Zimberelimab is a recombinant anti-PD-1 monoclonal antibody derived from human IgG4. In the H-chain, the amino acid residue is substituted at 1 position (S231P). Zimberelimab is produced in CHO cells. Zimberelimab is a glycoprotein (molecular weight: ca. 147,000) composed of 2 H-chains (γ4-chains) consisting of 450 amino acid residues each and 2 L-chains (λ-chains) consisting of 216 amino acid residues each.