Salvage Autologous Transplant in Relapsed Multiple Myeloma: Long-Term Follow-Up of the Phase 3 GMMG ReLApsE Trial.

The multicenter, phase III GMMG ReLApsE trial (EudraCT-No:2009-013856-61) randomized relapsed and/or refractory multiple myeloma (RRMM) patients equally to lenalidomide/dexamethasone (LEN/DEX, 25mg days 1-21/40mg weekly, 4-week cycles) re-induction, salvage high dose chemotherapy (sHDCT, melphalan 200mg/m2), autologous stem cell transplantation (ASCT) and LEN maintenance (10mg/day; transplant arm, n=139) versus continuous LEN/DEX (control arm, n=138). Ninety-four percent of patients had received frontline HDCT/ASCT. We report an updated analysis of survival endpoints with a median follow-up of 99 months. Median progression-free survival (PFS) was 20.5 and 19.3 months in the transplant and control arm, respectively (HR 0.98; 95% CI 0.76-1.27; p=0.9). Median overall survival (OS) was 67.1 and 62.7 months (HR 0.89; 95% CI 0.66-1.20; p=0.44). Landmark analyses from sHDCT and the contemporaneous LEN/DEX cycle 5 were performed due to dropout of 29% of patients before sHDCT/ASCT in the transplant arm but did not reveal significant differences in PFS (23.0 vs. 20.3 months; HR 0.91; 95% CI 0.68-1.22; p=0.52) or OS (76.3 vs. 66.0 months; HR 0.8; 95% CI 0.56-1.13; p=0.2). Time to progression after frontline HDCT/ASCT (TTP1) was a prognostic factor but did not predict benefit from sHDCT/ASCT. The GMMG ReLApsE trial does not support use of sHDCT/ASCT in RRMM after frontline HDCT/ASCT. EudraCT-No: 2009-013856-61.