Ixazomib Plus Pomalidomide and Dexamethasone in Treating Patients With Relapsed or Relapsed/Refractory Multiple Myeloma

PRIMARY OBJECTIVES: I. To determine the recommended phase II dose (RP2D) of MLN9708 (ixazomib), when given in combination with pomalidomide and dexamethasone, in patients with relapsed or relapsed/refractory multiple myeloma. (Phase I) II. To estimate the response rate and to evaluate the antitumor activity of the three drug combination: MLN9708 (at the RP2D), pomalidomide and dexamethasone, in patients with relapsed or relapsed/refractory multiple myeloma. (Phase II) SECONDARY OBJECTIVES: I. To evaluate the safety of MLN9708 at each dose level when given as part of a three drug combination by assessing the following: type, frequency, severity, attribution, time course and duration of adverse events; and clinical laboratory tests at various points in the study. (Phase I) II. To characterize and evaluate toxicities, including type, frequency, severity, attribution, time course and duration, at the RP2D, for the three drug combination. (Phase II) III. To obtain estimates of response duration, depth of response, clinical benefit response, and survival (overall and progression-free), at the RP2D, for the three drug combination. (Phase II) OUTLINE: This is a phase I, dose-escalation study of ixazomib followed by a phase II study. Patients receive ixazomib orally (PO) on days 1, 8, and 15; dexamethasone PO on days 1, 8, 15, and 22; and pomalidomide PO on days 1-21. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 3 months for 2 years.