Combination Bortezomib and Rituximab in Patients With Waldenstrom's Macroglobulinemia

- Participants will receive 6 cycles of the study treatment with bortezomib and rituximab.
Each cycle is 28 days long (4 weeks).

- Participants will receive Rituximab intravenously once a week for the first and fourth
cycles only. Participants will receive bortezomib once a week for three weeks on and one
week off every cycle, for a total of 6 cycles.

- During the rituximab infusion, the participants blood pressure and pulse will be
monitored frequently. The rate of infusion may be decreased depending upon the side
effects that are experienced.

- Blood samples will be collected before the first dose and on follow up with every cycle.
Blood counts will also be performed every week.

- Routine physical exams will be performed at each evaluation. A PET/CAT scan of the
chest, abdomen and pelvis at the end of treatment. This scan is required to assess the
response of the participants disease.

- In order to learn more on how bortezomib and rituximab affect WM, a bone marrow biopsy
will be performed.

- We anticipate that participants will complete the active therapy over a period of 6
cycles provided that they are benefiting from therapy and have not had any serious side
effects. The participant will be followed every three months for 2 years for office
visits and laboratory tests.

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