A Proof of Principle Study of Pembrolizumab With SBRT in TKI mRCC Patients

200mg given intravenously over 30 minutes day 1 of every 3 week cycle until progression as per immune related response criteria

Dose and duration dependent on body site. In Arm A: SBRT given at the time of progression on pembrolizumab. In Arm B: SBRT given before the 2nd course of pembrolizumab.