Abstract
Patients with classic Hodgkin lymphoma (cHL) that has relapsed after autologous or allogeneic transplant have limited treatment options and a poor prognosis. Immunotherapy with agents that target the PROGRAMMED DEATH 1 (PD-1) receptor have demonstrated clinical activity with durable responses in early-phase clinical trials in this patient population; however, patients with a history of allogeneic stem cell transplantation (SCT) were intentionally excluded from participation in those studies due to concerns for reactivation of graft-versus-host disease (GVHD). We describe the clinical course of two patients with advanced cHL and prior treatment with allogeneic stem cell transplantation (SCT) that were treated with the PD-1 inhibitor pembrolizumab. Both patients had no active graft-versus-host disease (GVHD) at the time initiation of therapy and were maintained on low-dose prednisone. Treatment with pembrolizumab was well tolerated and not associated with reactivation of GVHD. Both patients responded (1 partial, 1 complete) and remain on therapy as of November 30, 2015. This report indicates that immunotherapy targeting the PD-1 pathway can be safely administered to patients with cHL and a history of allogeneic SCT and produce tumor responses. Further studies in this patient population are needed.