Safety concerns (IgM Flare)

Pomalidomide is a newly discovered drug that may stop cancer cells from growing abnormally. Pomalidomide may also stimulate the immune system to fight the cancer cells and possibly improve the effectiveness of dexamethasone and rituximab to fight the Waldenstrom's Macroglobulinemia (WM) cancer cells. This drug have been used in multiple myeloma and information from these other research studies suggests that Pomalidomide may help to reduce or prevent the growth of cancer cells.

• Participants will be given a study drug-dosing calendar for each treatment cycle. Each treatment cycle lasts 28 days during which time participants will take Pomalidomide orally once a day. Dexamethasone and rituximab will be administered intravenously on weeks 1, 2, 3, 4 and on weeks 12, 13, 14, 15.
• Since we are looking for the highest dose of Pomalidomide in combination with dexamethasone and rituximab which can be administered safely without severe or unmanageable side effects, not everyone who participates will receive the same dose of the study drug. The dose participants will get will depend on the number of participants who have been enrolled in the study and how well they have tolerated their doses.
• As long as there is no evidence that the participant's Waldenstrom's Macroglobulinemia has progressed, they can continue to receive Pomalidomide for up to 52 weeks. Participants will be asked to return to the clinic for follow-up tests at least every three months for four years.

Inclusion Criteria:

• 18 years of age or older
• Able to adhere to the study visit schedule and other protocol requirements
• Clinicopathological diagnosis of Waldenstrom's macroglobulinemia using consensus panel criteria
• CD20 positive based on any previous performed bone marrow immunohistochemistry or flow cytometric analysis
• Meet criteria to treat based on consensus panel criteria
• Patient must have received at least one previous therapy for WM
• All previous cancer therapy, including radiation, hormonal therapy and surgery, must have been discontinued at least 4 weeks prior to treatment in this study
• Measurable disease, defined as presence of immunoglobulin M (IgM) paraprotein with a minimum IgM level of 2 times (or greater) the upper limit of each institution's normal value is required
• ECOG Performance status of 0, 1 or 2
• Laboratory tests within ranges outlined in the protocol
• Disease free of prior malignancies for 5 years or more with exception of currently treated basal cell, squamous cell carcinoma of the skin, or carcinoma in situ of the cervix or breast
• Screening of patients at high risk of HBV or HCV infection
• Willing and able to take aspirin or alternate prophylactic anticoagulants

Exclusion Criteria:

• Any serious medical condition, laboratory abnormality, or psychiatric illness
• Pregnant or lactating females
• Any condition, including the presence of laboratory abnormalities, which places the subject at unacceptable risk if he/she were to participate in the study or confounds the ability to interpret data from the study
• Resistance or intolerance to prior rituximab therapy
• Previous therapy with thalidomide or lenalidomide
• Known hypersensitivity to thalidomide, lenalidomide or pomalidomide
• The development of erythema nodosum if characterized by a desquamating rash while taking similar drugs
• Concurrent use of other anti-cancer agents or treatments
• History of non-compliance to medical regimens
• Patients unwilling to or unable to comply with the protocol
• Known positive for HIV or hepatitis infection
• Any history of CVA (Cerebral Vascular Accident/stroke) or clots
• Active DVT or PE that has not been therapeutically anticoagulated
• NYHA classification III and greater heart failure
• Any patient that is unable to ingest or process pomalidomide

Adverse events were collected over a 3 year period.

Pomalidomide and rituximab could have a synergistic effect on serum IgM levels and produce an IgM flare. The highest dose of pomalidomide in this trial was 1mg. The study was permanently closed to accrual given the safety concerns with the IgM flare.