UCDCC#272: IL-2, Radiotherapy, and Pembrolizumab in Patients Refractory to Checkpoint Blockade

This is a phase I/II study that will evaluate the safety and toxicity of this combinatorial approach. Eligible patients \>18 years of age with histologically proven metastatic NSCLC, melanoma, RCC, or HNSCC who have failed PD-1 / PD-L1 checkpoint blockade therapy will be enrolled. Patients must have a candidate treatment lesion (subcutaneous, nodal, or visceral) accessible and safe for radiotherapy and serial intralesional injections as specified by the protocol. They must also have at least one target lesion (distinct from treatment lesion and outside of treatment lesion radiation field) evaluable for response by RECIST. This study will consist of a phase I dose escalation using a standard 3+3 design to determine safety and MTD of intralesional IL-2 which will be dose escalated in conjunction with standard fixed doses of RT and Pembrolizumab. At the MTD there will be a phase II dose expansion which will incorporate a simon-two stage design to assess efficacy and safety. Patients will receive pembrolizumab and intralesional IL-2 in combination with hypofractionated radiotherapy.