Trends in postrelapse survival in classic Hodgkin lymphoma patients after experiencing therapy failure following auto-HCT

Patients with classic Hodgkin lymphoma (cHL) who relapse after autologous hematopoietic cell transplantation (auto-HCT) historically have had poor outcomes. We hypothesized that, post-auto-HCT relapse, overall survival (PR-OS) has improved in recent years as a result of more widespread use of novel therapies and allogeneic HCT (allo-HCT). We conducted a retrospective study in 4 US academic centers, evaluating 215 patients who underwent auto- HCT from 2005 to 2016 and relapsed thereafter. Patients were divided into 2 cohorts based on timing of auto-HCT, 2005 through 2010 (cohort 1; n5118) and 2011 to 2016 (cohort 2; n597), to compare differences in clinical outcomes. The median age and disease status at auto-HCT were similar in cohorts 1 and 2. The proportions of patients who received brentuximab vedotin (Bv; 55% vs 69%; P = .07), checkpoint inhibitors (CPIs; 3% vs 36%; P ≤ .001), and allogeneic-HCT (22%vs 35%, P5 .03) were significantly different between cohorts 1 and 2, respectively. At the 5-year follow-up after auto relapse, 32% and 50% of patients were alive in cohorts 1 and 2, respectively (P = .01). Inmultivariate analysis for PR-OS, cohort 1 vs 2 (hazard ratio [HR], 2.3; 95% confidence interval [CI], 1.14-4.60; P = .01), age at auto-HCT (HR, 1.48; 95% CI, 1.18-1.87; P ≤ .001), and time to relapse from auto-HCT (HR, 0.59; 95% CI, 0.47-74; P ≤ .0001), retained independent prognostic significance for PR-OS. Our study supports the hypothesis that survival of cHL patients after auto-HCT failure has significantly improved in recent years, most likely because of incorporation of novel therapies andmore widespread use of allo-HCT.