Phase II study of pembrolizumab (MK-3475) for relapsed/refractory classical Hodgkin Lymphoma (r/r cHL): keynote-087

Background The prognosis is poor for patients with cHL who relapse after autologous stem-cell transplant (auto-SCT) or progress after brentuximab vedotin (BV) therapy. cHL frequently harbors genetic amplification at 9p24.1, which leads to overexpression of PD-L1 and PD-L2 on the tumor cell surface. This suggests that cHL may have a genetically determined dependence on the PD-1 pathway for survival. Pembrolizumab is a humanized monoclonal antibody against PD-1 that is designed to block the interaction of PD-1 with its ligands PD-L1 and PD-L2. Based on the frequent expression of the ligands on cHL, we sought to evaluate the safety and efficacy of pembrolizumab for R/R cHL. In a Phase I study, pembrolizumab displayed high activity in cHL, with an overall response rate of 65% and complete response rate of 20% [1]. The present Phase II study was undertaken to extend those findings in a larger cohort.