A Study of Melphalan Flufenamide (Melflufen)-Dex or Pomalidomide-dex for RRMM Patients Refractory to Lenalidomide

Inclusion Criteria

• •1. Male or female, age 18 years or older
• •2. A prior diagnosis of multiple myeloma with documented disease progression requiring further treatment at time of screening
• •3. Measurable disease defined as any of the following:
• •* Serum monoclonal protein ≥ 0.5 g/dL by protein electrophoresis.
• •* ≥ 200 mg/24 hours of monoclonal protein in the urine on 24-hour electrophoresis
• •* Serum free light chain ≥ 10 mg/dL AND abnormal serum kappa to lambda free light chain ratio
• •4. Received 2-4 prior lines of therapy, including lenalidomide and a PI, either sequential or in the same line, and is refractory (relapsed and refractory or refractory) to both the last line of therapy and to lenalidomide (≥ 10 mg) administered within 18 months prior to randomization. Refractory to lenalidomide is defined as progression while on lenalidomide therapy or within 60 days of last dose, following at least 2 cycles of lenalidomide with at least 14 doses of lenalidomide per cycle.
• •5. Life expectancy of ≥ 6 months
• •6. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2.
• •7. Females of child bearing potential (FCBP) must have a negative serum or urine pregnancy test prior to start of treatment. Participants must agree to ongoing pregnancy testing. All patients must be willing to comply with all requirements of the USA pomalidomide Risk Evaluation and Mitigation Strategy (REMS) program or the pomalidomide Pregnancy Prevention Plan (PPP).
• •8. Ability to understand the purpose and risks of the study and provide signed and dated informed consent.
• •9. 12-lead Electrocardiogram (ECG) with QT interval calculated by Fridericia Formula (QTcF) interval of ≤ 470 msec Fridericia Formula.
• •10. The following laboratory results must be met during screening and also immediately before study drug administration on Cycle 1 Day 1:
• •* Absolute neutrophil count (ANC) ≥ 1,000 cells/mm\^3 (1.0 x 10\^9/L)
• •* Platelet count ≥ 75,000 cells/mm\^3 (75 x 10\^9/L)
• •* Hemoglobin ≥ 8.0 g/dl
• •* Total Bilirubin ≤ 1.5 x upper limit of normal (ULN), or patients diagnosed with Gilberts syndrome, that have been reviewed and approved by the medical monitor.
• •* Aspartate transaminase (AST /SGOT) and alanine transaminase (ALT/SGPT) ≤ 3.0 x ULN.
• •* Renal function: Estimated creatinine clearance by Cockcroft-Gault formula ≥ 45 mL/min.
• •11. Must be able to take antithrombotic prophylaxis.
• •12. Must have, or be willing to have an acceptable central catheter. (Port a cath, peripherally inserted central catheter \[PICC-line\], or central venous catheter) (Insertion only required if randomized to Arm A).