Inclusion Criteria:

- Age >/=18 years at the time of informed consent

- Relapsed or refractory multiple myeloma that was treated with or was considered
inappropriate for treatment with bortezomib and an IMiD drug (including an analogue).

- ECOG Performance Status
- Corrected calcium <10.6 mg/dL

Exclusion Criteria:

- Candidates for stem cell transplantation willing to undergo transplantation.
(Subjects who are candidates for stem cell transplantation, but are not willing to
undergo transplant will be eligible for the study.)

- Autologous stem cell transplantation <3 months post transplant.

- Prior allogeneic stem cell transplantation.

- Non secretory myeloma.

- Plasma cell leukemia (>2000/uL circulating plasma cells by standard cell counting
differential), hyperleukocytosis (white blood cells >100,000/uL, clinical evidence of
hyperviscosity syndrome, POEMS (polyneuropathy, organomegaly, endocrinopathy,
monoclonal gammopathy, and skin changes syndrome), or primary systemic amyloidosis.

- Subjects who cannot undergo a brain MRI study.

- Clinically significant (as determined by the Investigator) 12 lead electrocardiogram
(ECG) abnormalities, including QTc prolongation (>450 ms in males; >470 ms in
females).