Overall responses with coordinated pembrolizumab and high dose IL-2 (5-in-a-row schedule) for therapy of metastatic clear cell renal cancer: A single center, single arm trial.

657Background: Ligation of IL-2 receptor or blockade of PD-1 receptor may change lymphocytes to induce regression of cancers with diverse histology or site of origin. Single agent objective response rates of 14-25% have been reported for IL-2 therapy of metastatic clear cell RCC (ccRCC). A response rate of 33% was observed in pembrolizumab treated ccRCC patients. Nivolumab treated ccRCC patients were observed to have early intratumoral migration of lymphocytes. A case report of IL-2 induced major regression right after no change on nivolumab therapy suggested that combining the two means of lymphocyte stimulation could be effective. Other trials combining IL-2 receptor agonists (NKTR-214) and PD-1 blockade have also reported regression of ccRCC. Distinctive attributes of high dose IL-2 therapy are the required inpatient stay and the durability of the complete responses. Methods: This single-institution, single arm study addresses the safety and feasibility of the combination of IL-2 and pembrolizumab in t...