Disclosed is an antibody or antigen-binding fragment thereof, which antagonizes prolactin receptor-mediated signaling and wherein: a. the amino acid sequence of the HCDR1 is identical to SEQ ID NO: 6 (FSSYWMHW) in at least 7 of 8 amino acids, and b. the amino acid sequence of the HCDR2 is identical to SEQ ID NO: 12 (SDISSASSYTNYADSVKGR) in at least 14 of 19 amino acids, and c. the amino acid sequence of the HCDR3 is identical to SEQ ID NO: 17 (ARGLDARRMDY) in at least 8 of 11 amino acids, and d. the amino acid sequence of the LCDR1 is identical to SEQ ID NO: 23 (TGSSSNIGAGYVVH) in at least 12 of 14 amino acids, and e. the amino acid sequence of the LCDR2 is identical to SEQ ID NO: 28 (RNNQRPS) in at least 4 of 7, more preferred 5 of 7, or even more preferred 6 of 7 amino acids, and f. the amino acid sequence of the LCR3 is identical to SEQ ID NO: 33 (CAAWDDSLNGW) in at least 11 of 12 amino acids.
Neutralizing prolactin receptor antibodies and their therapeutic use