Combination therapy with lenalidomide plus dexamethasone (Rev/Dex) for newly diagnosed myeloma

We report the results of a phase 2 trial using lenalidomide plus dexamethasone (Rev/Dex) as initial therapy for myeloma. Thirty-four patients were enrolled. Lenalidomide was given orally 25 mg daily on days 1 to 21 of a 28-day cycle. Dexamethasone was given orally 40 mg daily on days 1 to 4, 9 to 12, and 17 to 20 of each cycle. Objective response was defined as a decrease in serum monoclonal protein level by 50% or greater and a decrease in urine M protein level by at least 90% or to a level less than 200 mg/24 hours, confirmed by 2 consecutive determinations at least 4 weeks apart. Thirty-one of 34 patients achieved an objective response, including 2 (6%) achieving complete response (CR) and 11 (32%) meeting criteria for both very good partial response and near complete response, resulting in an overall objective response rate of 91%. Of the 3 remaining patients not achieving an objective response, 2 had minor response (MR) and one had stable disease. Forty-seven percent of patients experienced grade III or higher nonhematologic toxicity, most commonly fatigue (15%), muscle weakness (6%), anxiety (6%), pneumonitis (6%), and rash (6%). Rev/Dex is a highly active regimen with manageable side effects in the treatment of newly diagnosed myeloma.