[Efficacy and safety of programmed death-1 inhibitor in the treatment of relapsed/refractory classical Hodgkin's lymphoma].

ABSTRACT

Objective: This retrospective, single-center study aimed to evaluate the efficacy and safety of programmed death-1 (PD-1) inhibitors, either as monotherapy or in combination with chemotherapy, in the management of relapse/refractory classical Hodgkin's lymphoma (R/R cHL) . Methods: A total of 35 patients with R/R cHL who received treatment at the Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College from September 2016 to December 2020 were enrolled in this study. Among them, 17 patients received PD-1 inhibitor monotherapy (PD-1 inhibitor group), while 18 patients received a combination of PD-1 inhibitor and chemotherapy (PD-1 inhibitor + chemotherapy group). Clinical data and follow-up information were retrospectively analyzed, and survival analysis was conducted using the Kaplan-Meier method and Cox proportional hazards model. Results: The median age of the 35 patients with R/R cHL was 29 years (range 11-61 years), with 54.3% being male. According to the Ann Arbor staging system, 62.9% of patients presented with advanced (stage Ⅲ/Ⅳ) disease, and 48.6% had extranodal involvement. Before PD-1 inhibitor therapy, the median number of prior lines of therapy was 2 (range 1-3). Objective responses were observed in 28 patients, including 22 complete response (CR) cases, resulting in an overall response rate (ORR) of 80.0% and a CR rate of 62.9%. Specifically, the ORR and CR rates were 64.7% and 58.8%, respectively, in the PD-1 inhibitor group and 94.4% and 66.7%, respectively, in the PD-1 inhibitor + chemotherapy group. Among the 18 patients who underwent sequential autologous hematopoietic stem cell transplantation (auto-HSCT) [13 CR and five partial response (PR) cases], eight patients received PD-1 inhibitor therapy after auto-HSCT as consolidation therapy. All patients maintained a CR status after transplantation, and they exhibited significantly improved progression-free survival (PFS) rates compared with those who did not undergo sequential auto-HSCT (4-year PFS rates 100% vs 53.5% ; P=0.041). The incidence of immune-related adverse events was 29%, with only one patient experiencing grade≥3 adverse reactions, which indicated a favorable safety profile for the treatment approach. Conclusions: PD-1 inhibitor monotherapy demonstrates notable efficacy and sustained response in patients with R/R cHL. PD-1 inhibitors combined with chemotherapy significantly improve response rates. Additionally, for salvage therapy-sensitive patients, consolidation treatment with PD-1 inhibitors after auto-HSCT exhibits the potential for prolonging PFS.