Lenalidomide in combination with dexamethasone for the treatment of multiple myeloma after one prior therapy.

Purpose: Lenalidomide (CC-5013, Revlimid; Celgene Corporation, Summit, NJ), a thalidomide analogue, was granted approval by the U.S. Food and Drug Administration (FDA) on June 29, 2006, for use in combination with dexamethasone in patients with multiple myeloma (MM) who have received at least one prior therapy. The FDA approved lenalidomide with a restricted distribution program, RevAssist.

Experimental Design: In two randomized, double-blind, multicenter studies, the combination of lenalidomide and dexamethasone (LD) was compared with placebo and dexamethasone (PD) in patients with MM who had received at least one prior therapy. The primary endpoint was time to progression (TTP).

Results: Following a prespecified interim analysis of TTP, an independent data-monitoring committee advised the sponsor to halt the two studies. For both studies, the interim analysis for efficacy revealed a statistically significant longer TTP with LD than with PD. The most clinically relevant grade 3 and 4 adverse events that occurred more frequently in the LD arm were neutropenia, thrombocytopenia, deep vein thrombosis, pulmonary embolism, and atrial fibrillation. Thrombotic or thromboembolic events, including deep vein thrombosis, pulmonary embolism, thrombosis, and intracranial venous sinus thrombosis were reported more frequently in patients treated with LD than with PD.

Conclusions: The FDA approved lenalidomide based on interim results from two multicenter, placebo-controlled, randomized trials comparing the combination of LD with PD that revealed a longer TTP with LD than with PD. The major toxicity observed during these trials was myelosuppression. The serious toxicities included thromboembolic events. Lenalidomide is only available under the RevAssist Program.