Continuous lenalidomide treatment for newly diagnosed multiple myeloma.

BACKGROUND: Lenalidomide has tumoricidal and immunomodulatory activity against multiple myeloma. This double-blind, multicenter, randomized study compared melphalan-prednisone-lenalidomide induction followed by lenalidomide maintenance (MPR-R) with melphalan-prednisone-lenalidomide (MPR) or melphalan-prednisone (MP) followed by placebo in patients 65 years of age or older with newly diagnosed multiple myeloma.

METHODS: We randomly assigned patients who were ineligible for transplantation to receive MPR-R (nine 4-week cycles of MPR followed by lenalidomide maintenance therapy until a relapse or disease progression occurred [152 patients]) or to receive MPR (153 patients) or MP (154 patients) without maintenance therapy. The primary end point was progression-free survival.

RESULTS: The median follow-up period was 30 months. The median progression-free survival was significantly longer with MPR-R (31 months) than with MPR (14 months; hazard ratio, 0.49; P<0.001) or MP (13 months; hazard ratio, 0.40; P<0.001). Response rates were superior with MPR-R and MPR (77% and 68%, respectively, vs. 50% with MP; P<0.001 and P=0.002, respectively, for the comparison with MP). The progression-free survival benefit associated with MPR-R was noted in patients 65 to 75 years of age but not in those older than 75 years of age (P=0.001 for treatment-by-age interaction). After induction therapy, a landmark analysis showed a 66% reduction in the rate of progression with MPR-R (hazard ratio for the comparison with MPR, 0.34; P<0.001) that was age-independent. During induction therapy, the most frequent adverse events were hematologic; grade 4 neutropenia was reported in 35%, 32%, and 8% of the patients in the MPR-R, MPR, and MP groups, respectively. The 3-year rate of second primary tumors was 7% with MPR-R, 7% with MPR, and 3% with MP.

CONCLUSIONS: MPR-R significantly prolonged progression-free survival in patients with newly diagnosed multiple myeloma who were ineligible for transplantation, with the greatest benefit observed in patients 65 to 75 years of age. (Funded by Celgene; MM-015 ClinicalTrials.gov number, NCT00405756.).