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.

Diagnosis of GATA2 haplo-insufficiency in a young woman prompted by pancytopenia with deficiencies of B-cell and dendritic cell development.

BACKGROUND: GATA2 deficiency presents with a spectrum of phenotypes including increased susceptibility to viral and bacterial infections, multi-lineage cytopenias, aplastic anemia, leukemic transformation and lymphedema. Allogeneic transplantation is only curative therapy for GATA2 deficiency, but is associated with significant treatment related morbidity and mortality. Given the spectrum of clinical presentation, accurate diagnosis of GATA2 deficiency is necessary to identify patients early in their disease course when allogeneic bone marrow transplantation may be of clinical benefit. CASE PRESENTATION: In this report, we present a GATA2 mutation diagnosed in 23-year-old woman presenting with pancytopenia, recurring oral blisters, fatigue and chronic pain. We describe markedly low levels of mature B-cells in the blood and bone marrow and the absence of detectable blood dendritic cells with normal serum immunoglobulin levels and normal numbers of marrow plasma cells. She was ultimately diagnosed with GATA2 haplo-insufficiency due to a GATA2 germ-line mutation and underwent a successful allogeneic bone marrow transplant from a 10/10 HLA matched unrelated donor. CONCLUSIONS: The case illustrates the diagnostic difficulties in identifying GATA2 deficiencies and the importance of family history and genetic testing. GATA2 plays an important role in B-cell and dendritic cell development, and decreased numbers of those cells is a characteristic feature that should prompt consideration of GATA2 deficiency in a patient with pancytopenia. Maturation of B-cells to long-lived plasma cells is relatively unaffected in GATA2 deficiency. Allogeneic stem cell transplantation can correct immune-deficiencies and prevent leukemic transformation in patients with GATA2 deficiency.

Effective management strategies for patients with marginal zone lymphoma.

Marginal zone lymphoma (MZL) is an uncommon indolent lymphoma classified into subtypes based on primary site of involvement: splenic, nodal and extranodal. MZLs' relative rarity has largely precluded adoption of a standard management strategy. Here, we provide an overview of the epidemiology, clinical behavior and therapeutic approaches for each subtype. Biologic insights into lymphomagenesis have identified B-cell receptor signaling as a rational therapeutic target. Recent clinical data suggest that novel agents targeting this pathway, including the Bruton's tyrosine kinase inhibitor, ibrutinib, show significant promise in treatment of relapsed MZL. More work is needed to evaluate these agents' activity in the front-line setting, possible combination regimens and the impact of resistance to B-cell receptor-targeted agents in order to optimize therapy in MZL.