Comparison of the Effectiveness and Safety of the Oral Selective Inhibitor of Nuclear Export, Selinexor, in Diffuse Large B Cell Lymphoma Subtypes

Novel Targets and Advanced Therapies in Diffuse Large B Cell Lymphomas

Since the introduction of rituximab in the late 1990s, significant progress has been made in advancing targeted therapies for B cell lymphomas, improving patients' chance of being cured and clinicians' therapeutic armamentarium. A better understanding of disease biology and pathogenic pathways, coupled with refinements in immunophenotypic and molecular diagnostics, have been instrumental in these achievements. While traditional chemotherapy remains fundamental in most cases, concerns surrounding chemorefractoriness and cumulative toxicities, particularly the depletion of the hemopoietic reserve, underscore the imperative for personalized treatment approaches. Integrating targeted agents, notably monoclonal antibodies, alongside chemotherapy has yielded heightened response rates and prolonged survival. A notable paradigm shift is underway with innovative-targeted therapies replacing cytotoxic drugs, challenging conventional salvage strategies like stem cell transplantation. This review examines the landscape of emerging targets for lymphoma cells and explores innovative therapies for diffuse large B cell lymphoma (DLBCL). From Chimeric Antigen Receptor-T cells to more potent monoclonal antibodies, antibody-drug conjugates, bispecific antibodies, checkpoint inhibitors, and small molecules targeting intracellular pathways, each modality offers promising avenues for therapeutic advancement. This review aims to furnish insights into their potential implications for the future of DLBCL treatment strategies.

Sequencing therapy in relapsed DLBCL

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoid malignancy worldwide, comprising approximately 30% of all lymphomas. Currently, 50% to 60% of patients diagnosed with DLBCL are alive at 5 years and cured with modern therapy, but about 10% to 15% of patients are refractory to first-line therapy, and an additional 20% to 30% relapse following a complete response. Patients who have relapses beyond 2 years may experience more favorable outcomes and have forms of DLBCL that can be distinguished biologically. Patients who experience early relapse or who have primary refractory disease (less than a complete response or relapse within 3 to 6 months of initial therapy) have worse outcomes. For decades, the standard of care treatment strategy for fit patients with relapsed DLBCL has been salvage therapy with non-cross-resistant combination chemoimmunotherapy regimens followed by high-dose chemotherapy and autologous stem cell transplantation (ASCT) as stem cell rescue for patients with chemosensitive disease. Recent data suggest that certain patients may benefit from chimeric antigen receptor T-cell therapy (CAR T) in the second-line setting. Additional novel therapies exist for patients who are ineligible, who are unable to access these therapies, or who fail ASCT and/or CAR T. Despite the advent of new therapies for DLBCL and improved outcomes, DLBCL remains a life-threatening illness. Thus, it is essential for clinicians to engage in serious illness conversations with their patients. Goals-of-care communication can be improved through skills-based training and has been demonstrated to have an impact on patient experiences.

DLBCL 1L—What to Expect beyond R-CHOP?

Simple Summary

Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive non-Hodgkin’s lymphoma. About two-thirds of patients are cured by the first-line (1L) standard of care (SOC), the R-CHOP (Rituximab, Cyclophosphamide, Doxorubicin, Vincristine and Prednisolone) immunochemotherapy protocol. The profound molecular heterogeneity of DLBCL is the underlying reason why many patients, despite improved next-line options, eventually succumb to the disease. Hence, enhancing the efficacy of 1L treatment is critical for improving long-term outcomes in DLBCL. A plethora of novel treatment options with potential in later lines is currently under evaluation in 1L settings. We summarize here the established and emerging strategies for newly diagnosed DLBCL and emphasize the need for individualized treatment decisions.

Abstract

The R-CHOP immunochemotherapy protocol has been the first-line (1L) standard of care (SOC) for diffuse large B-cell lymphoma (DLBCL) patients for decades and is curative in approximately two-thirds of patients. Numerous randomized phase III trials, most of them in an “R-CHOP ± X” design, failed to further improve outcomes. This was mainly due to increased toxicity, the large proportion of patients not in need of more than R-CHOP, and the extensive molecular heterogeneity of the disease, raising the bar for “one-size-fits-all” concepts. Recently, an R-CHP regimen extended by the anti-CD79b antibody–drug conjugate (ADC) Polatuzumab Vedotin proved superior to R-CHOP in terms of progression-free survival (PFS) in the POLARIX phase III trial. Moreover, a number of targeted agents, especially the Bruton’s tyrosine kinase (BTK) inhibitor Ibrutinib, seem to have activity in certain patient subsets in 1L and are currently being tested in front-line regimens. Chimeric antigen receptor (CAR) T-cells, achieving remarkable results in ≥3L scenarios, are being exploited in earlier lines of therapy, while T-cell-engaging bispecific antibodies emerge as conceptual competitors of CAR T-cells. Hence, we present here the findings and lessons learnt from phase III 1L trials and piloting phase II studies in relapsed/refractory (R/R) and 1L settings, and survey chemotherapy-free regimens with respect to their efficacy and future potential in 1L. Novel agents and their mode of action will be discussed in light of the molecular landscape of DLBCL and personalized 1L perspectives for the challenging patient population not cured by the SOC.

The Association between Patient Characteristics and the Efficacy and Safety of Selinexor in Diffuse Large B-Cell Lymphoma in the SADAL Study

Simple Summary

Diffuse large B-cell lymphoma (DLBCL) is a complex disease. A combination of immunotherapy and chemotherapy is used to treat DLBCL at initial diagnosis. Additional treatments are available when DLBCL does not respond to initial treatment; however, for many patients, DLBCL will stop responding to treatment (relapse) or may not respond at all (refractory). Selinexor is a novel, oral medication that belongs to a class of drugs called selective inhibitors of nuclear export, and it works by killing cancer cells in patients with DLBCL that has relapsed after or is refractory to at least two treatments. When deciding on a course of treatment, it is useful for physicians to know which frequently described clinical characteristics of DLBCL affect the activity and tolerability of selinexor. We found that selinexor showed similar activity and tolerability across most of the frequently described clinical characteristics assessed.

Abstract

Selinexor, an oral selective inhibitor of nuclear export, was evaluated in the Phase 2b SADAL study in patients with diffuse large B-cell lymphoma (DLBCL) who previously received two to five prior systemic regimens. In post hoc analyses, we analyzed several categories of patient characteristics (age, renal function, DLBCL subtype, absolute lymphocyte count, transplant status, number of prior lines of therapy, refractory status, Ann Arbor disease stage, and lactate dehydrogenase) at baseline, i.e., during screening procedures, to determine their potential contributions to the efficacy (overall response rate [ORR], duration of response [DOR], overall survival [OS]) and tolerability of selinexor. Across most categories of characteristics, no significant difference was observed in ORR or DOR. OS was significantly longer for patients < 65 vs. ≥ 65 years, and for those with lymphocyte counts ≥ 1000/µL vs. < 1000/µL or lactate dehydrogenase ≤ ULN vs. > ULN. The most common adverse events (AEs) across the characteristics were thrombocytopenia and nausea, and similar rates of grade 3 AEs and serious AEs were observed. With its oral administration, novel mechanism of action, and consistency in responses in heavily pretreated patients, selinexor may help to address an important unmet clinical need in the treatment of DLBCL.