Sitravatinib Plus Nivolumab in Patients Undergoing Nephrectomy for Locally Advanced Clear Cell Renal Cell Carcinoma

Sitravatinib is an immunomodulatory tyrosine kinase inhibitor that can augment responses when combined with programmed death-1 (PD-1) inhibitors such as nivolumab. We report a phase 2 study of neoadjuvant sitravatinib in combination with nivolumab in patients with locally advanced clear cell renal cell carcinoma (ccRCC) prior to curative nephrectomy (NCT03680521). The primary endpoint was objective response rate (ORR) prior to surgery with a null hypothesis ORR = 5% and the alternative hypothesis set at ORR = 30%. Secondary endpoints included correlative immune effects and disease-free survival (DFS). Twenty patients were evaluable for safety and 17 for efficacy. The ORR was 11.8%, and 24-month DFS probability was 88·0% (95% CI 61.0 to 97.0). There were no grade 4/5 treatment-related adverse events. Correlative blood and tissue analyses showed changes in the tumour microenvironment resulting in an immunologically active tumour by the time of surgery. These data suggest that short-term neoadjuvant sitravatinib and nivolumab does not substantially increase ORR but can modulate the immune microenvironment and yield high DFS probabilities in patients with locally advanced ccRCC. Expression profiling of patient data before treatment and after treatment with single drug and drug combination