Ixazomib and Rituximab in Treating Patients With Relapsed or Refractory Mantle Cell Lymphoma

PRIMARY OBJECTIVES: I. To evaluate the complete remission rate of Bruton's tyrosine kinase (BTK) inhibitor refractory mantle cell lymphoma (MCL) patients with ixazomib citrate (ixazomib) and rituximab at 16 weeks of therapy. SECONDARY OBJECTIVES: I. To evaluate overall response rate (ORR) assessed by Lugano criteria. II. To evaluate progression free survival (PFS) and overall survival (OS). III. To evaluate the safety and tolerability. TERTIARY/EXPLORATORY OBJECTIVES: I. To evaluate biomarkers of response to treatment and mechanisms of resistance with pretreatment and post-treatment bone marrow and blood samples with deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) sequencing and immune profiling by flow cytometry. OUTLINE: Patients receive ixazomib orally (PO) on days 1, 8, and 15. Treatment repeats every 28 days for up to 12 cycles in the absence of disease progression or unacceptable toxicity. Patients also receive rituximab intravenously (IV) over 4-8 hours on days 1, 8, 15, and 22 of cycle 1. Beginning in cycle 3, patients receive rituximab IV over 4-8 hours on day 1. Treatment repeats every 28 days up to cycle 12 in the absence of disease progression or unacceptable toxicity. Patients benefiting from treatment may continue to receive ixazomib indefinitely in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up periodically.