Testing Cabozantinib With or Without Atezolizumab in Patients With Advanced Papillary Kidney Cancer, PAPMET2 Trial

PRIMARY OBJECTIVE: I. To compare progression-free survival in participants with metastatic papillary renal cell carcinoma (mPRCC) randomized to cabozantinib (cabozantinib S-malate) with atezolizumab versus cabozantinib alone. SECONDARY OBJECTIVES: I. To compare overall survival in participants with mPRCC randomized to cabozantinib with atezolizumab versus cabozantinib alone. II. To compare Response Evaluation Criteria in Solid Tumors (RECIST) objective response rate (confirmed and unconfirmed, complete and partial response) in participants with mPRCC randomized to cabozantinib with atezolizumab versus cabozantinib alone. III. To evaluate the quantitative and qualitive adverse events observed in each treatment arm. BANKING OBJECTIVE: I. To bank biospecimens for future correlative studies. OUTLINE: Patients are randomized to 1 of 2 arms. ARM I: Patients receive cabozantinib S-malate orally (PO) once daily (QD) on days 1-21 of each cycle. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. Patients also undergo computed tomography (CT) or magnetic resonance imaging (MRI) and blood and urine sample collection throughout the trial. Patients may also undergo bone scan throughout the trial. ARM II: Patients receive cabozantinib S-malate PO QD on days 1-21 and atezolizumab intravenously (IV) over 30-60 minutes on day 1 of each cycle. Cycles repeat every 21 days in the absence of disease progression or unacceptable toxicity. Patients also undergo CT scan or MRI and blood and urine sample collection throughout the trial. Patients may also undergo bone scan throughout the trial. After completion of study treatment, patients are followed up every 3 months for 2 years and then every 6 months for up to 5 years.