atezolizumab + pembrolizumab

Atezolizumab + pembrolizumab is an investigational combination of two immune checkpoint inhibitor monoclonal antibodies, each targeting a different component of the PD-1/PD-L1 pathway. Atezolizumab is a humanized IgG1 monoclonal antibody that binds to programmed cell death-ligand 1 (PD-L1), blocking its interaction with PD-1 and B7.1 receptors, thereby enhancing T-cell mediated anti-tumor responses. Pembrolizumab is a humanized IgG4-kappa monoclonal antibody that targets programmed cell death protein 1 (PD-1) on T cells, preventing its interaction with PD-L1 and PD-L2 ligands and releasing inhibition of the immune response against tumor cells[2][6][5]. Both drugs are approved individually for multiple cancers but their use in direct combination as "atezolizumab + pembrolizumab" remains investigational.