IMbassador250: This phase III trial will test enzalutamide alone and in combination with an anti-PD-L1 antibody (atezolizumab) for the treatment of metastatic, castration-resistant prostate cancer that has failed prior therapyA Phase III, Multicenter, Randomized Study of Atezolizumab (Anti-PD-L1 Antibody) in Combination With Enzalutamide Versus Enzalutamide Alone in Patients With Metastatic Castration-Resistant Prostate Cancer After Failure of an Androgen Synthesis Inhibitor and Failure of, Ineligibility for, or Refusal of a Taxane Regimen

Exclusion

• Prior treatment with enzalutamide or any other newer hormonal androgen receptor inhibitor (e.g., apalutamide, ODM-201)
• Treatment with any approved anti-cancer therapy, including chemotherapy, immunotherapy, radiopharmaceutical or hormonal therapy (with the exception of abiraterone), within 4 weeks prior to initiation of study treatment
• Treatment with abiraterone within 2 weeks prior to study treatment
• Structurally unstable bone lesions suggesting impending fracture
• Known or suspected brain metastasis or active leptomeningeal disease
• Major surgical procedure other than for diagnosis within 4 weeks prior to initiation of study treatment or anticipation of need for a major surgical procedure during the course of the study
• Active or history of autoimmune disease or immune deficiency
• Prior allogeneic stem cell or solid organ transplantation
• History of idiopathic pulmonary fibrosis, organizing pneumonia (e.g., bronchiolitis obliterans), drug-induced pneumonitis, or idiopathic pneumonitis, or evidence of active pneumonitis on screening chest computed tomography (CT) scan
• Positive human immunodeficiency virus (HIV) test, active tuberculosis, active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection
• Prior treatment with cluster of differentiation (CD)137 agonists or immune checkpoint blockade therapies, including anti Cytotoxic T Lymphocyte-Associated 4 (CTLA4), anti-programmed death 1 (PD-1), and anti-PD-L1 therapeutic antibodies
• Treatment with systemic immunostimulatory agents within 4 weeks or five half-lives of the drug, whichever is shorter, prior to initiation of study treatment
• Treatment with systemic immunosuppressive medication within 2 weeks prior to initiation of study
• History of seizure or any condition that may predispose to seizure within 12 months prior to study treatment, including history of unexplained loss of consciousness or transient ischemic attack