Fig. 1

Clinical trial schema. Patients with metastatic or recurrent head and neck cancer, renal cell carcinoma, or non-small cell lung cancer were randomized to either receive pembrolizumab pre-treatment or no pembrolizumab pre-treatment. Patients were again randomized to receive a single dose of 8 Gy of radiation or five doses of 4 Gy of radiation. Tumor biopsies were obtained at the beginning of the trial as well as 3–10 days following the last dose of RT. Following RT, all patients received 200 mg of pembrolizumab every 3 weeks