Inclusion Criteria:

- 18 years of age or older

- Patients with previously untreated WM and those who have received prior therapy are
eligible

- Must have received prior therapy for their WM and have relapsed or refractory WM.

- CD20 positive disease based on any previous bone marrow immuno-histochemistry or flow
cytometric analysis performed up to 3 months prior to enrollment.

- Measurable disease

- ECOG Performance Status 0,1, or 2

- Total bilirubin < 2.0 mg/dl

- AST < 3 x ULN

- Life expectancy of greater than 12 weeks

Exclusion Criteria:

- Uncontrolled infection

- Other active malignancies

- Cytotoxic chemotherapy less than 3 weeks, or biologic therapy less than 2 weeks, or
corticosteroids less than 2 weeks, prior to registration.

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

- Known to be HIV positive or HEP B positive

- Radiation therapy less than 2 weeks prior to registration

- Grade 2 or greater peripheral neuropathy

- Myocardial infarction within 6 months rior to enrollment or has NYHA Class III or IV
heart failure, uncontrolled angina, severe uncontrolled ventricular arrhythmias, or
electrocardiographic evidence of acute ischemia or active conduction system
abnormalities.

- Hypersensitivity to bortezomib, boron, or mannitol

- Pregnant or breast feeding women

- Other investigational drugs within 14 days of enrollment

- Serious medical or psychiatric illness likely to interfere with participation