rituximab + atezolizumab + polatuzumab vedotin

**rituximab + atezolizumab + polatuzumab vedotin** is an experimental combination regimen comprising three distinct monoclonal antibody-based therapeutics, each with different mechanisms of action: - **Rituximab** is an anti-CD20 monoclonal antibody that induces the depletion of CD20-positive B cells through mechanisms such as antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and direct induction of apoptosis. - **Atezolizumab** is an anti-PD-L1 (programmed death-ligand 1) monoclonal antibody (also known as a "checkpoint inhibitor") that blocks the PD-L1/PD-1 interaction, enabling T cell-mediated immune responses against tumor cells. - **Polatuzumab vedotin** is an antibody-drug conjugate targeting CD79b on B cells, delivering the cytotoxic agent monomethyl auristatin E (MMAE) via a cleavable linker. After internalization, MMAE inhibits cell division by binding tubulin, leading to apoptosis of the targeted B cell[1][2][4]. This combination aims to leverage direct B-cell killing, immune system activation, and delivery of cytotoxic agents for synergistic antitumor efficacy, particularly in B-cell malignancies such as diffuse large B-cell lymphoma (DLBCL).