Immune checkpoint inhibitors (ICI) are promising therapeutic agents for relapsed or refractory classical Hodgkin's lymphoma (RRcHL). This retrospective study evaluated patients with RRcHL registered in the clinical research program Tohoku-Hematology-Forum-26, between 2016 and 2020, and treated with ICI in 14 centers in Northeast Japan. We analyzed the usage, efficacy, and safety of ICI therapy (ICIT). Among a total of 27 patients with RRcHL, 21 and nine were treated with nivolumab and/or pembrolizumab, respectively. The best response was complete response (CR), partial response (PR), stable disease (SD), and progressive disease in 11 (40.8%), seven (25.9%), eight (29.6%), and one (3.7%) patient, respectively. In all patients undergoing ICIT, the 2-year progression-free survival and 2-year overall survival (OS) were 48.6% and 87.4%, respectively. The 2-year OS for patients with CR, PR, and SD were 100%, 68.6%, and 87.5%, respectively. A total of 36 events of immune-related adverse events (irAEs) or immune-related like adverse events (irlAEs) were observed in 19 of the 27 patients (70.4%). Two thirds of these irAEs or irlAEs were grade 1-2 and controllable. During the observation period, ICIT was discontinued in 22 of 27 (81.4%) patients due to CR, inadequate response, irAE and patient circumstances in five (22.7%), seven (31.8%), eight (36.4%) and two patients (9.1%), respectively. Therapy-related mortality-associated irAE were observed in only one patient during ICIT. These results suggest that ICIT for RRcHL is effective and safe in real-world settings. The optimal timing of induction and duration of ICIT remains to be established.
Keywords: classical Hodgkin’s lymphoma; immune checkpoint inhibitors; real-world setting; relapsing and refractory cHL.