ENDURANCE: A phase III trial of continuous vs fixed-duration lenalidomide maintenance in NDMM

Results from the randomized, open-label, phase III ENDURANCE trial (NCT01863550), evaluating continuous (n = 260) vs 2-year fixed-duration (n = 256) lenalidomide maintenance in patients with standard-risk newly diagnosed multiple myeloma (NDMM) not undergoing up-front autologous stem-cell transplantation (ASCT) were published in The New England Journal of Medicine by Kumar et al. Patients had received induction therapy with carfilzomib, lenalidomide, and dexamethasone (KRd) or bortezomib, lenalidomide, and dexamethasone (VRd). The primary endpoint was overall survival (OS).

Key data: At a median follow-up of 86 months, 7-year OS was 68.6% with continuous vs 69.0% with fixed-duration lenalidomide (difference, −0.4 percentage points; 95% confidence interval [CI], −9.0 to 8.3; p = 0.93). Median progression-free survival (PFS) was 42.5 vs 38.9 months, respectively, and 7-year PFS was 36.1% vs 29.7% (difference, 6.4 percentage points; 95% CI, −2.6 to 15.4). Grade ≥3 nonhematologic adverse events (AEs) occurred in 48.2% vs 31.5% of patients, respectively. The 5-year cumulative incidence of second primary cancers, excluding nonmelanoma skin cancer, was 11.2% vs 8.3%, respectively.

Key learning: Continuous lenalidomide maintenance did not improve OS compared with 2-year fixed-duration maintenance in patients with standard-risk NDMM, while Grade ≥3 nonhematologic AEs occurred more frequently with continuous treatment.