Inclusion Criteria:

- Participants must have histologically documented multiple myeloma which is relapsing
or resistant after stem cell transplantation, or when other conventional therapies
have failed or are contraindicated

- Serum creatinine < 3.0 mg/dL OR calculated creatinine clearance >15 mL/min calculated
or measured clearance is ≥15 mL/min

- ANC > 1000/mm3 (may be supported with growth factors)

- Platelet count > 30,000/mm3 (may receive transfusion)

- Female participant of child-bearing potential has agreed to use dual methods of
contraception for the duration of the study

- Male participant has agreed to use a barrier method of contraception if sexually
active with a female of child-bearing potential

- Patients must have signed and IRB-approved written informed consent form and
demonstrate willingness to meet follow-up schedule and study procedure obligations

Exclusion Criteria:

- Active infection requiring systemic treatment

- Requires concomitant use of approved or investigative anticancer therapeutic
treatment with activity against multiple myeloma, other than dexamethasone

- Concomitant use of other investigative agents (e.g., antibiotics or antiemetics)

- Pregnant or breast-feeding