Allogeneic stem cell transplantation for relapsed and refractory Hodgkin lymphoma after treatment with checkpoint inhibitors: Real-world experience of a single center

Background.Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a current treatment option for patients with refractory/relapsed Hodgkin lymphoma (R/R HL), including those whose disease has failed to respond to checkpoint inhibitor (CPI) treatment.Objectives.To evaluate the outcomes of alloHSCT after CPI therapy in R/R HL. Materials and methods.We performed a retrospective single-center analysis of 8 patients (median age: 30.9 years (range: 21.6-50. 1 years); 62.5% male) with R/R HL who had undergone alloHSCT after CPI therapy in Poland. Results.At the time of alloHSCT, 2 patients (25%) were in complete remission (CR), 4 (50%) were in partial remission (PR), and 2 (25%) had stable disease.Haploidentical related donors were used in 6 patients (75%) and matched unrelated donors in 2 patients (25%).Reduced-intensity conditioning based on the Baltimore platform was applied in 6 patients (75%), and busulfan/fludarabine conditioning was used in 2 patients (25%).Acute graft-versus-host disease (GVHD) occurred in 2 patients (25%), including 1 case of grade III disease (12.5%), while chronic GVHD developed in 4 patients (50%), with moderate-to-severe disease in 2 patients (25%).Two patients (25%) died from transplant-related causes.At a median follow-up of 13.4 months, 5 patients (62.5%) remained in CR.Median progression-free survival was 22.6 months, and median overall survival (OS) was not reached. Conclusions.To our knowledge, this is the largest Polish single-center analysis published to date.In our cohort, alloHSCT after CPI therapy was feasible with acceptable safety.However, because of the small sample size, retrospective design, and relatively short follow-up, no definitive conclusions regarding long-term efficacy or safety can be drawn.Additional prospective studies are needed for further clarification.