Lenalidomide and Rituximab in Treating Patients With Recurrent and/or Refractory Multiple Myeloma

Inclusion Criteria

• •DISEASE CHARACTERISTICS:
• •Histologically confirmed CD20+ multiple myeloma
• •* CD20+ disease defined as co-expression of CD20 on ≥ 25% of the clonal plasma cell population as defined by immunohistochemical or flow cytometric staining of a bone marrow or plasmacytoma specimen obtained at study entry
• •* For flow cytometry, this is determined by calculating the frequency of CD20+ CD138+ double-positive cells within the total CD138+ plasma cell population
• •* For immunohistochemistry, this is determined by dual staining for CD20 and the involved clonal light chain (kappa or lambda), with a determination of the percent double-positive (≤ 25% or ≥ 25%)
• •Symptomatic multiple myeloma that has relapsed or progressed after at least 1 prior anti-myeloma therapeutic regimen
• •PATIENT CHARACTERISTICS:
• •ECOG performance status 0-2
• •Life expectancy \> 16 weeks (4 months)
• •ANC ≥ 1,500/μL (unless low ANC due to multiple myeloma)
• •Platelets ≥ 100,000/μL (unless low platelets are due to multiple myeloma)
• •Serum bilirubin ≤ 2.0 mg/dL
• •AST, ALT, and alkaline phosphatase \< 3 times upper limit of normal
• •Serum creatinine ≤ 2.5 mg/dL
• •Able to understand the investigational nature of lenalidomide and rituximab combination therapy and to give informed consent
• •Not pregnant or nursing
• •Negative pregnancy test
• •Fertile patients must use effective double-method contraception at least 28 days before, during, and for at least 28 days after completion or discontinuation of study treatment
• •Able to take acetylsalicylic acid (ASA) (325 mg) daily as prophylactic anticoagulation (patients intolerant to ASA may use warfarin or low molecular weight heparin)
• •Prior malignancies with a disease free interval of ≥ 5 years allowed
• •No history of thromboembolic disease within the past 6 months, regardless of anticoagulation
• •No myocardial infarction within the past 6 months
• •No New York Hospital Association class III or IV heart failure
• •No uncontrolled angina
• •No severe uncontrolled ventricular arrhythmias
• •No active hepatitis B or C infection
• •No HIV 1or 2 positivity
• •No acute ischemia or active conduction system abnormalities as evidenced by ECG
• •No history of hypersensitivity reactions to lenalidomide, thalidomide, or rituximab
• •No other medical condition or laboratory evaluation that, in the treating physician's or principal investigators' opinion, makes the patient unsuitable to participate in this clinical trial
• •No concurrent active malignancy other than nonmelanoma skin cancers or carcinoma-in-situ of the cervix
• •PRIOR CONCURRENT THERAPY:
• •At least 3 weeks since prior therapy, including radiotherapy
• •Prior lenalidomide or thalidomide allowed
• •No prior rituximab