This randomized phase II trial studies how well pomalidomide and dexamethasone work compared to lenalidomide and dexamethasone in treating patients with multiple myeloma that has returned after a period of improvement (relapsed) or did not respond to previous treatment with lenalidomide (refractory). Pomalidomide and lenalidomide may help the immune system kill cancer cells and may also prevent the growth of new blood vessels that tumors need to grow. Drugs used in chemotherapy, such as dexamethasone, work in different ways to stop the growth of cancer cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Dexamethasone may also help pomalidomide and lenalidomide work better by making cancer cells more sensitive to the drugs. It is not yet known whether pomalidomide and dexamethasone or lenalidomide and dexamethasone are effective in treating patients with relapsed or refractory multiple myeloma.

PRIMARY OBJECTIVES:

I. To assess the confirmed response rate of the combination of lenalidomide and dexamethasone in patients with relapsed myeloma who have previously become refractory to lenalidomide. (Arm A) II. To assess the confirmed response rate of the combination of pomalidomide and dexamethasone in patients with relapsed myeloma who have previously become refractory to lenalidomide. (Arm B)

SECONDARY OBJECTIVES:

I. To assess the toxicity in each arm in patients with relapsed myeloma who have previously received lenalidomide.

II. To assess the response rates with pomalidomide and dexamethasone in patients relapsing on lenalidomide and dexamethasone. (Arm A) III. To assess time to progression and overall survival with each approach.

OUTLINE: Patients are randomized to 1 of 2 treatment arms.

ARM A: Patients receive lenalidomide orally (PO) daily on days 1-21 and dexamethasone PO on days 1, 8, 15, and 22. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity. Patients experiencing progressive disease may crossover to arm B.

ARM B: Patients receive pomalidomide PO daily on days 1-21 and dexamethasone as in arm A. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity.

After completion of study treatment, patients are followed up periodically.

Inclusion Criteria:

• Calculated creatinine clearance >= 30 ml/min by Cockcroft-Gault formula

• Absolute neutrophil count >= 1000uL

• (Untransfused) platelet count >= 50000/uL

• Hemoglobin >= 8.0 g/dL

• Relapsed myeloma that previously became refractory to lenalidomide, after initial response of partial response or better to the drug; refractory is defined as progression on treatment with a dose of at least 10 mg daily for lenalidomide; greater than or equal to 180 days must have elapsed since previous lenalidomide therapy was stopped

• Measurable disease of multiple myeloma as defined by at least ONE of the following:

  • Serum monoclonal protein >= 1.0 g/dL
  • >= 200 mg of monoclonal protein in the urine on 24 hour electrophoresis
  • Serum immunoglobulin free light chain >= 10 mg/dL AND abnormal serum immunoglobulin kappa to lambda free light chain ratio
  • Monoclonal bone marrow plasmacytosis >= 30% (evaluable disease)

• Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0, 1 or 2

• Previously treated; NOTE: no limit to prior therapy provided there is adequate residual organ function

• Provide informed written consent

• Females of childbearing potential (FCBP)* must have a negative serum pregnancy test with a sensitivity of at least 50 mIU/mL within 10 - 14 days prior to and again within 24 hours prior to prescribing lenalidomide for cycle 1 (prescriptions must be filled within 7 days as required by Revlimid Risk Evaluation and Mitigation Strategy [REMS]), and must either commit to continued abstinence from heterosexual intercourse or begin TWO acceptable methods of birth control, one highly effective method and one additional effective method AT THE SAME TIME, at least 28 days before she starts taking lenalidomide; FCBP must also agree to ongoing pregnancy testing; men must agree to use a latex condom during sexual contact with a FCBP even if they have had a successful vasectomy; all study participants must be registered into the Revlimid REMS program, and be willing and able to comply with the requirements of Revlimid REMS program

  • A female of childbearing potential is a sexually mature woman who: 1) has not undergone a hysterectomy or bilateral oophorectomy; or 2) has not been naturally postmenopausal for at least 24 consecutive months (i.e., has had menses at any time in the preceding 24 consecutive months)

• Willing to return to Mayo Clinic enrolling institution for follow-up

Exclusion Criteria:

• Residual toxicity of > grade 1 from prior therapy

• Other active malignancy < 1 year prior to registration; EXCEPTIONS: non-melanotic skin cancer or carcinoma-in-situ of the cervix; NOTE: if there is a history of prior malignancy, they must not be receiving other specific treatment for their cancer

• Any of the following:

  • Pregnant women
  • Nursing women (lactating females must agree not to breast feed while taking lenalidomide)
  • Men or women of childbearing potential who are unwilling to employ adequate contraception (condoms, diaphragm, birth control pills, injections, intrauterine device [IUD], or abstinence, etc.)

• Other co-morbidity which would interfere with patient's ability to participate in trial, e.g. uncontrolled infection, uncompensated heart or lung disease

• Other concurrent chemotherapy, radiotherapy, or any ancillary therapy considered investigational; NOTE: bisphosphonates are considered to be supportive care rather than therapy, and are thus allowed while on protocol treatment

• New York Heart Association classification III or IV

• Diagnosed active deep vein thrombosis (DVT) that has not been therapeutically anticoagulated