Efficacy of post-transplant brentuximab vedotin maintenance by pre-transplant disease status in relapsed/refractory classic Hodgkin lymphoma.

Patients with classic Hodgkin lymphoma (cHL) with primary refractory disease, early relapse, or extranodal disease have a higher risk of relapse after salvage therapy and autologous stem cell transplant (ASCT). Post-ASCT brentuximab vedotin (BV) maintenance improved progression-free survival (PFS) in high-risk relapsed/refractory (R/R) cHL in the AETHERA trial, but subgroup analysis suggested that the benefit in patients transplanted in complete metabolic response (CMR) is unclear. In a large international real-world cohort, we assessed the efficacy of BV maintenance stratified by pre-ASCT metabolic response and by the number of clinical risk factors as defined in the AETHERA trial. Adult patients with R/R cHL who met AETHERA risk criteria were included. Utilizing propensity score analyses, PFS and OS were assessed overall and in subgroups of CMR (442 pts) and partial metabolic response (PMR, 249 pts). We observed that post-ASCT BV maintenance was associated with significantly higher PFS in the subgroup with PMR (5-year PFS: 59.6% vs 43.3% HR = 0.52, CI95: 0.33-0.82; p = 0.007). In the subgroup of patients with CMR, BV maintenance did not significantly improve PFS (5-year PFS: 75.8% vs 62.3% HR = 0.88, CI95: 0.59-1.32; p = 0.29). However, when focusing on patients with CMR treated post-FDA approval of BV, there was a significant PFS benefit observed in those treated with BV maintenance vs. not (5-year PFS: 81.2% vs 55.2% HR = 0.40, CI95: 0.22-0.72; p = 0.003). Overall, BV maintenance after ASCT remains an important therapy for high-risk R/R cHL patients, especially for those in PMR or those in CMR.