Allogeneic stem cell transplantation in patients with mantle cell lymphoma: results from the MANTLE-FIRST study on behalf of Fondazione Italiana Linfomi

Unmet needs in relapsed/refractory mantle cell lymphoma (r/r MCL) post-covalent Bruton tyrosine kinase inhibitor (BTKi): a systematic literature review and meta-analysis

To quantify the clinical unmet need of r/r MCL patients who progress on a covalent Bruton tyrosine kinase inhibitor (BTKi), we conducted a systematic review to identify studies that reported overall survival (OS), progression-free survival (PFS), or response outcomes of patients who received a chemo(immunotherapy) ± targeted agent standard therapy (STx) or brexucabtagene autoleucel (brexu-cel) in the post-BTKi setting. Twenty-six studies (23 observational; three trials) reporting outcomes from 2005 to 2022 were included. Using two-stage frequentist meta-analyses, the estimated median PFS/OS for patients treated with an STx was 7.6 months (95% CI: 3.9-14.6) and 9.1 months (95% CI: 7.3-11.3), respectively. The estimated objective response rate (ORR) was 45% (95% CI: 34-57%). For patients treated with brexu-cel, the estimated median PFS/OS was 14.9 months (95% CI: 10.5-21.0) and 32.1 months (95% CI: 25.2-41.2), with a pooled ORR of 89% (95% CI: 86-91%). Our findings highlight a significant unmet need for patients whose disease progresses on a covalent BTKi.

Allogeneic stem cell transplantation and CAR-T in B-cell Non-Hodgkin Lymphoma: a two-center experience and review of the literature

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is still a potentially curative option for B-cell Non-Hodgkin Lymphoma (B-NHL) in the modern immunotherapy era. The objective of this study was to analyze long-term outcomes of patients with B-NHL who received allo-HSCT. We analyzed overall survival (OS), progression-free survival (PFS) and graft versus host disease (GVHD) relapse-free survival (GRFS) in 53 patients undergoing allo-HSCT from two institutions. The median follow-up of the study was 72 months (range 29-115 months). The median number of lines of therapy before allo-HSCT was 3 (range 1-6) and twenty-eight patients (53%) had received a previous autologous transplant. The 3-year PFS, OS and GRFS were 55%, 63%, and 55%, respectively. One-year non-relapse mortality was 26%. Karnofsky Performance Scale < 90 was associated with worse OS in multivariable analysis. A non-comparative analysis of a cohort of 44 patients with similar characteristics who received chimeric antigen receptor T-cell therapy was done, showing a 1-year PFS and OS were 60% and 66%, respectively. Our data shows that allo-HSCT is still a useful option for treating selected patients with R/R B-NHL. Our retrospective analysis and review of the literature demonstrate that allo-HSCT can provide durable remissions in a subset of patients with R/R B-NHL.

Long-term outcome in patients with mantle cell lymphoma following high-dose therapy and autologous stem cell transplantation

BACKGROUND

Long-term clinical and molecular remissions in patients with mantle cell lymphoma (MCL) after autologous stem cell transplantation (ASCT) have been evaluated in only a few studies.

DESIGN AND METHODS

Sixty-five patients with MCL received ASCT (54 first-line ASCT, 10 second-line ASCT, and 1 third-line ASCT). In the case of long-term remission (≥5 years; n = 27), peripheral blood was tested for minimal residual disease (MRD) by t(11;14)- and IGH-PCR at the last follow-up.

RESULTS

Ten-year overall survival (OS), progression-free survival (PFS), and freedom from progression (FFP) after first-line ASCT were 64%, 52%, and 59% versus after second-line ASCT 50%, 20%, and 20%, respectively. Five-year OS, PFS, and FFP for the first-line cohort were 79%, 63%, and 69%, respectively. Five-year OS, PFS, and FFP after second-line ASCT were 60%, 30%, and 30%, respectively. Treatment-related mortality (3 months after ASCT) was 1.5%. So far 26 patients developed sustained long-term clinical and molecular complete remissions of up to 19 years following ASCT in first treatment line.

CONCLUSION

Sustained long-term clinical and molecular remissions are achievable following ASCT.

The place of allogeneic stem cell transplantation in aggressive B-cell non-Hodgkin lymphoma in the era of CAR-T-cell therapy

Chimeric antigen receptor T (CAR-T) cells are a treatment option for patients with relapse/refractory (R/R) non-Hodgkin lymphoma (NHL), acute lymphoid leukemia and multiple myeloma. To date, diffuse large B-cell lymphoma (DLBCL), mantle cell lymphoma (MCL), follicular lymphoma (FL), and chronic lymphocytic leukemia (CLL) have been successfully treated with CAR-T cells directed against the CD19 antigen. However, when R/R disease persists after several treatment lines, patients with these diseases are often referred to transplantation centres to receive allogeneic stem cell transplantation (ALLO-SCT). ALLO-SCT and CAR-T cells share mechanism of actions, inducing immune effects of T-cells (and other cells after transplantation) against lymphoma cells, but they differ in several other characteristics. These differences justify unique positioning of each therapy within treatment algorithms. In this paper, we analyzed the results obtained after ALLO-SCT and CAR-T-cell therapy in patients with aggressive lymphomas (large B-cell lymphoma and MCL) to identify the ideal scenarios in which these 2 immunological therapies should be employed.

Use of BTK inhibitors with focus on ibrutinib in mantle cell lymphoma: an expert panel opinion statement

The introduction of BTK inhibitors transformed the management of patients with mantle cell lymphoma (MCL). Ibrutinib, the first-in-class BTK inhibitor is now approved in more than 80 countries and there are over 20 new BTK inhibitors in development. In addition, novel agents show potential clinical activity (alone and in combination) and are in the approval phase and/or being studied in ongoing clinical trials. How does the practicing clinician decide on the optimal therapeutic strategy for this highly heterogenous disease? In July 2020 a group of experts from Italy, convened a meeting to address and provide clarification on a series of outstanding issues in the treatment of MCL with the view of providing clinical guidance on its management. This expert opinion statement represents the panel's collective analysis, evaluation, and recommendations and is made up of a series of questions and answers (in the form of a review of the pertinent literature) designed to replicate those posed by practicing clinicians in Italy but which are applicable to clinical settings worldwide. This article is protected by copyright. All rights reserved.

Relapsed/Refractory Mantle Cell Lymphoma: Beyond BTK Inhibitors

Mantle cell lymphoma (MCL) is a rare mature B-cell non-Hodgkin lymphoma (B-NHL) with historically poor outcomes. Virtually all patients will eventually experience refractory or relapsed (R/R) disease, with a virulent course of resistance and serial relapses, making treatment challenging. The available therapies for R/R MCL are not curative with conventional therapy, their goal being to palliate and prolong survival. A variety of agents approved for R/R MCL, including Bruton's tyrosine kinase inhibitors (BTKi), changed the treatment landscape of R/R MCL. In the pre-BTKi era, the median progression-free survival (PFS) in R/R disease was 4-9 months. With the introduction of ibrutinib, the median PFS improved to 13-14.6 months. Despite these impressive results, the duration of response is limited, and resistance to BTKi inevitably develops in a subset of patients. Outcomes after progression on BTKi are extremely poor, with a median overall survival (OS) of 6 to 10 months. Certain therapies, such as chimeric antigen receptor (CAR) T cells, have shown promising results after BTKi failure. The preferred combination and sequencing of therapies beyond BTKi remain unestablished and are currently being investigated. In this review, we describe the current evidence for the available treatment of R/R MCL after progression on BTKi.

Mantle cell lymphoma management trends and novel agents: where are we going?

The heterogeneity in disease pathology, the unpredictability in disease prognosis, and the variability in response to therapy make mantle cell lymphoma (MCL) a focus of novel therapeutic development. MCL is characterized by dysregulated expression of cyclin D1 through a chromosome t(11;14) translocation. MCL international prognostic index (MIPI), ki-67 proliferation index, and TP53 mutation status are currently utilized for prognostication. With advances in pharmacokinetic analysis and drug discovery, treatment strategy has evolved from chemotherapy to combination of targeted, epigenetic, and immune therapies. In this review, we discuss investigational and newly approved treatment approaches. In a short time, the US Food and Drug Administration (FDA) has approved five agents for the treatment of MCL: lenalidomide, an immunomodulatory agent; bortezomib, a proteasome inhibitor; and ibrutinib, acalabrutinib, and zanubrutinib, all Bruton kinase inhibitors. Epigenetic agents (e.g. cladribine and vorinostat), mammalian target of rapamycin (mTOR) inhibitors (e.g. temsirolimus and everolimus), and monoclonal antibodies and/or antibody-drug conjugates (e.g. obinutuzumab, polatuzumab, and ublituximab) are promising therapeutic agents currently under clinical trial investigation. Most recently, chimeric antigen receptor (CAR)-T cell therapy and bispecific T-cell engager (BiTE) therapy even open a new venue for MCL treatment. However, due to its intricate pathology nature and high relapse incidence, there are still unmet needs in developing optimal therapeutic strategies for both frontline and relapsed/refractory settings. The ultimate goal is to develop innovative personalized combination therapy approaches for the purpose of delivering precision medicine to cure this disease.

Is There Still a Role for Transplant for Patients with Mantle Cell Lymphoma (MCL) in the Era of CAR-T Cell Therapy?

OPINION STATEMENT

For years, upfront autologous hematopoietic cell transplant (auto-HCT) has been the standard of care for younger and physically fit mantle cell lymphoma (MCL) patients after chemoimmunotherapy (CIT) induction. Bruton's tyrosine kinase (BTK) inhibitors have proven to be excellent salvage therapies, but their durability remains a question, especially in high-risk (HR) MCL. Allogeneic HCT (allo-HCT) was the only option for long-term remission and possibly cure for MCL relapse after auto-HCT and sometime as upfront consolidation for a young patient with HR MCL (debatable). We have seen a paradigm shift since the FDA approval in July 2020 of the brexucabtagene autoleucel chimeric antigen receptor T (CAR-T) cell therapy for relapsed and refractory (R/R) MCL with an preliminary evidence suggesting CAR-T may overcome known biological risk factors in MCL. Given its safety profile and excellent efficacy, the role of CAR-T among other approved therapies and HCT may need to be better defined. Based on the current evidence, auto-HCT remains a standard frontline consolidation therapy. CAR-T therapy is a preferred option for patients with relapsed/refractory (R/R) MCL, particularly those who failed BTK inhibitors. In certain high-risk MCL patients (such as high ki 67, TP53 alterations, complex karyotype, blastoid morphology, early relapse after initial diagnosis), CAR-T cell therapy may be considered before BTK inhibitors (preferably on a clinical trial). The role of allo-HCT is unclear in the CAR-T era, but remains a viable option for eligible patients who have no access or who have failed CAR-T therapy. Our review discusses current standards and the shifting paradigms in the indications for HCT and the role of CAR-T cell therapy for MCL. Prospective studies tailored based on risk factors are needed to better define the optimal sequences of HCT and cellular therapy and other approved novel therapies.