Atezolizumab

Atezolizumab is a humanized monoclonal antibody that targets programmed death-ligand 1 (PD-L1). By blocking PD-L1, it prevents its interaction with the receptors PD-1 and B7.1, thereby enhancing T-cell–mediated immune responses against tumor cells. The drug is developed by Genentech and marketed under the brand name Tecentriq. It has been approved in multiple countries for the treatment of various solid tumors, initially in metastatic urothelial carcinoma and non-small cell lung cancer, with subsequent approvals in other indications and in combination regimens.

Commonly treated conditions include urothelial carcinoma (bladder cancer) and non-small cell lung cancer (NSCLC). In addition, atezolizumab has been approved for extensive-stage small cell lung cancer (SCLC) when given with chemotherapy, and in combination with bevacizumab for unresectable hepatocellular carcinoma (HCC). Regulatory approvals vary by country and over time, reflecting evolving evidence from clinical trials.

Administration and dosing are by intravenous infusion. In many indications, a typical dose is 1200 mg every 3 weeks, given until disease progression or unacceptable toxicity; combination regimens may use different schedules and partner agents. Safety concerns center on immune-related adverse events, including pneumonitis, colitis, hepatitis, endocrinopathies, and infusion-related reactions. These risks require monitoring and prompt management, particularly in patients with underlying autoimmune conditions or those receiving concomitant therapies.

Pharmacologically, atezolizumab is a long-acting immunotherapy agent whose effects reflect modulation of the tumor immune microenvironment. It remains part of ongoing research across tumor types and treatment combinations.