cellular proliferation was analyzed using a CellTiter—Glo Luminescent Cell Viability Assay (Promega). Dose-response curves for the inhibition of prolactin- stimulated cellular growth were generated and IC50 values calculated. As negative control, stimulation with an unspecific control antibody was used. Antibody Mat3 was tested in comparison to antibody HE 06.642 (both were in the lgG1 format) (Figure 11).

Example 4 Quantitative is of prolactin and prolactin receptor gene expression by ime TagMan PCR analysis in eu- and ectopic endometrium and endometriotic lesions from patients and y controls.

Real—timeTaqman PCR analysis was performed using the ABI Prism 7700 Sequence Detector System according to the manufacturer’s ctions (PE Applied Biosystems) and as described Endocrinolgy 2008, 149 (8): 3952—3959) and known by the expert in the field. Relative expression levels of PRL and the PRLR were normalized to the expression of cyclophyllin. We analyzed the expression of PRL and the PRLR in the endometrium from healthy women and in endometrium and endometriotic lesions from ts by using quantitative real-time Taqman PCR is. The expression of prolactin and its receptor was clearly lated in endometriotic lesions compared to healthy endometrium or endometrium derived from patients.

Results are shown in Figure 1 and 2.

These findings imply that autocrine prolactin signalling plays a role in the development and nance of endometriosis and adenomyosis uteri (endometriosis interna, a form of endometriosis restricted to the uterus.

WO 63932 Example 5 ent of adenomyosis uteri g: endometriosis interna) in SHN mice with neutraliziflg PRLR antibody Mat3.

To test the cy of neutralizing PRLR antibodies in endometriosis, the adenomyosis uteri model in SHN mice relying on systemic hyperprolactinemia was employed (Acta anat. 116:46—54,1983). Hyperprolactinemia in SHN mice was d by pituitary isografting under the kidney capsule of 7 weeks old female mice (Acta anat. 116246— 54,1983). Neutralizing PRLR antibody Mat3 (30 mg/kg; 10 mg/kg, 3 mg/kg, 1 mg/kg) or ific antibody (30 mg/kg) were administered subcutaneously starting two weeks 1O after pituitary isografting. Animals were treated once weekly with the antibodies for seven weeks. The infiltration of the uterine muscular layer by glandular tissue was assessed as described previously (Laboratory Animal e 1998,48264-68). At autopsy (day 66 after pituitary transplantation), uteri were fixed overnight in buffered 4% formalin and embedded in paraffin. The degree of adenomyosis (=endometriosis interna) was assessed as follows: Grade 0 = no adenomyosis Grade 1 = the inner layer of the myometrium looses its tric orientation Grade 2 = endometrial glands invading the inner layer of the myometrium Grade 3 = endometrial glands between the inner and outer layer of the uterine myometrium Grade 4 = endometrial glands invading the outer layer of the uterine myometrium Grade 5 = endometrial glands outside of the outer layer of the e myometrium The experiment comprised the following experimental groups: 1. Animals without pituitary transplantation, i.e. normoprolactinemic mice 2. Animals with pituitary transplantation, i.e. hyperprolactinemic mice Animals with pituitary transplantation, treated with unspecific control dy once weekly at a dose of 30 mg/kg 4. Animals with ary lantation, treated with the neutralizing prolactin receptor antibody Mat3 in the murine lgG2a format once weekly at a dose of mg/kg . Animals with pituitary transplantation, treated with the neutralizing prolactin receptor antibody Mat3 in the murine lgG2a format once weekly at a dose of mg/kg WO 63932 6. Animals with pituitary transplantation, treated with the neutralizing prolactin or antibody Mat3 in the murine lgG2a format once weekly at a dose of 3 mg/kg 7. s with pituitary transplantation, treated with the neutralizing prolactin or antibody Mat3 in the murine lgGZa format once weekly at a dose of 1 mg/kg The neutralizing PRLR antibody Mat3 ted endometriosis a omyosis) (Figure 12). The neutralising PRLR antibody Mat3 is therefore suitable to treat 1O endometriosis interna (= adenomyosis uteri) and endometriosis externa in women.

Example 6 Neutralizing PRLR antibody Mat3 is suitable for the treatment of benign breast e.

An activating PRLR mutation or local or systemic hyperprolactinemia can provoke benign breast disease. Therefore, a hyperprolactinemic mouse model with enhanced eration in the mammary gland (hallmark of the most severe forms of benign breast disease) was employed. 12 weeks old female Balb/c mice received a pituitary isograft under the kidney capsule or remained unoperated. ary isografted mice remained untreated or were treated subcutaneously once weekly with lizing PRLR antibody Mat3 in the lgGZ format (= lgG2 Mat3) or unspecific control antibody in lgGZ format on day 15, 22, 29, and 36 after pituitary transplantation. Antibody doses were 30 mg/kg.

Experimental group size was 8 animals.

The experiment comprised the following experimental groups: 1. Animals without pituitary transplantation, i.e. normoprolactinemic mice 2. Animals with pituitary lantation, i.e. rolactinemic mice Animals with pituitary transplantation, treated with unspecific control antibody once weekly at a dose of 30 mg/kg 4. Animals with pituitary transplantation, treated with the neutralizing prolactin receptor antibody Mat3 once weekly at a dose of 30 mg/kg On day 38 after pituitary transplantation mice were sacrificed. Two hours before death, animals received an intraperitoneal injection of BrdU to monitor epithelial cell proliferation. The left inguinal mammary gland was fixed in Carnoy’s solution and mammary gland whole mounts were prepared and stained with Carmine alaune. Side- branching was evaluated in the mammary gland whole mounts. Results are depicted in Figure 3A. Antibody Mat3 inhibited sidebranching in the mammary gland, unspecific control antibody was without effect (Figure 3A).

Afterwards the mammary gland whole mounts were embedded in paraffin and BrdU immunostainings were med as described previously (Endocrinology 149 (8): 3952-3959; 2009). Epithelial cell proliferation was analysed in 4 histological mammary gland slices per animal.

The l one third of the right inguinal mammary gland without the lymph node was frozen in liquid nitrogen and processed for RNA preparation. After reverse transcription, real-time Taqman PCR analysis was performed using the ABI Prism 7700 Sequence 1O Detector System according to the cturer’s ctions (PE Applied Biosystems).

Expression of the prolactin target gene elf5 was assessed and normalized to cytokeratin18 expression. ve mRNA levels were ated by the comparative ACT-method. Pituitary isografting, i.e. hyperprolactinemia ed expression of the prolactin target gene elf5 (Figure SB). Specific antibody Mat3, but not the unspecific l antibody inhibited elf5 gene expression indicating successful blockade of the tin receptor (Figure 3B).

Antibody Mat3 is therefore suitable to treat benign breast disease.

Example 7 Isolation of target-specific antibodies from human antibody phage display libraries To isolate a panel of antibodies able to neutralize the activity of human PRLR, three human antibody phage display libraries, expressing Fab and scFv fragments, were investigated in parallel. The target used for the library panning was the soluble extracellular domain (ECD) of the human and mouse prolactin receptor, respectively, represented by the amino acids 1-210, of SEQ ID NOs. 12 and 13. .Alternative targets were the ECD of PRLR inally linked to six histidines or to a human lgG1-Fc domain via the linker with the amino acid sequence "isoleucine-glutamate-glycinearginine —methionine-aspartate”.

Selection of target-specific antibodies from phage y was carried out according to methods described by Marks et al. (Methods Mol Biol. 1-76, 2004). The phage display library was ted with 50 pmols of the biotinylated ECD at room temperature for 1 hr and the complex formed was then captured using 100 pl of Streptavidin beads suspension (Dynabeads ® M-280 Streptavidin, lnvitrogen). Non specific phages were removed by g the beads with wash buffer (PBS + 5% Milk,). Bound phages were eluted with 0.5 ml of 100 anl Triethylamine (TEA,) and immediately neutralized by addition of an equal volume of IM TRIS-CI pH 7.4. Eluted phage pool was used to infect TG1 E coli cells growing in logarithmic phase, and phagemid was rescued as described (Methods Mol Biol. 248:161-76, 2004),. Selection was repeated for a total of three rounds. Single colonies obtained from TG1 cells infected with eluted phage from the third round of panning were screened for binding ty in an ELISA assay. Briefly, single colonies obtained from the TGI cell infected with eluted phage were used to inoculate media in 96—well plates.

Microcultures were grown to an 0.6 at which point expression of soluble 1O antibody fragment was induced by on of 1 mM IPTG following overnight culture in a shaker tor at 30°C. Bacteria were spun down and periplasmic extract was prepared and used to detect antibody binding activity to ECD immobilized on l microplates (96-well flat bottom Immunosorb plates, Nunc) following standard ELISA protocol provided by the microplate manufacturer.

The affinities of the anti-Prolactin Receptor (PRLR) antibodies for binding to the recombinant extracellular domain (ECD) were ted using the Biacore® 2000 and used for affinity ranking of antibodies.

Example 8 Maturation of antibody ts: Antibody affinity maturation is a two step process where saturation mutagenesis and well-based high hput screening are combined to identify a small number of ons resulting in affinity increases. In the first round of affinity maturation positional diversification of wild-type antibody is introduced by site-directed mutagenesis using NNK-trinucleotide cassettes (whereby N represents a 25% mix each of adenine, e, guanine, and cytosine nucleotides and K represents a 50% mix each of thymine and guanine nucleotides) according to BMC Biotechnology 7: 65, 2007. This way, all 20 amino acids are introduced at an individual amino acid on. This positional randomization is restricted to the six complementarity determining regions . In the second round of affinity maturation beneficial substitutions were recombined and screened for further improvements.

Screening of maturated 04” Fab variants by ELISA tests: 96 well iter plates were coated with 1 pg per milliliter of human PRLR. Plates were incubated over night at 4°C. After blocking with PBS buffer containing 3% bovine serum albumin, ized E.coli-derived supernatants containing the Fab variants were added. Detection of formed complexes occurred via the addition of an anti-flag antibody (Sigma, A8592) labeled with horseradish peroxidase.

Amplex Red as genic substrate for horseradish dase was added and incubated for 30 minutes at room temperature. Absorption at 570 nm and extinction at 585 nm was measured using the Tecan Infinite F500 reader. The obtained results the screening hit O42” are shown in Figure 7. dual substitutions in the ing hit “00520-2” (Figure 7) beneficial for affinity improvement were evaluated regarding their influence on thermostability of the antibody, in order to ensure 1O ative unfolding of the Fab domain during denaturation by temperature elevation.

The antibody Mat3 was a derivative of “00520-2”, in which the thermo- destabilizing substitutions have been reversed to the parental antibody “005-004”.

Example 9 Cross-reactivity of antibodies on mouse and human PRLR expressed on cell surfaces a) In order to understand the missing antiproliferative ty of antibody HE06642 on cells carrying the murine PRLR, the binding characteristics of HE06642 on mouse and human PRLR expressed on cells was determined by flow cytometry on HEK293 cells stably expressing the human and murine PRLR, respectively. The cells as well as the al HEK293 cell line without PRLR were harvested, centrifuged and resuspended at approximately 5x106 cells/ml in 1xPBS containing 2% FBS and 0.1 % sodium azide (FACS ). The antibody HE06642 was diluted to 2-fold final concentration in FACS buffer and added to appropriate sample wells (50 pl / well). For secondary antibody and autofluorescence controls, 50 pl FACS buffer was added to appropriate wells. 50 pl of cell suspension was added to each sample well. Samples were incubated at 4°C for one hour, washed twice with cold FACS buffer and resuspended in FACS buffer containing PE-conjugated goat anti-human IgG at a 1:100 dilution. Following a 30 min incubation at 4°C, cells were washed twice with cold FACS buffer, resuspended in FACS buffer containing 1 mg/ml propidium iodide rogen, San Diego, CA) and analyzed by flow cytometry. As shown in Figure 5A, the antibody HE06.642 only binds to the human PRLR and not to the murine PRLR. This observation is tent with the finding reported in Example 2 and 12 about the missing activity of 42 in the murine PRLR-dependent proliferation and luciferase reporter gene assays. b) In order to demonstrate cell binding of antibody Mat3 on cells carrying the human and the rhesus monkey PRLR, of which the amino acid sequence of the extracellular domain is identical to the one of cynomolgus monkey, the binding characteristics of Mat3 on human and monkey PRLR expressed on cells was determined by flow cytometry on HEK293 cells stably expressing the human and monkey PRLR, respectively. The cells were harvested, centrifuged and resuspended at approximately 2x108 cells/ml in 1xPBS containing 3% FBS and 0.05 % sodium azide (FACS buffer).

The antibody Mat3 was diluted to 2-fold final concentration in FACS buffer and added to appropriate sample wells (50 pl / well). For secondary antibody and autofluorescence controls, 50 pl FACS buffer was added to appropriate wells. 50 pl of cell suspension was added to each sample well. Samples were incubated at 4°C for one hour, washed 1O twice with cold FACS buffer and resuspended in FACS buffer containing PE-conjugated goat uman IgG at a 1:100 dilution. Following a 30 min incubation at 4°C, cells were washed twice with cold FACS buffer, resuspended in FACS buffer containing 1 mg/ml propidium iodide rogen, San Diego, CA) and analyzed by flow cytometry. As shown in Figure 5B, the antibody Mat3 binds to the human PRLR as well as to the monkey PRLR. Maximal signal intensities at highest antibody trations depend on the number of RLR expressed on the cell surfaces, i.e. HEK293 and Ba/F cells do not carry the same number of PRLRs on their surface. The EC50 values were calculated based on the dose se curves illustrated in Figure 5B, in order to derive a measurement value for binding strength of Mat3 on cells (Table 2). The cell-based binding potency of Mat3 was 0.53 nM on HEK293 cells with human PRLR and 2.94 nM on Ba/F cells with monkey PRLR. These data support the finding that Mat3 is not only a very potent human-specific agent, but also at reasonable doses active on monkey PRLR in the low nanomolar range.

Example 10 Binding studies with purified extracellular PRLR domains using surface plasmon resonance analysis Binding affinities of dy Mat3 were determined by surface plasmon resonance analysis on a Biacore T100 instrument (GE Healthcare Biacore, lnc.). Antibodies were immobilized onto a CM5 sensor chip through an ct capturing reagent, anti-human IgG Fc. ts from the “Human Antibody Capture Kit” (BR-1008—39, GE Healthcare Biacore, Inc.) were used as bed by the cturer. Approximately 5000 RU monoclonal mouse anti-human IgG (Fc) antibody were immobilized per cell. Antibody Mat3 was injected at a concentration of 5pg/ml at 10p|lmin for 10 sec to reach a ing level of approximately 200 to 600 RU. Various concentrations (400 nM, 200 nM, 100 nM, 50 nM, 25 nM, 12.5 nM, 6.25 nM, and 3.12 nM) in HEPES—EP buffer (GE Healthcare Biacore, Inc.) of the ECD of human, monkey or murine PRLR were injected over immobilized Mat3 antibody at a flow rate of 60 uI/min for 3 minutes and the dissociation was allowed for 10 minutes. The ECDs of the human PRLR (SEQ ID NO: 12), of the monkey PRLR (SEQ ID NO: 11, after proteolytic removal of the Fc—His-tag via Factor Xa digestion) and of the murine PRLR (SEQ ID NO: 13) represented monovalent analytes. rams were generated after in-Iine reference cell correction followed by buffer sample subtraction. The dissociation equilibrium constant (K9) was ated based on the ratio of association (kon) and dissociation rated (koff = kd) constants, ed by fitting sensograms with a first order 1:1 binding model using 1O BiaEvaluation Software. The monovalent dissociation constants (KD, affinity) and dissociation rates (kd = koff) values are shown in Table 1. e 11 Peptide scan a) Peptide synthesis: To reconstruct discontinuous epitopes of the target molecule SEQ ID NO. 12 from amino acid position 1 to 210, the ECD of the human PRLR, a y of ured peptides was synthesized. This was done using Pepscan’s proprietary Chemically Linked es on Scaffolds (CLIPS) technology (Timmerman et al., 2007, J. Mol. 2O Recognit. 20283-99; n Therapeutics, Lelystad, Netherlands). CLIPS technology allows to structure peptides into single loops, double-loops, triple loops, sheet-like folds, helix-like folds and combinations thereof. CLIPS templates were coupled to cysteine residues. The side—chains of multiple nes in the peptides were coupled to one or two CLIPS templates. For e, a 0.5 mM solution of the T2 CLIPS template 1,3-bis (bromomethyl) benzene was dissolved in ammonium bicarbonate (20 mM, pH 7.9)/acetonitrile (1:1(v/v). This solution was added onto the peptide arrays. The CLIPS template bound to side—chains of two cysteines as present in the solid—phase bound peptides of the peptide-arrays (455 wells plate with 3 ul wells). The peptide arrays were gently shaken in the solution for 30 to 60 minutes while completely d in solution.

Finally, the peptide arrays were washed extensively with excess of H20 and sonicated in disrupt-buffer containing 1 percent SDS/O.1 percent beta-mercaptoethanol in PBS (pH 7.2) at 70°C for 30 minutes, followed by sonication in H20 for another 45 minutes.

The T3 CLIPS carrying peptides were made in a similar way but now with three cysteines.

The binding of antibody Mat3 and of antibody HE06642 to each peptide was tested in a N-based ELISA (Slootstra et al., 1996, Molecular Diversity 1: 87-96). The peptide arrays were pre-incubated with 5% to 100%-binding buffer (1 hr, 20°C). The binding buffer was composed of 1% Tween-80, 4% horse-serum, 5% Ovalbumin (WM and was diluted with PBS. After washing the peptide arrays were incubated with primary antibody solution (1 to 5 ug/ml) in PBS containing 1% Tween-80 (overnight at 4°C).

After washing, the peptide arrays were incubated with a 1/1000 dilution in 100% binding 1O buffer of an antibody peroxidase conjugate for one hour at 25°C (anti-human, humpo).

After washing, the dase substrate 2,2’-azino-di—3-ethylbenzthiazoline sulfonate (ABTS) and 2 microliters/milliliter of 3 percent H202 were added. After one hour, the color development was measured. The color development was quantified with a charge d device (CCD) - camera and an image processing system. 0) Data processing: The raw data were l values obtained by a CCD-camera. The values ranged from 0 to 3000 mAU, similar to a standard 96-well plate ELISA—reader. The results were quantified and stored into the Peplab database. The binding values were ted for analysis. Occasionally a well contained an bble resulting in a false-positive value, the cards were manually inspected and any values caused by an bble were scored as 0. d) Data analysis and representation: A heat map is a graphical representation of data where the empirical values from experimental data are organized in a two-dimensional map, and are then represented as colors (Brinton, 1914, Graphic Methods for Presenting Facts, New York: The ering Magazine Company; Gower and Digby, 1981, ), “Expressing complex relationships in two dimensions” in Interpreting Multivariate Data, ed. Barnett, V., Chichester, UK: John Wiley & Sons, pp. 83-118.). For double-looped CLIPS peptides, such a two-dimensional map could be derived from the independent sequences of the first loop and the second loop.

For the target protein (ECD of human PRLR), the 2916 CLIPS peptides had sequences that were ively permutations of 54 unique quences, combined in two sequential CLIPS loops. Thus, the observed Pepscan ELISA data could be plotted in a 2012/060078 54x54 matrix, where each X nate was the amino acid sequence of the first loop, and each Y coordinate was the amino acid sequence of the second loop. For each XY nate in the matrix, the Pepscan ELISA value was placed that is derived from the e with sequence X+Y. To further facilitate the visualization, Pepscan ELISA values were replaced with colors from a continuous gradient. In this case, extremely low values were colored green, extremely high values were colored red, and average values were d black. When this color map was applied to the described data matrix, a color heat map resulted. The peptides revealing the most striking differences in the ELISA results between the antibodies Mat3 and 2 were selected based 1O on these heat map representation. For these peptides, each ELISA signal value was processed for representation in a bar plot (Figure 8A and BB). Each plotted value represented the average value obtained for 54 peptides with S.E.IVI (standard error of mean). The data was normalized to average over the entire 2916 peptide dataset and corrected for ound signal.

Figure 8A shows the ELISA s for a subset of peptides ranging from amino acids 103-PDPPLELAVEVKQPE-117 indicated as “117’ on the X-axis to 127- WSPPTLIDLKTGWFT-141 (indicated as ‘141’). l. e. these peptides, which were shifted by three amino acids along the ECD amino acid sequence, cover the region from amino acid position 103 to 141 of the ECD of human PRLR. The est differences observed within this t are for peptide 109-LAVEVKQPEDRKPYL-123 (indicated as ‘123’) with a significance p-value of 4x10”, and for peptide 121- PYLWIKWSPPTLIDL-135 (indicated as ‘135’) with a significance p-value of 7x104“.

Figure 8B shows the ELISA results for a subset of peptides ranging from 139- WFTLLYEIRLKPEKA—153 (indicated as ‘153’ on the X—axis) to 163- QQTEFKILSLHPGQK-177 (indicated as ‘177’). I. e. these peptides, which were shifted by three amino acids along the ECD amino acid ce, cover the region from amino acid position 139 to 177 of the ECD of human PRLR. The strongest differences observed within this dataset are for peptide 148-LKPEKAAEWEIHFAG-162 (indicated as ‘162’) with a significance p-value of 6x10'25, and for peptide 160- FAGQQTEFKILSLHP-174 (indicated as ‘174’) with a significance p-value of 8x108.

These data demonstrate that both antibodies bind to the 82 subdomain of the ECD of human PRLR (amino acid 101 to 210) and therefore are non-competitive to the l ligand PRL which mainly binds to the S1 domain. However, this peptide scan showed that there are differences in binding to the 82 domains between Mat3 and HE06642.

WO 63932 This finding indicates why the antibody Mat3 shows a different s-specificity and potency ed to HE06642.

Example 12 Inhibition of luciferase reporter gene ty in HEK293 cells stably transfected with the human and murine PRLR To further analyze the in vitro activity of the neutralizing PRLR antibody Mat3 on the human and the murine PRLR, a reporter gene assay was used. HEK293 cells stably transfected with the murine PRLR were transiently transfected with a luciferase er 1O gene under the control of LHREs (lactogenic hormone response elements) . Afterwards, cells were seeded at a density of 20000 cells per well (80 pl) on a 96-well plate in DMEM High e medium with 4,5g/L glucose, 2mM Glutamax, 0.5% FCS, and 1% Penicillin/Streptomycin. The next day 200 ng/ml human prolactin (10 pl) with and without increasing doses of test antibodies (10 pl) were added. Twenty-four hours later, luciferase activity was determined. For comparison, the antibody HE06642 and a non- specific antibody targeting choleratoxin called CTX were also tested. AII antibodies were tested as IgG1 molecules (Figure 13A and 138).

Example 13 Binding studies with purified extracellular PRLR domains USiflQ surface plasmon resonance analysis Binding affinities of antibodies Mat3 and HE06642 were determined by surface plasmon nce analysis on a Biacore T100 instrument (GE care Biacore, Inc.) in parallel. Antibodies were immobilized onto a CM5 sensor chip through an indirect capturing reagent, anti-human IgG Fc. Reagents from the “Human Antibody Capture Kit” (BR-1008—39, GE Healthcare Biacore, Inc.) were used as described by the manufacturer. imately 5000 RU onal mouse anti-human IgG (Fc) antibody were immobilized per cell. Each test antibody was injected at a concentration of 5pg/ml at 10pllmin for 10 sec to reach a capturing level of approximately 200 to 600 RU. Various concentrations (400 nM, 200 nM, 100 nM, 50 nM, 25 nM, 12.5 nM, 6.25 nM, and 3.12 nM) in HEPES—EP buffer (GE care Biacore, Inc.) of the ECD of human, monkey or murine PRLR were injected over the immobilized test antibody at a flow rate of 60 pI/min for 3 minutes and the dissociation was allowed for 10 minutes.

The ECDs of the human PRLR (SEQ ID NO: 12), of the monkey PRLR (SEQ ID NO: 11, after proteolytic removal of the Fc-His-tag via Factor Xa digestion) and of the murine PRLR (SEQ ID NO: 13) represented monovalent analytes. Sensograms were generated after in-line reference cell correction followed by buffer sample subtraction. The dissociation equilibrium constant (KD) was ated based on the ratio of association (kon) and dissociation rated (koff = kd) nts, obtained by fitting sensograms with a first order 1:1 binding model using BiaEvaluation Software (see Table 7).

Table 7: lent dissociation nts and dissociation rates of purified extracellular domains of human, monkey and murine PRLR (expressed in HEK293 cells) determined for Mat3 and HE06.642 by surface plasmon resonance Human PRLR Monkey PRLR Murine PRLR Kn [M] Kd [11s] KD [M] Kd [1/s] KD [M] Kd [1/s] Mat3 1.3x10'9 4.14X10‘4 ‘9.6X10'9 1.02X10'3 0.4X10'9 1.64x10'4 LHE06.642# j0.8x10'9 5.33x10-4 17 x10-9 5.-70x103 150x109L10x1U #The affinities disclosed for HE06642 in W02008/022295 are KD (human PRLR): 2.6x10'9 lvl, KD (monkey PRLR) = 38.9 x10'9 M, and KD (murine PRLR) = 2.7 x10‘9 M.

As shown in Table 7, Mat3 ts improved affinities to monkey and murine PRLR compared to HE06.642. The improved cell g and antiproliferative activity of Mat3 on human PRLR is not reflected by improved affinity to hPRLR compared to HE06.642.

Despite binding to the purified ECD of murine PRLR, HE06.642 does not bind cells or inhibits proliferation of cells sing the murine PRLR (Figure 10 and 14, Table 8). In st, Mat3 blocks cell proliferation in nanomolar to subnanomolar scale in all three species.

Additionally, the soluble ECD-PRLR (SEQ ID NO: 12) was captured on the surface via the immobilized test antibodies Mat3 and HE06642, ore, the epitope of the capture antibody was blocked for all bound ECD-PRLR molecules. Human PRL was immediately passed over the surface to bind to the immobilized ECD-PRLR. This way, it could be measured whether PRL bound the ECD-PRLR, although the ECU is captured by the test antibody.

It could be observed that PRL binds the ECD-PRLR independently from binding to Mat3 and HE06.642. Thus, both dies do not compete with the natural ligand PRL on ECU-PRLR.

Example 14 inding studies of antibodies on various cell lines expressing human, mouse and A cell binding study was performed with antibody Mat3 and HE06642 as well as a choleratoxin-specific isotype control, all being in lgG1 format. The tested cell lines were HEK293 cells stably sing human and mouse PRLR, respectively, the human breast cancer cell line T47D as well as the Ba/F cell lines expressing human, mouse and rhesus monkey PRLR. The cell g was determined by flow cytometry on the above mentioned cells. The cells were harvested, centrifuged and resuspended at 1O imately 2x106 cells/ml in 1xPBS containing 3% FBS and 0.05 % sodium azide (FACS buffer). Each test antibody was diluted to 2-fold final concentration in FACS buffer and added to appropriate sample wells (50 pl / well). For secondary antibody and autofluorescence controls, 50 pl FACS buffer was added to appropriate wells. 50 pl of cell suspension was added to each sample well. Samples were incubated at 4°C for one hour, washed twice with cold FACS buffer and ended in FACS buffer containing PE-conjugated goat anti-human lgG at a 1:100 on. Following a 30 min incubation at 4°C, cells were washed twice with cold FACS buffer, resuspended in FACS buffer containing 1 mg/ml ium iodide (lnvitrogen, San Diego, CA) and analyzed by flow cytometry.

The obtained data are shown as dose-response curves in Figure 14. From these curves EC50 values were deduced indicating the cell binding potencies (Table 8). In conclusion, the data indicate the superior cell binding properties of Mat3 compared to HE06.642 across the different PRLR-expressing cell lines.

Table 8: Cell g potency of neutralizing PRLR antibodies Mat3 and He06.642 in lgG1 format on cells expressing PRLR from human, mouse and monkey deduced from flow cytometry Cell line Cell binding (ECso [M]) HE06.642 HEK293-human PRLR HEK293-murine PRLR HEK293 wlo PRLR Human T470 BaF3-rhesus PRLR BaF3-human PRLR BaF3-mouse PRLR *no icant binding; # dose-response diagrams in Figure 14

Claims (35)

What we claim is:

1. Antibody or antigen-binding fragment thereof which antagonizes tin receptormediated signaling, whereby the antibody or antigen-binding fragment f ses a variable heavy chain ning the CDR sequences of SEQ ID NO: 5, 6 and 7 and a variable light chain containing the CDR sequences of SEQ ID NO: 8, 9, and 10.

2. Antibody or antigen-binding fragment thereof ing to claim 1, whereby the variable heavy chain has an amino acid sequence of SEQ ID NO: 1, and the variable light chain has an amino acid sequence of SEQ ID NO: 2.

3. Antibody or antigen-binding fragment thereof according to claim 1 or 2, whereby the dy or antigen-binding fragment thereof comprises an antigen-binding region that binds specifically to one or more regions of the extracellular domain of PRLR from human, monkey and mouse.

4. Antibody or antibody-binding fragment f according to claim 3, whereby the human PRLR has an amino acid sequence according to positions 1 to 210 of SEQ ID NO: 12 or human polymorphic variants of SEQ ID NO: 12, the monkey PRLR has an amino acid sequence according to positions 1 to 210 of SEQ ID NO: 11, and the mouse PRLR has an amino acid sequence according to SEQ ID NO: 13.

5. Antibody or antigen-binding fragment thereof ing to claim 3 or 4, whereby the affinity to the extracellular domain of PRLR from human, monkey and mouse is from 100 nM to 0.1 nM.

6. Antibody or antigen-binding fragment thereof according to claim 5, whereby the affinity is 0.1 nM.

7. Antibody or antigen-binding fragment thereof according to any one of claims 1 to 4, whereby the antibody consists of an antigen-binding region that binds specifically to one or more regions of the extracellular domain of human PRLR and whereby the affinity is from 10 nM to 0.1nM.

8. Antibody or antigen-binding fragment thereof according to any one of claims 1 to 7 wherein the heavy chain constant domain is a modified or unmodified IgG1, IgG2, IgG3 or IgG4.

9. An isolated c acid molecule encoding an antibody or antigen-binding fragment thereof according to any one of the claims 1 to 8.

10. An isolated c acid molecule according to claim 9, whereby the isolated nucleic acid molecule has a sequence selected from SEQ ID NO: 3 and 4.

11. sion vector comprising a nucleic acid molecule of claim 9 or 10.

12. Host cell sing the expression vector of claim 11 or the nucleic acid molecule of claim 9 or 10, whereby the host cell is a higher eukaryotic host cell, a lower eukaryotic host cell, or a prokaryotic cell, ed said host cell is not within a human.

13. Host cell of claim 12, y the higher eukaryotic host cell is a mammalian cell.

14. Host cell of claim 12, whereby the lower eukaryotic host cell is a yeast cell.

15. Host cell of claim 12, whereby the prokaryotic cell is a bacterial cell.

16. A method of using the host cell of any one of claims 12 to 15 to produce an antibody or antigen-binding fragment thereof, comprising culturing the host cell under suitable conditions and recovering said antibody or antigen-binding fragment thereof.

17. An antibody or antigen-binding fragment thereof produced by the method of claim 16.

18. An antibody or antigen-binding fragment f of any one of claims 1 to 8 that is purified to at least 95% homogeneity by .

19. An antibody or antigen-binding fragment according to any one of claims 1 to 8 as a medicament.

20. A pharmaceutical composition comprising the antibody or antigen-binding fragment thereof according to any one of claims 1 to 8 and a pharmaceutically acceptable carrier comprising excipients and auxiliaries.

21. Kits comprising a therapeutically effective amount of the antibody or antigen-binding fragment thereof of any one of claim 1 to 8, packaged in a container, said kit optionally containing a second therapeutic agent, and further comprising a label attached to or packaged with the container.

22. Use of an antibody or antigen-binding nt according to any one of claims 1 to 8 in preparation of a medicament for the treatment and/or prevention of endometriosis and adenomyosis.

23. Use of an dy or antigen-binding fragment according to any one of claims 1 to 8 in preparation of a medicament for the treatment and/or prevention of benign breast disease and mastalgia.

24. Use of an antibody or antigen-binding nt according to any one of claims 1 to 8 in preparation of a medicament for the treatment and/or prevention of antiestrogen-resistant breast cancer.

25. Pharmaceutical composition according to claim 20 comprising the antibody or antigenbinding fragment thereof according to any one of claims 1 to 8, in combination with at least one other agent.

26. An antibody or antigen-binding fragment thereof according to claim 1, substantially as herein described or exemplified.

27. An isolated nucleic acid molecule according to claim 9, ntially as herein described or ified.

28. An sion vector according to claim 11, substantially as herein described or exemplified.

29. A host cell according to claim 12, substantially as herein described or exemplified.

30. A method according to claim 16, substantially as herein described or exemplified.

31. A pharmaceutical composition according to claim 20, substantially as herein bed or exemplified.

32. A kit ing to claim 21, substantially as herein described or exemplified.

33. A use according to claim 22, substantially as herein described or exemplified.

34. A use according to claim 23, substantially as herein described or exemplified.

35. A use according to claim 24, substantially as herein bed or exemplified. -