Anti-cd79b antibody-drug conjugate, and preparation method therefor and pharmaceutical use thereof

A ligand-drug conjugate or a pharmaceutically acceptable salt or solvate thereof, wherein:

• the drug is selected from the group consisting of a tubulin polymerization inhibitor, a Topo I inhibitor, and MMAE or a derivative thereof;
• and
• the ligand is an anti-CD79B antibody or an antigen-binding fragment thereof comprising:
• a heavy chain HCDR1 comprising a sequence set forth in SEQ ID NO:
• 24;
• a heavy chain HCDR2 comprising a sequence set forth in SEQ ID NO:
• 25;
• a heavy chain HCDR3 comprising a sequence set forth in SEQ ID NO:
• 26;
• a light chain LCDR1 comprising a sequence set forth in SEQ ID NO:
• 27;
• a light chain LCDR2 comprising a sequence set forth in SEQ ID NO:
• 11 or SEQ ID NO:
• 17;
• and
• a light chain LCDR3 comprising a sequence set forth in SEQ ID NO:
• 12 or SEQ ID NO:
• 18.