Bortezomib and Rituximab in Treating Patients With Post-Transplant Lymphoproliferative Disorders

OBJECTIVES: Primary * To estimate the overall (complete and partial) response rates in patients with CD20+ post-transplant lymphoproliferative disorders treated with bortezomib and rituximab. Secondary * To evaluate the duration of remission, time to treatment failure, relapse-free survival, and overall survival of these patients. * To characterize the quantitative and qualitative toxicities of this regimen. OUTLINE: * Induction therapy: Patients receive bortezomib intravenously (IV) and rituximab IV on days 1, 8, 15, and 22. Patients achieving complete remission (CR) after completion of induction therapy proceed to maintenance therapy after 6 months of rest. Patients achieving partial remission (PR) or stable disease after completion of induction therapy receive additional bortezomib IV on days 1, 4, 8, and 11. Treatment repeats every 21 days for up to 4 courses in the absence of disease progression or unacceptable toxicity. Patients achieving CR/PR after completion of bortezomib therapy proceed to maintenance therapy after 3 months of rest. * Maintenance therapy: Patients receive bortezomib IV and rituximab IV on days 1, 8, 15, and 22. Treatment repeats every 6 months for 4 courses in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed periodically for 2 years.