Long-term follow-up in the phase III QuiRedex trial indicates continued benefit of lenalidomide (Revlimid)/dexamethasone vs observation in preventing disease progression in patients with high-risk smoldering multiple myeloma, as reported by Maria-Victoria Mateos, PhD, of Instituto de Biologia Molecular y Celular del Cancer, Salamanca, and colleagues in The Lancet Oncology.
In the open-label trial, conducted at 19 sites in Spain and 3 sites in Portugal, 119 patients (constituting the per-protocol population for efficacy analysis) were randomized between November 2007 and June 2010 to receive induction lenalidomide/dexamethasone followed by lenalidomide maintenance and dexamethasone at biologic progression during maintenance (n = 57) or observation (n = 62). At the time of first analysis in 2013, at a median follow-up of 45 months, median time to progression to symptomatic disease was not reached vs 21 months (hazard ratio [HR] = 0.18, P < .0001), and 3-year overall survival was 94% vs 80% (HR = 0.31, P = .03).
In the current analysis, at median follow-up for surviving patients of 75 months, median time to disease progression was not reached vs 23 months (HR = 0.24, P < .0001), with disease progression occurring in 39% vs 86% of patients. Median overall survival from the time of study entry had not been reached in either group (HR = 0.43, P = .024). There was no significant difference between the groups in survival among patients who received subsequent treatment at disease progression (HR = 1.34, P = .50). Overall, 39% and 85% of patients received antimyeloma treatment after disease progression. Second primary malignancies occurred in 10% of the lenalidomide/dexamethasone group vs 2% of the observation group (P = .070).
The investigators concluded: “This study is, to our knowledge, the first randomised trial in which early treatment has been assessed in selected patients with high-risk smouldering multiple myeloma. Positive results from ongoing trials would support the use of early treatment for patients with high-risk disease in the near future.”
The study was funded by PETHEMA (Spanish Program for the Treatment of Hematologic Diseases).■