Study of Entinostat With Nivolumab Plus Ipilimumab in Previously Treated Renal Cell Carcinoma

This is a Phase II, open-label, safety, pharmacodynamic and efficacy study of entinostat in combination with nivolumab and ipilimumab in subjects with metastatic renal cell carcinoma (RCC) who have progressed on ipilimumab + nivolumab regimen. Prior to Phase II, a safety lead-in will be conducted to establish the RP2D of entinostat when used in combination with ipilimumab + nivolumab. Subjects will initially be treated with the combination of oral entinostat and intravenous (IV) nivolumab plus ipilimumab. Entinostat will be dosed weekly, and nivolumab and ipilimumab will be dosed every 3 weeks, for a total of four, 3-week cycles. Following these first four cycles, entinostat will continue to be administered weekly in combination with nivolumab every 4 weeks or every 2 weeks based on subject tolerance (ipilimumab will be discontinued), with treatment continued until disease progression or prohibitive toxicity. Anti-tumor activity will be assessed by radiological tumor assessments conducted at baseline and every 6 weeks thereafter using RECIST version 1.1.