A Phase II Study Evaluating Combined Zevalin(Ibritumomab Tiuxetan)and Velcade(Bortezomib)in Relapsed/Refractory Mantle Cell Lymphoma

Inclusion Criteria:

- Patients with relapsed or refractory Mantle Cell lymphoma with measurable disease.

- Age > 18 years old

- Expected survival >/= 3 months

- ECOG performance status of 0, 1 or 2 at initiation of study (Appendix I).

- Laboratory tests meet the levels specified in the protocol

Exclusion Criteria:

- Patients must not have received chemotherapy, radiation or surgical resection of
malignancy within 3 weeks of study initiation. However, if they have received
nitrosurea or mitomycin C then they should not be enrolled in the study until 6 weeks
after therapy was last received.

- No limitations to number of prior therapies

- No prior radioimmunotherapy (RIT)

- Prior bortezomib is allowed

- Patient must be fully recovered from all toxicities associated with prior surgery,
radiation treatment, chemotherapy or immunotherapy.

- No active, serious infection or medical or psychiatric illness likely to interfere
with participation in this clinic trial

- No known HIV infection

- No active CNS involvement

- Bone Marrow Involvement >/= 25% within 30 days of initiation of study treatment

- Pregnant or breast feeding

- No patients who have received G-CSF or GM-CSF within the 14 days prior to initiating
protocol

- No patient who has had major surgery within the four weeks prior to initiating
protocol therapy

- No patients with pleural effusion or significant ascites