Checkpoint inhibition before haploidentical transplantation with posttransplant cyclophosphamide in Hodgkin lymphoma.

We report on 59 Hodgkin lymphoma patients undergoing haploidentical stem cell transplantation (SCT; haplo-SCT) with posttransplant cyclophosphamide (PTCy) as graft-versus-host disease (GVHD) prophylaxis, comparing outcomes based on pretransplant exposure to checkpoint inhibitors (CPIs). Considering pretransplant characteristics, the 2 cohorts (CPI = 29 patients vs no-CPI = 30 patients) were similar, except for the number of prior lines of therapy (6 vs 4; P < .001). With a median follow-up of 26 months (range, 7.5-55 months), by univariate analysis, the 100-day cumulative incidence of grade 2-4 acute GVHD was 41% in the CPI group vs 33% in the no-CPI group (P = .456), whereas the 1-year cumulative incidence of moderate to severe chronic GVHD was 7% vs 8%, respectively (P = .673). In the CPI cohort, the 2-year cumulative incidence of relapse appeared lower compared with the no-CPI cohort (0 vs 20%; P = .054). No differences were observed in terms of overall survival (OS), progression-free survival (PFS), and nonrelapse mortality (NRM) (at 2 years, 77% vs 71% [P = .599], 78% vs 53% [P = .066], and 15% vs 21% [P = .578], respectively). By multivariable analysis, CPI before SCT was an independent protective factor for PFS (hazard ratio [HR], 0.32; P = .037). Stable disease (SD)/progressive disease (PD) was an independent negative prognostic factor for both OS and PFS (HR, 14.3; P < .001 and HR, 14.1; P < .001, respectively) . In conclusion, CPI as a bridge to haplo-SCT seems to improve PFS, with no impact on toxicity profile.