Brentuximab vedotin (BV) consolidation post-autologous stem cell transplant (ASCT) in patients (pts) with Hodgkin lymphoma (HL) at risk of residual disease: Number needed to treat (NNT) analysis.

20 Background: AETHERA (NCT01100502) is a randomized Phase 3 study of BV and best supportive care (BSC) vs placebo (PBO) and BSC in the treatment of pts at risk of residual HL post-ASCT. BV consolidation therapy post-ASCT significantly improved progression-free survival (PFS) by independent review vs PBO (HR = 0.57, P = 0.001) and was FDA approved. Most common grade ≥ 3 adverse events were neutropenia (29% BV vs 10% PBO) and peripheral sensory neuropathy (10% vs 1%). The aim of this study was to determine the NNT with BV to avoid 1 additional event, disease progression/death.

METHODS: The NNT with BV was calculated as the inverse of the absolute risk reduction (ARR); ARR was the PFS event rate per investigator (INV) assessment in the PBO arm minus the event rate in the BV arm of the AETHERA trial. The AETHERA trial recruited pts ≥ 18 yrs at risk of residual HL post-ASCT defined by ≥ 1 of: history of refractory HL; relapse/progression < 12 months after frontline therapy; extranodal involvement at time of pre-ASCT relapse. Pts were randomized to receive BV 1.8 mg/kg or PBO on day 1 of each 21-day cycle, for up to 16 cycles/disease progression.

RESULTS: 329 pts (median age 32 yrs [range 18-76]; 53% male) received BV (n = 165) or PBO (n = 164). Fewer PFS events per INV analysis were experienced by pts in the BV arm vs PBO arm. The NNT with BV to prevent a disease progression/death ranged from 4.08 (95% CI 2.94, 6.96) to 7.79 pts (95% CI 5.05, 16.4) over 48 months (Table). At 24 months (time majority of pts have progressed post-ASCT), the NNT to prevent a disease progression/death was 4.92 pts (95% CI 3.29, 10.39).

CONCLUSIONS: AETHERA data suggest that, at various time points, 1 in every 5-8 pts treated with BV consolidation therapy will benefit by avoiding disease progression/death. This further demonstrates BV's clinical benefit in the post-ASCT consolidation setting.

CLINICAL TRIAL INFORMATION: NCT01100502. [Table: see text].