Evolving frontline immunochemotherapy for mantle cell lymphoma and the impact on survival outcomes

Front-line and second-line treatment for mantle cell lymphoma in clinical practice: A multicenter retrospective analysis

BACKGROUND

There are few reports of clinical practice treatment patterns and efficacy in mantle cell lymphoma (MCL).

MATERIALS AND METHODS

We retrospectively studied a large, multicenter, cohort of patients with MCL diagnosed between 2000 and 2020 in eight institutions.

RESULTS

536 patients were registered (73% male, median of 70 years). Front-line treatment was based on high-dose cytarabine, bendamustine, and anthracyclines in 42%, 12%, and 15%, respectively. The median PFS for all patients was 45 months; 68, 34, and 30 months for those who received high-dose cytarabine-based, bendamustine-based and anthracycline-based therapy. 204 patients received second-line. Bendamustine-based treatment was the most common second-line regimen (36% of patients). The median second-line PFS (sPFS) for the entire cohort was 14 months; 19, 24, and 31 for bendamustine-, platinum-, and high-dose cytarabine-based regimens, with broad confidence intervals for these latter estimates. Patients treated with cytarabine-based therapies in the front-line and those with front-line PFS longer than 24 months had a substantially superior sPFS.

CONCLUSION

Front-line treatment in this cohort of MCL was as expected and with a median PFS of over 3.5 years. Second-line treatment strategies were heterogeneous and the median second-line PFS was little over 1 year.

Dismantling relapsed/refractory mantle cell lymphoma

Despite recent therapeutic advancements in the general field of non-Hodgkin lymphoma, effective treatment of relapsed or refractory (R/R) mantle cell lymphoma (MCL) remains a challenge. The development of Bruton tyrosine kinase (BTK) inhibitors has revolutionized the field and these agents are now the mainstay of R/R MCL management. However, BTK inhibitors are not curative, and as they are increasingly being incorporated into frontline regimens, the shifting treatment landscape for R/R disease presents new challenges. Here we review data for commonly employed treatment strategies including BTK inhibitors, the BCL2-inhibitor venetoclax, lenalidomide-based regimens, and chimeric antigen receptor T-cell therapy. We additionally review data for promising novel agents including antibody-drug conjugates and bispecific antibodies before highlighting some emerging targeted agents that continue to bring promise for improved outcomes in R/R MCL.

SOHO State of the Art Updates and Next Questions: Treatment Evolution of Mantle Cell Lymphoma: Navigating the Different Entities and Biological Heterogeneity of Mantle Cell Lymphoma in 2024

Progress in mantle cell lymphoma (MCL) has led to significant improvement in outcomes of patients even in the real world (RW) setting albeit to a lesser degree. In parallel to the demonstration of benefit using combination therapy with rituximab plus high-dose cytarabine (R-AraC) as well as dose intensive therapy-autologous stem cell transplantation (DIT-ASCT) consolidation and maintenance, it became clear over the last 2 decades that MCL is a highly heterogenous disease at the molecular level, explaining differences observed in clinical behavior and response to therapy. While clinical prognostic factors and models have helped stratify patients with distinct outcomes, they failed to help guide therapy. The identification of molecular high-risk (HR) features, in particular, but not only, p53 aberrations (including mutations and deletions [del]), as well as complex karyotype (CK), has allowed to identify subsets of patients with poorer outcomes (median overall survival [OS] <2 years) regardless of conventional therapies used. The constant pattern of relapse seen in MCL has fueled sustained and productive efforts, with 7 novel agents approved in the United States (US), showing high and durable efficacy even in HR and chemo-refractory patients and likely curing a subset of patients in the relapsed or refractory (R/R) setting. Progress in diagnostics, in particular next-generation sequencing (NGS), which is accessible in routine practice nowadays, can help recognize patients with HR features, well beyond MIPI or Ki-67 prognostication, although the impact on decision making is still unclear. The era of integrating novel agents into our prior standard of care (SOC) has begun with a confirmed benefit, for example, ibrutinib (Ib) in the TRIANGLE study, defining the first new potential SOC in younger patients in over 30 years. Expanding on novel agents, either in combination, sequentially or to replace chemotherapy altogether, using biological doublets or triplets has led to a median progression-free survival (PFS) in excess of 72 months, certainly competitive with prior SOC and will continue to reshape the management of MCL patients. Achieving minimal residual disease negative (MRD-ve) status is becoming a new endpoint in MCL, and customizing maintenance and/or de-escalation/consolidation strategies is within reach, although it will require prospective, built-in MRD-based approaches, with the goal of eliminating subclinical disease and not simply delaying time to relapse. Taking into account the biological diversity of MCL is now feasible in routine clinical practice and has already helped recognize what not to do for HR patients (i.e., avoid intensive induction chemotherapy and/or ASCT for p53 mutated patients) as well as identify promising novel options. Ongoing and future work will help expand on these dedicated approaches, to further improve the management and outcomes of all MCL patients.

Evolving treatment patterns and improved outcomes in relapsed/refractory mantle cell lymphoma: a prospective cohort study

Over the last two decades, the frontline therapy for mantle cell lymphoma (MCL) has evolved. However, the impact of subsequent lines of therapy on survival outcomes has not been well characterized. In this study, we investigated the treatment patterns and survival outcomes in patients with relapsed/refractory (R/R) MCL treated with second-line (2 L) therapy. Adult patients with newly diagnosed MCL from 2002 to 2015 were enrolled in a prospective cohort study. Clinical characteristics, 2 L treatment details, and outcomes were compared between patients who received 2 L treatment between 2003-2009 (Era 1), 2010-2014 (Era 2), and 2015-2021 (Era 3). 2 L treatment was heterogenous in all eras, and there was a substantial shift in the pattern of 2 L therapy over time. The estimated 2-year EFS rate was 21% (95% CI, 13-35), 40% (95% CI, 30-53), and 51% (95% CI, 37-68) in Era 1-3 respectively, and the 5-year OS rate was 31% (95% CI, 21-45), 37% (95% CI, 27-50), and 67% (95% CI, 54-83) in Era 1-3, respectively. These results provide real-world evidence on evolving treatment patterns of 2 L therapy based on the era of relapse. The changes in 2 L treatment correlated with improved EFS and OS, suggesting that treatment advances are associated with improved outcomes in patients with R/R MCL.

Clinical outcome of Mantle Cell Lymphoma patients with high-risk disease (high-risk MIPI-c or high p53 expression)

Currently, treatment allocation of patients with Mantle Cell Lymphoma (MCL) is mainly based on age and medical fitness. The combined MCL International Prognostic Index (MIPI-c) allows to predict prognosis using clinical factors (MIPI) and the Ki-67 index. However, high p53 expression as surrogate for TP53 alterations has demonstrated to be an independent predictor for poor outcome. We aimed to define a clear high-risk group based on the combination of MIPI, Ki-67 and p53 expression/TP53 alteration. A total of 684 patients from the prospective European MCL-Younger and MCL-Elderly trials were evaluable. The classification of high-risk disease (HRD) as high-risk MIPI-c or p53 expression >50% versus low-risk disease (LRD) as low, low-intermediate or high-intermediate MIPI-c and p53 expression ≤50% allowed to characterize two distinct groups with highly divergent outcome. Patients with HRD had significantly shorter median failure-free survival (FFS) (1.1 vs. 5.6 years, p < 0.0001) and overall survival (OS) (2.2 vs. 13.2 years, p < 0.0001) compared to those with LRD. These major differences were confirmed in two validation cohorts from the Italian MCL0208 and the Nordic-MCL4 trials. The results suggest that this subset of HRD patients is not sufficiently managed with the current standard treatment and is asking for novel treatment strategies.

Late effects in patients with mantle cell lymphoma treated with or without autologous stem cell transplantation

Studies on late effects in patients with mantle cell lymphoma (MCL) are becoming increasingly important as survival is improving, and novel targeted drugs are being introduced. However, knowledge about late effects is limited. The aim of this population-based study was to describe the magnitude and panorama of late effects among patients treated with or without high-dose chemotherapy with autologous stem cell transplantation (HD-ASCT). The study cohort included all patients with MCL, recorded in the Swedish Lymphoma Register, aged 18 to 69 years, diagnosed between 2000 and 2014 (N = 620; treated with HD-ASCT, n = 247) and 1:10 matched healthy comparators. Patients and comparators were followed up via the National Patient Register and Cause of Death Register, from 12 months after diagnosis or matching to December 2017. Incidence rate ratios of the numbers of outpatient visits, hospitalizations, and bed days were estimated using negative binomial regression models. In relation to the matched comparators, the rate of specialist and hospital visits was significantly higher among patients with MCL. Patients with MCL had especially high relative risks of infectious, respiratory, and blood disorders. Within this observation period, no difference in the rate of these complications, including secondary neoplasms, was observed between patients treated with and without HD-ASCT. Most of the patients died from their lymphoma and not from another cause or treatment complication. Taken together, our results imply that most of the posttreatment health care needs are related to the lymphoma disease itself, thus, indicating the need for more efficient treatment options.

Tumor Microenvironment and Immunotherapy-Based Approaches in Mantle Cell Lymphoma

Mantle cell lymphoma (MCL) is an aggressive B-cell non-Hodgkin lymphoma (NHL) characterized by the translocation t(11;14) (q13;q32) and a poor response to rituximab–anthracycline-based chemotherapy. High-dose cytarabine-based regimens offer a durable response, but an important number of MCL patients are not eligible for intensive treatment and are ideal candidates for novel targeted therapies (such as BTK, proteasome or BCL2 inhibitors, Immunomodulatory Drugs (IMiDs), bispecific antibodies, or CAR-T cell therapy). On the bench side, several studies aiming to integrate the tumor within its ecosystem highlighted a critical role of the tumor microenvironment (TME) in the expansion and resistance of MCL. This led to important insights into the role of the TME in the management of MCL, including potential targets and biomarkers. Indeed, targeted agents often have a combined mechanism of action on the tumor B cell but also on the tumor microenvironment. The aim of this review is to briefly describe the current knowledge on the biology of the TME in MCL and expose the results of the different therapeutic strategies integrating the TME in this disease.

Mantle Cell Lymphoma: the Role of Risk-Adapted Therapy and Treatment of Relapsed Disease

PURPOSE OF REVIEW

In this review, the current treatment strategies are recapped, evolving agents are discussed, and we provide guidance in treating R/R MCL.

RECENT FINDINGS

There has been an advancement in treatment using targeted therapy, cellular therapies including chimeric antigen receptor (CAR) T cell therapy and hematopoietic stem cell transplantation (HSCT) and novel therapeutic agents including non-covalent BTKis, bispecific antibodies, and antibody-drug conjugates for treatment of refractory and relapsed mantle cell lymphoma. Mantle cell lymphoma (MCL) is a mature B-cell lymphoma that is associated with a poor prognosis. Current treatments include immunochemotherapy, chemotherapy and autologous stem cell transplantation (SCT) which place patients in remission but result in relapse. Chemoimmunotherapy uses chemotherapeutic agents paired with rituximab in patients who have chemo-sensitive disease with prolonged remission of at least > 2 years and/or have contraindications to chemotherapy that serve as bridges to more definitive treatment. Additional therapies including proteosome inhibitor-based therapies and immunomodulators, like bortezomib and lenalidomide, can be used as single agents or in combination with others. Bruton's tyrosine kinase (BTK) inhibitors including ibrutinib, acalaburtinib, and zanubrutinib have also been proven effective for the treatment of (R/R) disease. Another agent is Venetoclax, a robust drug that can be used in MCL after progression or intolerance to BTKi. Newer advances in the management of MCL have led to the utilization of cellular therapies including chimeric antigen receptor (CAR) T cell therapy and SCT that are options for healthy young (< 65 years old) who have progressed through several lines of therapies. With progression of disease, mutations are acquired that cause therapy resistance. Novel therapeutic agents such as non-covalent BTKis, bispecific antibodies, and antibody-drug conjugates are paving the way for advancements in treatment for R/R MCL. R/R MCL is a complex disease with many therapeutic options none of which has been proven superior in head-to-head comparison. In this review, the current treatment strategies are recapped, evolving agents are discussed, and we provide guidance in treating R/R MCL.

Mantle cell lymphoma in 2022-A comprehensive update on molecular pathogenesis, risk stratification, clinical approach, and current and novel treatments

The field of mantle cell lymphoma (MCL) has witnessed remarkable progress due to relentless advances in molecular pathogenesis, prognostication, and newer treatments. MCL consists of a spectrum of clinical subtypes. Rarely, atypical cyclin D1-negative MCL and in situ MCL neoplasia are identified. Prognostication of MCL is further refined by identifying somatic mutations (such as TP53, NSD2, KMT2D), methylation status, chromatin organization pattern, SOX-11 expression, minimal residual disease (MRD), and genomic clusters. Lymphoid tissue microenvironment studies demonstrated the role of B-cell receptor signaling, nuclear factor kappa B (NF-kB), colony-stimulating factor (CSF)-1, the CD70-SOX-11 axis. Molecular mechanism of resistance, mutation dynamics, and pathogenic pathways (B-cell receptor (BCR), oxidative phosphorylation, and MYC) were identified in mediating resistance to various treatments (bruton tyrosine kinase (BTK) inhibitors [ibrutinib, acalabrutinib]. Treatment options range from conventional chemoimmunotherapy and stem cell transplantation (SCT) to targeted therapies against BTK (covalent and noncovalent), Bcl2, ROR1, cellular therapy such as anti-CD19 chimeric antigen receptor therapy (CAR-T), and most recently bispecific antibodies against CD19 and CD20. MCL patients frequently relapse. Complex pathogenesis and the management of patients with progression after treatment with BTK/Bcl2 inhibitors and CAR-T (triple-resistant MCL) remain a challenge. Next-generation clinical trials incorporating newer agents and concurrent translational and molecular investigations are ongoing.