A bispecific antibody directed against the human negative immunoregulatory checkpoint receptors programmed cell death protein 1 (PD-1; PD1; PDCD1; CD279; Programmed Death 1) and lymphocyte activation gene 3 protein (LAG-3; LAG3; CD223), with potential immune checkpoint inhibitory and antineoplastic activities. Upon administration, anti-PD-1/anti-LAG-3 bispecific antibody RO7247669 targets and binds to both PD-1 and LAG-3 expressed on T-cells and inhibits the PD-1- and LAG-3-mediated downregulation of T-cell activation and proliferation. This may lead to cytotoxic T-lymphocyte (CTL)-mediated immune response against tumor cells. PD-1 and LAG-3 play key roles in suppressing T-cell activation and proliferation.