Anti-lag-3 antibody and use thereof

An antibody or antigen-binding fragment thereof which is capable of specifically binding to LAG-3, comprising:

• (a) the following three heavy chain variable region (VH) complementarity determining regions (CDRs):
• (i) VH CDR1, said VH CDR1 has a sequence as set forth in the CDR1 sequence of the VH as shown in SEQ ID NO:
• 1, or has a sequence having a substitution, deletion or addition of 1, 2 or 3 amino acids compared to the CDR1 sequence of the VH as shown in SEQ ID NO:
• 1;
• (ii) VH CDR2, said VH CDR2 has a sequence as set forth in the CDR2 sequence of the VH as shown in SEQ ID NO:
• 1, or has a sequence having a substitution, deletion or addition of 1, 2 or 3 amino acids compared to the CDR2 sequence of the VH as shown in SEQ ID NO:
• 1;
• and
• (iii) VH CDR3, said VH CDR3 has a sequence as set forth in the CDR3 sequence of the VH as shown in SEQ ID NO:
• 1, or has a sequence having a substitution, deletion or addition of 1, 2 or 3 amino acids compared to the CDR3 sequence of the VH as shown in SEQ ID NO:
• 1;
• and/or
• (b) the following three light chain variable region (VL) CDRs:
• (iv) VL CDR1, said VL CDR1 has a sequence as set forth in the CDR1 sequence of VL as shown in SEQ ID NO:
• 2, or has a sequence having a substitution, deletion or addition of 1, 2 or 3 amino acids compared to the CDR1 sequence of the VL as shown in SEQ ID NO:
• 2;
• (v) VL CDR2, said VL CDR2 has a sequence as set forth in the CDR2 sequence of the VL as shown in SEQ ID NO:
• 2, or has a sequence having a substitution, deletion or addition of 1, 2 or 3 amino acids compared to the CDR2 sequence of the VL as shown in SEQ ID NO:
• 2;
• and
• (vi) VL CDR3, said VL CDR3 has a sequence as set forth in the CDR3 sequence of the VL as shown in SEQ ID NO:
• 2, or has a sequence having a substitution, deletion or addition of 1, 2 or 3 amino acids compared to the CDR3 sequence of the VL as shown in SEQ ID NO:
• 2;
• wherein, the substitution described in any one of (i)-(vi) is a conservative substitution;
• and
• the CDR1, CDR2 and CDR3 of the heavy chain variable region (VH), and/or the CDR1, CDR2 and CDR3 of the light chain variable region (VL) are defined by Kabat, Chothia or IMGT numbering system;
• and
• the VH and/or VL of the antibody or antigen-binding fragment thereof comprises a framework region (FR) derived from human or mouse.