Ixazomib With or Without Rituximab Following Maintenance Autologous Stem Cell Transplant in Mantle Cell Lymphoma: A Single-Center Phase I Trial.

BACKGROUND: Induction chemotherapy followed by autologous stem cell transplantation (ASCT) is a standard first-line treatment for fit patients with mantle cell lymphoma (MCL). We conducted a single-center phase I trial investigating post-transplant maintenance with ixazomib, an oral proteasome inhibitor. METHODS: Patients enrolled between days +70 and +180 post ASCT. Patients received ixazomib per dose cohort on days 1, 8, and 15 of each 28-day cycle for up to 10 cycles. During recruitment, published phase III data reported a survival benefit with rituximab maintenance, so all subsequent patients received ixazomib 4 mg at the same schedule along with rituximab 375 mg/m2 on day 1 of cycles 1, 3, 5, 7, and 9. All patients were in complete remission at enrollment. RESULTS: Seven patients received ixazomib monotherapy; 1 dose limiting toxicity (grade 3 neutropenia) occurred at dose level 2 (4 mg). Five patients received combination Ixazomib plus rituximab, with 2 experiencing DLTs (both Grade 4 neutropenia). Grade 3-4 neutropenia, lymphopenia, and thrombocytopenia occurred in 57%, 8%, and 8% of patients, respectively. Non-hematologic adverse events (AE) included nausea (42%), peripheral neuropathy (42%), and abdominal discomfort (33%), all of which were grade 1 or 2 in severity. There were no infectious AEs. With a median follow up of 46 months, all patients are alive and in complete remission. CONCLUSION: The trial was closed to further accrual due to high rates of treatment-related myelosuppression. The current dose and schedule of ixazomib, especially when combined with rituximab, results in unacceptable hematologic toxicity when administered as post-transplant maintenance in MCL. Ixazomib maintenance micro abstract: The authors conducted a phase I study investigating the use of ixazomib, an oral proteasome inhibitor, with or without rituximab in patients with mantle cell lymphoma in first remission following chemoimmunotherapy and autologous stem cell transplantation. All patients treated on study remain in complete remission with a median follow-up of 46 months, but the study was closed early due to a high rate of hematologic adverse events.

A phase II study of bortezomib added to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone in patients with previously untreated indolent non-Hodgkin's lymphoma.

Bortezomib-containing combinations are active in non-Hodgkin lymphoma (NHL) although peripheral neuropathy can limit their dose intensity. Based on our phase I findings, we conducted a phase II trial of bortezomib in combination with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) with a modified dose of vincristine. Patients with untreated indolent NHL received bortezomib (1·6 mg/m(2) ) on days 1 and 8 of a 21-day cycle for up to 8 cycles and R-CHOP with a 1·5 mg cap of vincristine. Patients achieving a complete response (CR) received maintenance rituximab, and remaining patients received maintenance rituximab and bortezomib. The primary endpoint was CR rate; secondary survival analyses were evaluated using the Kaplan-Meier method. Among 29 eligible patients, NHL morphologies included follicular (n = 20), marginal zone (n = 5) and small lymphocytic lymphoma (n = 4). Nineteen patients had CR (66%) and 10 had partial response (34%), yielding a 100% overall response rate. With a median follow-up of 48·7 months, the 4-year progression-free and overall survivals were 83% and 93%. Twenty-two patients experienced peripheral neuropathy of any grade, and two had grade 3 neuropathy. The combination of bortezomib with R-CHOP is effective for indolent NHL, and we plan to evaluate therapies incorporating novel proteasome inhibitors in future studies in NHL.

Combination of GM-CSF With Fludarabine-Containing Regimens in Chronic Lymphocytic Leukemia and Indolent Non-Hodgkin Lymphoma.

BACKGROUND: Granulocyte-monocyte colony stimulating factor (GM-CSF) is a hematopoietic cytokine with immunomodulatory activity that has preclinical evidence for enhancement of antitumor immunity when administered in combination with chemotherapy. We evaluated the utility of GM-CSF with chemoimmunotherapy in patients with indolent non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL) in a pilot study. PATIENTS AND METHODS: Patients with previously untreated, relapsed, or refractory indolent NHL or CLL were treated with GM-CSF, rituximab, fludarabine, and cyclophosphamide or mitoxantrone for a maximum of 6 cycles. RESULTS: Sixteen patients were enrolled, including 1 patient who did not receive study therapy. Of the 15 remaining patients, 6 received cyclophosphamide and 9 received mitoxantrone in combination with fludarabine, rituximab, and GM-CSF. The overall response rate for all patients was 87%. Nine patients have subsequently had relapse of their disease, and 6 remained in remission at last study contact. There were no toxic deaths during the study. CONCLUSION: GM-CSF-based chemoimmunotherapy was well-tolerated and resulted in a high response rate and warrants evaluation in larger studies.