This is a phase I, dose-escalation study of bortezomib followed by a phase II study.
Phase I:
\- Induction therapy: Patients receive bortezomib IV over 3-5 seconds on days 1, 8, 15, and 22, rituximab IV on days 8 and 15, and yttrium Y 90 ibritumomab tiuxetan IV over 10 minutes on day 15.
Cohorts of 3-6 patients receive escalating doses of bortezomib until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 6 patients experience dose-limiting toxicity.
\- Consolidation therapy: Beginning 6-7 weeks after completing induction therapy, patients receive bortezomib IV over 3-5 seconds on days 1, 8, and 15. Treatment repeats every 28 days for 3 courses in the absence of disease progression or unacceptable toxicity.
Phase II: Patients receive induction therapy and consolidation therapy as in phase I, with bortezomib administered at the MTD determined in phase I.
After completion of study treatment, patients are followed every 3 months for 1 year, every 6 months for 1 year, and then annually thereafter.
A total of 24 patients will be accrued for this study.
