Anti-Siglec-15 antibody

An antibody or antigen binding fragment thereof comprising:

• a light chain sequence that comprises a light chain variable region having CDRL1, CDRL2, and CDRL3, wherein CDRL1 comprises the amino acid sequence of SEQ ID NO:
• 47, CDRL2 comprises the amino acid sequence of SEQ ID NO:
• 48, and CDRL3 comprises the amino acid sequence of SEQ ID NO:
• 49, and a heavy chain sequence that comprises a heavy chain variable region having CDRH1, CDRH2, and CDRH3, wherein CDRH1 comprises the amino acid sequence of SEQ ID NO:
• 44, CDRH2 comprises the amino acid sequence selected from the group consisting of SEQ ID NO:
• 45 and SEQ ID NO:
• 97, and CDRH3 comprises the amino acid sequence of SEQ ID NO:
• 46, wherein the antibody or antigen binding fragment thereof binds a Siglec-15 protein comprising the amino acid sequence of SEQ ID NO:
• 2 or 4,
• wherein the light chain sequence is selected from the group consisting of:
• (a) the light chain sequence comprises amino acid residues 21-238 of the amino acid sequence of SEQ ID NO:
• 69;
• (b) the light chain sequence comprises amino acid residues 21-238 of the amino acid sequence of SEQ ID NO:
• 105;
• (c) the light chain variable region comprises amino acid residues 21-133 of the amino acid sequence of SEQ ID NO:
• 69;
• and
• (d) the light chain variable region comprises amino acid residues 21-133 of the amino acid sequence of SEQ ID NO:
• 105
• or
• wherein the heavy chain sequence is selected from the group consisting of:
• (a) the heavy chain sequence comprises amino acid residues 20-466 of the amino acid sequence of SEQ ID NO:
• 101;
• (b) the heavy chain sequence comprises amino acid residues 20-466 of the amino acid sequence of SEQ ID NO:
• 99;
• (c) the heavy chain variable region comprises amino acid residues 20-140 of the amino acid sequence of SEQ ID NO:
• 101;
• and
• (d) the heavy chain variable region comprises amino acid residues 20-140 of the amino acid sequence of SEQ ID NO:
• 99.