The following criteria is provided for health care professionals.

Key Inclusion Criteria:

1. Has a diagnosis of MM based on standard criteria21 as follows:

   • Major criteria:

     1. plasmacytomas on tissue biopsy
     2. bone marrow plasmacytosis (greater than 30% plasma cells)
     3. monoclonal immunoglobulin (Ig) spike on serum electrophoresis IgG greater than 3.5 g/dL or IgA greater than 2.0 g/dL; kappa or lambda light chain excretion greater than 1 g/day on 24 hour urine protein electrophoresis

   • Minor criteria:

     1. bone marrow plasmacytosis (10% to 30% plasma cells)
     2. monoclonal immunoglobulin present but of lesser magnitude than given under major criteria
     3. lytic bone lesions
     4. normal IgM less than 50 mg/dL, IgA less than 100 mg/dL, or IgG less than 600 mg/dL

   Any of the following sets of criteria will confirm the diagnosis of multiple myeloma:

   • any 2 of the major criteria
   • major criterion 1 plus minor criterion 2, 3, or 4
   • major criterion 3 plus minor criterion 1 or 3
   • minor criteria 1, 2, and 3, or 1, 2, and 4

2. Currently has MM with measurable disease, defined as:

   • a monoclonal immunoglobulin spike on serum electrophoresis of at least 0.5 g/dL and/or
   • urine monoclonal protein levels of at least 200 mg/24 hours
   • for patients without measurable serum and urine M-protein levels, an abnormal free light chain ratio (normal value: 0.26 - 1.65)

3. Currently has progressive MM that has relapsed while currently receiving or within 6 months of receiving the maximum tolerated dose of lenalidomide at the physician's discretion as part of a combination treatment that includes more than just steroids in a 21-day or a 28-day cycle schedule. MM patients that are relapsed or have refractory disease, as defined below, are both eligible for enrollment provided they fulfill the other eligibility criteria:

   • Patients are refractory to a lenalidomide combination regimen, when they progress while currently receiving the lenalidomide combination treatment or within 8 weeks of its last dose.
   • Patients are considered relapsed, when they progress between 8 and 26- weeks from their last dose of lenalidomide as part of a lenalidomide-combination therapy that includes more than just steroids.
   • Prior treatment with four days or less of a total of 400 mg of prednisone (or an equivalent potency of another steroid) for MM will not be considered a regimen
4. Able to take aspirin (acetylsalicylic acid, ASA) at 81 or 325 mg /daily as prophylactic anticoagulation (subjects intolerant to ASA may use warfarin or low molecular weight heparin)

Key Exclusion Criteria:

1. Plasma cell dyscrasia with polyneuropathy, organomegaly, endocrinopathy, monoclonal protein (M-protein) and skin changes (POEMS) syndrome22
2. Plasma cell leukemia
3. Primary amyloidosis
4. Non-hematologic malignancy within the past 5 years with the exception of a) adequately treated basal cell carcinoma, squamous cell skin cancer, or thyroid cancer; b) carcinoma in situ of the cervix or breast; c) prostate cancer of Gleason Grade 6 or less with stable prostate-specific antigen levels; or d) cancer considered cured by surgical resection or unlikely to impact survival during the duration of the study, such as localized transitional cell carcinoma of the bladder or benign tumors of the adrenal or pancreas
5. Impaired cardiac function or clinically significant cardiac diseases, including myocardial infarction within 6 months prior to enrollment, New York Heart Association (NYHA) Class II or greater heart failure, uncontrolled angina, clinically significant pericardial disease, severe uncontrolled ventricular arrhythmias, echocardiogram or multigated acquisition scan (MUGA) evidence of left ventricular ejection fraction (LVEF) below institutional normal within 28 days prior to enrollment, electrocardiographic evidence of acute ischemia or active conduction system abnormalities. Prior to study entry, any ECG abnormality at Screening has to be documented by the investigator as not medically relevant.
6. Received the following prior therapy:
   • Pomalidomide
   • Lenalidomide alone or in combination with steroids in their last treatment regimen. Interim therapy not containing lenalidomide between their last lenalidomide-containing regimen and the start of the trial.
   • A melphalan-containing regimen as the immediate prior line of treatment
   • Chemotherapy within 3 weeks of study drugs (6 weeks for nitrosoureas)
   • Corticosteroids (>10 mg /daily prednisone or equivalent) within 3 weeks of study drugs
   • Immunotherapy or antibody therapy as well as thalidomide, lenalidomide, arsenic trioxide or bortezomib within 21 days before study drugs
   • Extensive radiation therapy within 28 days before study drugs. Receipt of localized radiation therapy does not preclude enrollment.
   • Use of any other experimental drug or therapy within 28 days of study drugs
7. Known hypersensitivity to compounds of similar chemical or biological composition to thalidomide and lenalidomide.
8. The development of erythema nodosum if characterized by a desquamating rash while taking thalidomide or similar drugs