Inclusion Criteria:

          -  Measurable disease of MM as defined by at least ONE of the following:

               1. Serum monoclonal protein (SPEP) ≥1 g/dL

               2. Urine M-protein ≥200 mg/24 hrs

               3. Serum free light chain (SFLC): involved FLC ≥10 mg/dL (≥100 mg/L) AND abnormal
                  kappa to lambda serum free light chain ratio

          -  Relapsed or relapsed and refractory MM after receiving at least 2 previous therapies,
             including an immunomodulator and bortezomib and had either no response or documented
             disease progression (according to IMWG criteria) to the most recent treatment regimen

          -  Adequate hematologic, hepatic, and renal function

          -  ECOG performance status of 0-2

        Inclusion Criteria for Phase 2 Sub-study Cohort:

          -  Must meet all inclusion criteria defined in main study and in addition the following
             criteria must be met:

          -  Subject must have received a regimen containing carfilzomib in combination with
             dexamethasone as their most recent line of therapy and have:

               1. Achieved less than a partial response (<PR) following at least 4 cycles and are
                  without evidence of progression disease (PD).

                  OR

               2. Disease progression following an initial confirmed response of MR or better to
                  the combination (according to IMWG response criteria).

        Exclusion Criteria:

          -  Subject must not have primary refractory disease

          -  Plasma cell leukemia, primary amyloidosis or POEMS syndrome

          -  Unable to swallow capsules or disease significantly affecting gastrointestinal
             function

          -  Requires anti-coagulation with warfarin or a vitamin K antagonist

          -  Requires treatment with strong CYP3A inhibitors

        Exclusion Criteria for Phase 2 Sub-study Cohort:

          -  Must not meet any exclusion criteria defined in main study except for exclusion
             criteria "Subject must not have primary refractory disease" which is related to prior
             carfilzomib