Inclusion Criteria:

- Age >= 18 years.

- Must have received prior therapy for their WM and have relapsed or refractory WM. Any
number of prior therapies is acceptable.

- Measurable disease, defined as presence of immunoglobulin M (IgM) paraprotein with a
minimum IgM level of > 2 times the upper limit of each institution's normal value is
required and over 10% of lymphoplasmacytic cells in the bone marrow.

- ECOG Performance Status (PS) 0, 1, or 2.

- The following laboratory values obtained 14 days prior to registration

- ANC >= 1 x109/L

- PLT >= 75 x109/L

- Total bilirubin ≤ 2.0 mg/dL (If total is elevated check direct and if normal patient
is eligible.)

- AST <= 3 x upper limit of normal (ULN)

- Creatinine <= 2 x ULN

- Ability to provide informed consent.

- Life expectancy >= 12 weeks.

Exclusion Criteria:

- Uncontrolled infection.

- Other active malignancies.

- CNS involvement.

- Cytotoxic chemotherapy ≤ 3 weeks, or biologic therapy ≤ 2 weeks, or corticosteroids ≤
2 weeks, prior to registration. Patients may be receiving chronic corticosteroids if
they are being given for disorders other than WM such as auto-immune diseases.
Plasmapheresis is not considered as an active therapy and can be used at the
physician's discretion.

- Other concurrent chemotherapy, immunotherapy, radiotherapy, or any ancillary therapy
considered investigational.

- Any of the following:

- Pregnant women

- Nursing women

- 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.)

- Known to be HIV positive.

- Radiation therapy ≤ 2 weeks prior to registration.