Randomized Phase 2 Trial of Retreatment With Pomalidomide or Lenalidomide With Dexamethasone for Patients With Relapsed Myeloma

PRIMARY OBJECTIVES: I. To assess the confirmed response rate of the combination of lenalidomide and dexamethasone in patients with relapsed myeloma who have previously become refractory to lenalidomide. (Arm A) II. To assess the confirmed response rate of the combination of pomalidomide and dexamethasone in patients with relapsed myeloma who have previously become refractory to lenalidomide. (Arm B) SECONDARY OBJECTIVES: I. To assess the toxicity in each arm in patients with relapsed myeloma who have previously received lenalidomide. II. To assess the response rates with pomalidomide and dexamethasone in patients relapsing on lenalidomide and dexamethasone. (Arm A) III. To assess time to progression and overall survival with each approach. OUTLINE: Patients are randomized to 1 of 2 treatment arms. ARM A: Patients receive lenalidomide orally (PO) daily on days 1-21 and dexamethasone PO on days 1, 8, 15, and 22. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. Patients experiencing progressive disease may crossover to arm B. ARM B: Patients receive pomalidomide PO daily on days 1-21 and dexamethasone as in arm A. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up periodically.