Atezolizumab is a monoclonal antibody medication used to treat urothelial carcinoma, non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), hepatocellular carcinoma and alveolar soft part sarcoma, but discontinued for use in triple-negative breast cancer (TNBC).

The most common side effects when used on its own include tiredness, reduced appetite, nausea, vomiting, cough, difficulty breathing, diarrhea, rash, fever, pain in the back, joints, muscles and bones, weakness, itching and urinary tract infection. The most common side effects when used with other cancer medicines include peripheral neuropathy (nerve damage in the hands and feet), nausea, anemia (low red blood cell counts), neutropenia (low white blood cell counts), thrombocytopenia (low platelet counts), rash, tiredness, constipation, reduced appetite, diarrhea, and cough.

Atezolizumab was the first PD-L1 inhibitor approved by the U.S. for bladder cancer. Food and Drug Administration (FDA).