Melphalan, Prednisone, and Lenalidomide Treatment for Newly Diagnosed Myeloma: A Report From the GIMEMA—Italian Multiple Myeloma Network

Lenalidomide has shown significant antimyeloma activity in clinical studies. Oral melphalan, prednisone, and thalidomide have been regarded as the standard of care in elderly multiple myeloma patients. We assessed dosing, efficacy, and safety of melphalan, prednisone, and lenalidomide (MPR) in newly diagnosed elderly myeloma patients. Oral melphalan was administered in doses ranging from 0.18 to 0.25 mg/kg on days 1 to 4, prednisone at a 2-mg/kg dose on days 1 to 4, and lenalidomide at doses ranging from 5 to 10 mg on days 1 to 21, every 28 days for nine cycles, followed by maintenance therapy with lenalidomide alone. Aspirin was given as a prophylaxis for thrombosis. Fifty-four patients were enrolled and evaluated after completing the assigned treatment schedule. The maximum tolerated dose was defined as 0.18 mg/kg melphalan and 10 mg lenalidomide. With these doses, 81% of patients achieved at least a partial response, 47.6% achieved a very good partial response, and 23.8% achieved a complete immunofixation-negative response. In all patients, 1-year event-free and overall survival rates were 92% and 100%, respectively. At the maximum tolerated dose, grade 3 adverse events included neutropenia (38.1%), thrombocytopenia (14.2%), febrile neutropenia (9.5%), vasculitis (9.5%), and thromboembolism (4.8%); grade 4 adverse events were neutropenia (14.2%) and thrombocytopenia (9.5%). Oral MPR therapy is a promising first-line treatment for elderly myeloma patients. Hematologic adverse events were frequent but manageable. A low incidence of nonhematologic adverse events was noted. Aspirin appears to provide adequate antithrombosis prophylaxis.