Brexucabtagene autoleucel for relapsed or refractory mantle cell lymphoma in the United Kingdom: A real-world intention-to-treat analysis

Brexucabtagene autoleucel (brexu-cel) is an autologous CD19 CAR T-cell product, approved for relapsed/refractory (r/r) mantle cell lymphoma (MCL). In ZUMA-2, brexu-cel demonstrated impressive responses in patients failing ≥2 lines, including a bruton's tyrosine kinase inhibitor, with an overall and complete response rate of 93% and 67%, respectively. Here, we report our real-world intention-to-treat (ITT) outcomes for brexu-cel in consecutive, prospectively approved patients, from 12 institutions in the United Kingdom between February 2021 and June 2023, with a focus on feasibility, efficacy, and tolerability. Of 119 approved, 104 underwent leukapheresis and 83 received a brexu-cel infusion. Progressive disease (PD) and/or manufacturing (MF) were the most common reasons for failure to reach harvest and/or infusion. For infused patients, best overall and complete response rates were 87% and 81%, respectively. At a median follow-up of 13.3 months, median progression-free survival (PFS) for infused patients was 21 months (10.1-NA) with a 6- and 12-month PFS of 82% (95% confidence interval [CI], 71-89) and 62% (95% CI, 49-73), respectively. ≥Grade 3 cytokine release syndrome and neurotoxicity occurred in 12% and 22%, respectively. On multivariate analysis, inferior PFS was associated with male sex, bulky disease, ECOG PS > 1 and previous MF. Cumulative incidence of non-relapse mortality (NRM) was 6%, 15%, and 25% at 6, 12, and 24 months, respectively, and mostly attributable to infection. Outcomes for infused patients in the UK are comparable to ZUMA-2 and other real-world reports. However, ITT analysis highlights a significant dropout due to PD and/or MF. NRM events warrant further attention.

TP53 mutation is frequent in mantle cell lymphoma with EZH2 expression and have dismal outcome when both are present

Enhancer of zeste homolog 2 (EZH2) expression is found in about 40% of mantle cell lymphoma (MCL) patients, which is associated with aggressive histology, high Ki-67 proliferation rate, p53 mutant pattern and inferior overall survival (OS). We conducted 11-gene (ATM, BIRC3, CCND1, KMT2C, KMT2D, NOTCH1, NOTCH2, RB1, TP53, TRAF2 and UBR5) next generation sequencing panel to shed more light on MCL with EZH2 expression (EZH2+ MCL). EZH2+ MCL more frequently harbor TP53 mutation compared to EZH2(-) MCL (41.2% vs. 19.1%, respectively, p = 0.045). TP53 mutation and EZH2 expression demonstrated overlapping features including aggressive histology, high Ki-67 proliferation rate and p53 mutant pattern by immunohistochemistry. Comparative analysis disclosed that EZH2 expression correlates with high Ki-67 proliferation rate irrespective of TP53 mutation. Aggressive histology is associated with EZH2 expression or TP53 mutation, possibly via independent mechanisms. p53 mutant pattern is due to TP53 mutation. MCL patients with EZH2 expression or TP53 mutation show inferior outcome and when both are present, patients have dismal outcome.

Predictive Value of Minimal Residual Disease for Efficacy of Rituximab Maintenance in Mantle Cell Lymphoma: Results From the European Mantle Cell Lymphoma Elderly Trial

PURPOSE

The outcome of older patients with mantle cell lymphoma (MCL) has improved by the introduction of immunochemotherapy, followed by rituximab (R)-maintenance. Assessment of minimal residual disease (MRD) represents a promising tool for individualized treatment decisions and was a prospectively planned part of the European MCL Elderly trial. We investigated how MRD status influenced the efficacy of R-maintenance and how MRD can enable tailored consolidation strategies.

PATIENTS AND METHODS

Previously untreated patients with MCL age 60 years or older have been randomly assigned to R versus interferon-alpha maintenance after response to rituximab, fludarabine, cyclophosphamide (R-FC) versus rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone (R-CHOP). MRD monitoring was performed by real-time quantitative polymerase chain reaction (qPCR) following EuroMRD guidelines.

RESULTS

A qPCR assay with a median sensitivity of 1 × 10-5 could be generated in 80% of 288 patients in an international, multicenter, multilaboratory setting. More extensive tumor dissemination facilitated the identification of a molecular marker. The efficacy of R-maintenance in clinical remission was confirmed for MRD-negative patients at the end of induction in terms of progression-free survival (PFS; hazard ratio [HR], 0.38 [95% CI, 0.21 to 0.63]) and overall survival (OS; HR, 0.37 [95% CI, 0.20 to 0.68]), particularly in R-CHOP-treated patients (PFS-HR, 0.23 [95% CI, 0.10 to 0.52]; OS-HR, 0.19 [95% CI, 0.07 to 0.52]). R-maintenance appeared less effective in MRD-positive patients (PFS-HR, 0.51 [95% CI, 0.26 to 1.02]) overall and after R-CHOP induction (PFS-HR, 0.59 [95% CI, 0.28 to 1.26]). R-FC achieved more frequent and faster MRD clearance compared with R-CHOP. MRD positivity in clinical remission after induction was associated with a short median time to clinical progression of approximately 1-1.7 years.

CONCLUSION

The results confirm the strong efficacy of R-maintenance in patients who are MRD-negative after induction. Treatment de-escalation for MRD-negative patients is discouraged by our results. More effective consolidation strategies should be explored in MRD-positive patients to improve their long-term prognosis.

Integrative analysis of clinicopathological features defines novel prognostic models for mantle cell lymphoma in the immunochemotherapy era: a report from The North American Mantle Cell Lymphoma Consortium

BACKGROUND

Patients with mantle cell lymphoma (MCL) exhibit a wide variation in clinical presentation and outcome. However, the commonly used prognostic models are outdated and inadequate to address the needs of the current multidisciplinary management of this disease. This study aims to investigate the clinical and pathological features of MCL in the immunochemotherapy era and improve the prognostic models for a more accurate prediction of patient outcomes.

METHODS

The North American Mantle Cell Lymphoma Project is a multi-institutional collaboration of 23 institutions across North America to evaluate and refine prognosticators for front-line therapy. A total of 586 MCL cases diagnosed between 2000 and 2012 are included in this study. A comprehensive retrospective analysis was performed on the clinicopathological features, treatment approaches, and outcomes of these cases. The establishment of novel prognostic models was based on in-depth examination of baseline parameters, and subsequent validation in an independent cohort of MCL cases.

RESULTS

In front-line strategies, the use of hematopoietic stem cell transplantation was the most significant parameter affecting outcomes, for both overall survival (OS, p < 0.0001) and progression-free survival (PFS, p < 0.0001). P53 positive expression was the most significant pathological parameter correlating with inferior outcomes (p < 0.0001 for OS and p = 0.0021 for PFS). Based on the baseline risk factor profile, we developed a set of prognostic models incorporating clinical, laboratory, and pathological parameters that are specifically tailored for various applications. These models, when tested in the validation cohort, exhibited strong predictive power for survival and showed a stratification resembling the training cohort.

CONCLUSIONS

The outcome of patients with MCL has markedly improved over the past two decades, and further enhancement is anticipated with the evolution of clinical management. The innovative prognostic models developed in this study would serve as a valuable tool to guide the selection of more suitable treatment strategies for patients with MCL.

The addition of rituximab to chemotherapy improves overall survival in mantle cell lymphoma-a pooled trials analysis

Mantle cell lymphoma (MCL) is a distinct subtype of B-cell lymphoma and commonly used induction immunochemotherapies include the anti-CD20 antibody rituximab. However, efficacy data for rituximab regarding overall survival (OS) in first line MCL therapy remain conflicting.We report long-term outcomes of a pooled trials analysis comparing Cyclophosphamide, Doxorubicine, Vincristine, Prednisone (CHOP) to R-CHOP in MCL to confirm efficacy on failure free survival (FFS) and OS in relevant subgroups. Untreated, adult MCL patients of two prospective trials assigned to CHOP or R-CHOP were included. Primary endpoints were FFS and OS, secondary endpoints included duration of response (DOR), secondary malignancies and OS after relapse. Between 1996 and 2003, 385 MCL patients were assigned to CHOP (201) or R-CHOP (184). After a median follow-up of 13.4 years, the addition of Rituximab significantly improved FFS (1.36 vs. 2.07 years, HR 0.62 (0.50-0.77)), OS (4.84 vs. 5.81 years, HR 0.78 (0.61-0.99)) and DOR (1.48 vs. 2.08 years, HR 0.67 (0.53-0.86)). Furthermore, Rituximab improved survival across different MCL risk groups. In a post-hoc analysis of OS after relapse comparing patients receiving chemotherapy with / without rituximab, rituximab maintained efficacy with a median OS of 3.10 vs. 2.11 years (HR 0.70, 0.54-0.91). The rate of secondary malignancies was 0.5 and 3.9% for hematological and 7 and 8% for non-hematological malignancies for CHOP and R-CHOP patients, respectively. We present mature results of a pooled MCL cohort, demonstrating prolonged FFS, OS and DOR for the combined immuno-chemotherapy, confirming the standard of care in first line treatment.

The prognostic role of gene polymorphisms in patients with indolent non-Hodgkin lymphomas and mantle-cell lymphoma receiving bendamustine and rituximab: results of the 5-year follow-up study

The variability in disease outcome for indolent non-Hodgkin lymphomas (iNHL) and mantle-cell lymphoma (MCL) could be related to single nucleotide polymorphisms (SNPs) in genes that affect immune and inflammatory response. We investigated SNPs that could have a prognostic role for patients receiving bendamustine and rituximab (BR). All samples were genotyped for the IL-2 (rs2069762), IL-10 (rs1800890, rs10494879), VEGFA (rs3025039), IL-8 (rs4073), CFH (rs1065489) and MTHFR (rs1801131) SNPs by allelic discrimination assays using TaqMan SNP Genotyping Assays. We report a long-term follow-up analysis of 79 iNHL and MCL patients that received BR. Overall response rate was 97.5% (CR rate 70.9%). After a median follow-up of 63 months, median PFS and OS were not reached. We report a significant association between SNP in IL-2 (rs2069762) and reduced PFS and OS (p<.0001). We suggest a role for cytokine SNPs in disease outcome, while SNPs seem not related to long-term toxicity or secondary malignancies.

SOHO State of the Art Updates and Next Questions: Tailoring Upfront Therapy in Mantle Cell Lymphoma

In this article, we will review current strategies for the front-line management of mantle cell lymphoma, an uncommon and biologically and clinically heterogeneous subtype of non-Hodgkin lymphoma that remains incurable with current therapies. Patients invariably relapse with time, and as a result, treatment strategies involve persistent therapy over the course of months to years, including induction, consolidation, and maintenance. Topics discussed include the historical development of various chemoimmunotherapy backbones with continued modifications to maintain and improve efficacy while limiting off-target, off-tumor effects. Chemotherapy-free induction regimens were developed initially for elderly or less fit patients though are now being utilized for younger, transplant-eligible patients due to deeper, more prolonged remission durations with fewer toxicities. The historic paradigm of recommending autologous hematopoietic cell transplant for fit patients in complete or partial remission is now being challenged based in part on ongoing clinical trials in which minimal residual disease directed approaches influence the consolidation strategy for any particular individual. The addition of novel agents, namely first and second generation Bruton tyrosine kinase inhibitors as well as immunomodulatory drugs, BH3 mimetics, and type II glycoengineered anti-CD20 monoclonal antibodies have been tested in various combinations with or without immunochemotherapy. We will attempt to help the reader by systematically explaining and simplifying the various approaches for treating this complicated group of disorders.

Integrative Prognostic Machine Learning Models in Mantle Cell Lymphoma

Patients with mantle cell lymphoma (MCL), an incurable B-cell malignancy, benefit from accurate pretreatment disease stratification. We curated an extensive database of 862 patients diagnosed between 2014 and 2022. A machine learning (ML) gradient-boosted model incorporated baseline features from clinicopathologic, cytogenetic, and genomic data with high predictive power discriminating between patients with indolent or responsive MCL and those with aggressive disease (AUC ROC = 0.83). In addition, we utilized the gradient-boosted framework as a robust feature selection method for multivariate logistic and survival modeling. The best ML models incorporated features from clinical and genomic data types highlighting the need for correlative molecular studies in precision oncology. As proof of concept, we launched our most accurate and practical models using an application interface, which has potential for clinical implementation. We designated the 20-feature ML model-based index the "integrative MIPI" or iMIPI and a similar 10-feature ML index the "integrative simplified MIPI" or iMIPI-s. The top 10 baseline prognostic features represented in the iMIPI-s are: lactase dehydrogenase (LDH), Ki-67%, platelet count, bone marrow involvement percentage, hemoglobin levels, the total number of observed somatic mutations, TP53 mutational status, Eastern Cooperative Oncology Group performance level, beta-2 microglobulin, and morphology. Our findings emphasize that prognostic applications and indices should include molecular features, especially TP53 mutational status. This work demonstrates the clinical utility of complex ML models and provides further evidence for existing prognostic markers in MCL.

Significance

Our model is the first to integrate a dynamic algorithm with multiple clinical and molecular features, allowing for accurate predictions of MCL disease outcomes in a large patient cohort.

Exploring new prognostic biomarkers in Mantle Cell Lymphoma: a comparison of the circSCORE and the MCL35 score

Mantle cell lymphoma (MCL) is a biologically and clinically heterogeneous disease, emphasizing the need for prognostic biomarkers. In this study we aimed at comparing the prognostic value of two RNA-based risk scores, circSCORE and MCL35, in 149 patients from the MCL2 (ISRCTN87866680) and MCL3 (NCT00514475) patient cohorts. Both risk scores provided significant stratification of high versus low risk for progression free survival (PFS) and overall survival (OS). The circSCORE retained significant prognostic value in adjusted multivariable Cox regressions for PFS, but not for OS. Furthermore, circSCORE added significant prognostic value to MIPI in the pooled cohort (MCL2 and MCL3) for PFS and OS, and for PFS in MCL3 alone, outperforming Ki67 and MCL35. We suggest a new, combined MIPI-circSCORE with improved prognostic value, and with potential for future clinical implementation, if validated in a larger, independent cohort.

Brexucabtagene Autoleucel for Relapsed or Refractory Mantle Cell Lymphoma in Standard-of-Care Practice: Results From the US Lymphoma CAR T Consortium

PURPOSE

Brexucabtagene autoleucel (brexu-cel) is an autologous CD19-directed chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory mantle cell lymphoma (MCL). This therapy was approved on the basis of the single-arm phase II ZUMA-2 trial, which showed best overall and complete response rates of 91% and 68%, respectively. We report clinical outcomes with brexu-cel in the standard-of-care setting for the approved indication.

PATIENTS AND METHODS

Patients who underwent leukapheresis between August 1, 2020 and December 31, 2021, at 16 US institutions, with an intent to manufacture commercial brexu-cel for relapsed/refractory MCL, were included. Patient data were collected for analyses of responses, outcomes, and toxicities as per standard guidelines.

RESULTS

Of 189 patients who underwent leukapheresis, 168 (89%) received brexu-cel infusion. Of leukapheresed patients, 79% would not have met ZUMA-2 eligibility criteria. Best overall and complete response rates were 90% and 82%, respectively. At a median follow-up of 14.3 months after infusion, the estimates for 6- and 12-month progression-free survival (PFS) were 69% (95% CI, 61 to 75) and 59% (95% CI, 51 to 66), respectively. The nonrelapse mortality was 9.1% at 1 year, primarily because of infections. Grade 3 or higher cytokine release syndrome and neurotoxicity occurred in 8% and 32%, respectively. In univariable analysis, high-risk simplified MCL international prognostic index, high Ki-67, TP53 aberration, complex karyotype, and blastoid/pleomorphic variant were associated with shorter PFS after brexu-cel infusion. Patients with recent bendamustine exposure (within 24 months before leukapheresis) had shorter PFS and overall survival after leukapheresis in intention-to-treat univariable analysis.

CONCLUSION

In the standard-of-care setting, the efficacy and toxicity of brexu-cel were consistent with those reported in the ZUMA-2 trial. Tumor-intrinsic features of MCL, and possibly recent bendamustine exposure, may be associated with inferior efficacy outcomes.

PAX5 aberrant expression incorporated in MIPI-SP risk scoring system exhibits additive value in mantle cell lymphoma

Mantle cell lymphoma (MCL) is a subtype of non-Hodgkin lymphoma with highly heterogeneous clinical courses. Paired-box 5 (PAX5), the regulator of B cell differentiation and growth, is abnormally expressed in several types of cancers. Herein, we explored the prognostic value of PAX5 in MCL by comprehensively analyzing the clinical features and laboratory data of 82 MCL cases. PAX5 positivity was associated with shorter overall survival (OS; p = 0.011) and was identified as an independent prognostic factor in MCL patients. The elevated β2-MG (p = 0.027) and advanced Mantle Cell Lymphoma International Prognostic Index (MIPI) score (p = 0.014) were related to positive PAX5 expression. The MIPI-SP risk scoring system was established and exhibited a superior prognostic value for OS depending on an area under the curve (AUC) of 0.770 (95% CI, 0.658-0.881) than MIPI score. Bioinformatic analysis of PAX5-related genes supported the mechanistic roles of PAX5 in MCL. This study provides insight into the potential role of PAX5 in MCL, and the novel risk scoring system MIPI-SP optimizes the risk stratification and facilitates prognosis evaluation in MCL patients. KEY MESSAGES: • Paired-box 5 positivity indicated adverse prognosis in mantle cell lymphoma patients. • Positive PAX5 expression was related to MIPI score and β2-MG in MCL patients. • MIPI-SP risk scoring system has superior prognostic value than MIPI score in MCL.

Evaluation of Bortezomib-BeEAM (2BeEAM) as Chemotherapy Regimen Prior to ASCT in Patients with Mantle Cell Lymphoma

(1) Background: First-line therapy in fit MCL patients may comprise high-dose chemotherapy (HDCT) with autologous transplantation to consolidate remission before maintenance treatment. However, optimization of HDCT is an unmet clinical need given the substantial relapse rate of first-line treatment, while the use of bortezomib is a promising candidate to be added to standard HDCT. (2) Methods: We analyzed 11 consecutive patients with MCL who received bortezomib added to standard BeEAM (2BeEAM) HDCT at a single academic institution. We assessed safety, feasibility, toxicities, and survival rates. (3) Results: All patients had stage III or IV disease. We found that six patients (55%) developed new or worsening of preexisting peripheral neuropathy following administration of 2BeEAM HDCT. One patient relapsed within the first six months after HDCT, whereas three patients never reached complete remission. After a median follow-up of 22 months, the PFS was 64% and the OS 64% at the last follow-up assessment. At this time, 55% of patients were in CR. (4) Conclusions: The use of bortezomib added to standard BeEAM HDCT is associated with relevant toxicities, particularly with regards to additional neuropathy. Moreover, the anti-lymphoma efficacy of 2BeEAM HDCT appears to be modest; therefore, other therapeutic options should be evaluated for consolidation in this patient group.

Personalized approaches for treatment-naïve mantle cell lymphoma

INTRODUCTION

Mantle cell lymphoma (MCL) can have diverse disease presentations, which vary in aggressiveness and prognosis, and can occur in patients with varying ability to tolerate therapy. Additionally, the options for treatment of MCL have expanded rapidly in the last decade, translating to improved outcome for patients.

AREAS COVERED

We review the initial evaluation of patients with MCL, identifying disease- and patient-specific prognostic factors, along with personalized therapies for patients with MCL. Specific scenarios include indolent and limited-stage MCL, advanced-stage disease in transplant-eligible and ineligible patients, and high-risk TP53 mutant disease. Ongoing trials and future directions in MCL treatment are also highlighted.

EXPERT OPINION

Given the wide array of disease and patient presentations with MCL, a personalized therapeutic approach is needed to optimize outcomes. The best therapeutic strategy should incorporate disease prognostic factors, patient status and comorbidities, goals of care, and response to treatment.

Ibrutinib in mantle cell lymphoma: a real-world retrospective multi-center analysis of 77 patients treated in the Czech Republic

Ibrutinib revolutionized therapy for relapsed/refractory (R/R) mantle cell lymphoma (MCL). Real-world data on the outcome of unselected patients are still limited. We analyzed 77 R/R MCL patients receiving ibrutinib with at least one prior systemic anti-lymphoma therapy. After a median follow-up of 14.0 months, 56 patients relapsed/progressed, and 45 died. The overall response rate was 66%, with 31% of complete metabolic remissions on PET/CT. The median progression-free and overall survival (OS) rates were 10.3 and 23.1 months, respectively. The median OS from ibrutinib failure was 3.7 months. High proliferation rate by Ki67 (≥ 30%) and two or more previous therapy lines both negatively correlated with outcome (HR = 2.2, p = 0.04, and HR = 2.06, p = 0.08, respectively). Female gender borderline correlated with better outcome (HR = 0.53, p = 0.08). In multivariate analysis, Ki67 and response to ibrutinib both correlated with OS (p < 0.05). Importantly, ibrutinib appeared to better control nodal and extranodal lymphoma than bone marrow (BM) involvement. From 20 patients with detectable BM infiltration (before ibrutinib initiation) achieving complete (n = 13) or partial (n = 7) metabolic remission, none achieved remission in BM. We confirmed good efficacy of ibrutinib in unselected heavily pre-treated MCL patients. Our findings support the use of a combination of ibrutinib and rituximab in patients with BM involvement.

Molecular determinants of outcomes in relapsed or refractory mantle cell lymphoma treated with ibrutinib or temsirolimus in the MCL3001 (RAY) trial

Mantle cell lymphoma (MCL) is a rare, incurable lymphoma subtype characterized by heterogeneous outcomes. To better understand the clinical behavior and response to treatment, predictive biomarkers are needed. Using residual archived material from patients enrolled in the MCL3001 (RAY) study, we performed detailed analyses of gene expression and targeted genetic sequencing. This phase III clinical trial randomized patients with relapsed or refractory MCL to treatment with either ibrutinib or temsirolimus. We confirmed the prognostic capability of the gene expression proliferation assay MCL35 in this cohort treated with novel agents; it outperformed the simplified MCL International Prognostic Index in discriminating patients with different outcomes. Regardless of treatment arm, our data demonstrated that this assay captures the risk conferred by known biological factors, including increased MYC expression, blastoid morphology, aberrations of TP53, and truncated CCND1 3' untranslated region. We showed the negative impact of BIRC3 mutations/deletions on outcomes in this cohort and identified that deletion of chromosome 8p23.3 also negatively impacts survival. Restricted to patients with deletions/alterations in TP53, ibrutinib appeared to abrogate the deleterious impact on outcome. These data illustrate the potential to perform a molecular analysis of predictive biomarkers on routine patient samples that can meaningfully inform clinical practice.

Treatment of Mantle Cell Lymphoma in the Frontline Setting: Are We Ready for a Risk-Adapted Approach?

Mantle cell lymphoma (MCL), a type of B-cell non-Hodgkin lymphoma characterized by the t(11;14)(q13q32) translocation, is a clinically heterogenous disease which can range from indolent to highly aggressive. Numerous prognostic factors have been identified, including blastoid histology, the Mantle Cell Lymphoma International Prognostic Index (MIPI) score, high proliferation index, p53 deletions and/or mutations, complex karyotype, minimal residual disease, and several others. However, using these prognostic factors to guide treatment selection has largely remained elusive. Given the heterogeneous behavior of this disease and varying patient characteristics, we suggest that the time has come for a more risk-adapted approach to this disease. In this article, we review the numerous prognostic factors that have been described for MCL, both at the time of diagnosis and following first-line treatment. We then propose a risk-adapted approach to first-line therapy for MCL, which would reserve intensive therapy for the highest risk patients and spare others excessive toxicity.

New Directions for Mantle Cell Lymphoma in 2022

Mantle cell lymphoma is a rare B-cell non-Hodgkin lymphoma that is clinically and biologically heterogeneous. Risk stratification at the time of diagnosis is critical. One of the most powerful prognostic indices is the Mantle Cell Lymphoma International Prognostic Index-Combined, which integrates an estimate of proliferation (Ki67 index) with the standard Mantle Cell Lymphoma International Prognostic Index clinical factors. In addition, the presence of TP53 mutation is associated with suboptimal response to intensive chemoimmunotherapy and particularly dismal survival outcomes. Given their excellent activity in the relapsed/refractory setting, increasingly, biologically targeted therapeutics-such as covalent Bruton tyrosine kinase inhibitors, lenalidomide, and venetoclax-are being incorporated into "chemotherapy-free" regimens and in combination with established chemoimmunotherapy backbones for treatment-naïve mantle cell lymphoma. In addition, risk-adapted treatment programs are increasingly being studied. These programs tailor treatment according to baseline prognostic factors (e.g., presence of TP53 mutation) and may incorporate biomarkers of response such as minimal residual disease assessment. Although still investigational, these studies present an opportunity to move beyond the biology-agnostic, historical fitness-based treatment selection paradigm and toward a more personalized, tailored treatment approach in mantle cell lymphoma. After Bruton tyrosine kinase inhibitor failure, many promising standard or investigational therapies exist, including CAR T-cell therapy (including brexucabtagene autoleucel and lisocabtagene maraleucel), bispecific antibody therapy targeting CD20-CD3, zilovertamab vedotin (an antibody-drug conjugate that targets ROR1), and the noncovalent Bruton tyrosine kinase inhibitor pirtobrutinib. These new therapies show promising efficacy, even among high-risk patients, and will likely translate to improvements in survival outcomes for patients with progressive mantle cell lymphoma following treatment with a Bruton tyrosine kinase inhibitor.

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.

A Clinical Prognostic Model Based on Machine Learning from the Fondazione Italiana Linfomi (FIL) MCL0208 Phase III Trial

Simple Summary

The interest in using Machine-Learning (ML) techniques in clinical research is growing. We applied ML to build up a novel prognostic model from patients affected with Mantle Cell Lymphoma (MCL) enrolled in a phase III open-labeled, randomized clinical trial from the Fondazione Italiana Linfomi (FIL)—MCL0208. This is the first application of ML in a prospective clinical trial on MCL lymphoma. We applied a novel ML pipeline to a large cohort of patients for which several clinical variables have been collected at baseline, and assessed their prognostic value based on overall survival. We validated it on two independent data series provided by European MCL Network. Due to its flexibility, we believe that ML would be of tremendous help in the development of a novel MCL prognostic score aimed at re-defining risk stratification.

Abstract

Background: Multicenter clinical trials are producing growing amounts of clinical data. Machine Learning (ML) might facilitate the discovery of novel tools for prognostication and disease-stratification. Taking advantage of a systematic collection of multiple variables, we developed a model derived from data collected on 300 patients with mantle cell lymphoma (MCL) from the Fondazione Italiana Linfomi-MCL0208 phase III trial (NCT02354313). Methods: We developed a score with a clustering algorithm applied to clinical variables. The candidate score was correlated to overall survival (OS) and validated in two independent data series from the European MCL Network (NCT00209222, NCT00209209); Results: Three groups of patients were significantly discriminated: Low, Intermediate (Int), and High risk (High). Seven discriminants were identified by a feature reduction approach: albumin, Ki-67, lactate dehydrogenase, lymphocytes, platelets, bone marrow infiltration, and B-symptoms. Accordingly, patients in the Int and High groups had shorter OS rates than those in the Low and Int groups, respectively (Int→Low, HR: 3.1, 95% CI: 1.0–9.6; High→Int, HR: 2.3, 95% CI: 1.5–4.7). Based on the 7 markers, we defined the engineered MCL international prognostic index (eMIPI), which was validated and confirmed in two independent cohorts; Conclusions: We developed and validated a ML-based prognostic model for MCL. Even when currently limited to baseline predictors, our approach has high scalability potential.

CD5-negative mantle cell lymphoma: clinicopathologic features of an indolent variant that confers a survival advantage

Conventionally, mantle cell lymphoma (MCL) is an aggressive CD5-positive B-cell malignancy with poor prognosis and limited survival. However, a small subset of patients presents with indolent disease and can be managed on a 'watch and wait' approach. CD5-negative MCL has recently been recognized as a more favorable variant of MCL, but its clinical and biological implications remain ill-defined. We performed the most extensive review to-date of all reported cases of CD5-negative MCL and included unpublished cases diagnosed at our institutions to further characterize this disease subset. Based on our analysis of 356 cases of CD5-negative MCL, we conclude that median overall survival exceeds 14 years and is independent of favorable prognostic markers such as leukemic non-nodal disease, absence of SOX11, and low Ki-67.

Blastoid Mantle Cell Lymphoma of the Palate: Report of a Rare Aggressive Entity and Review of the Literature

Mantle cell lymphoma (MCL) is a well-defined, non-Hodgkin lymphoma of B-cell origin displaying diverse morphological phenotypes and variable disease course. The World Health Organization recognizes two aggressive histopathologic variants of this type of lymphoma: pleomorphic and blastoid MCL. To date, only few cases of MCL affecting the oral cavity have been reported. Additionally, the involvement of the oral and maxillofacial area by aggressive MCL subsets is considered extremely rare with only two patients reported in the English language literature to the best of our knowledge. Herein, we describe a 69 year-old male with a prior history of MCL of the right lateral pharyngeal wall developing a recurrent lesion extending to the palatal mucosa as diffuse ulceration and exhibiting histomorphological features of blastoid MCL. We also review the pertinent literature with emphasis on the diagnostic challenges and distinction between the different MCL variants.

Non-chemotherapy Options for Newly Diagnosed Mantle Cell Lymphoma

OPINION STATEMENT

Mantle cell lymphoma is a rare and incurable non-Hodgkin lymphoma with a heterogenous clinical presentation. Typically, treatment consists of frontline chemoimmunotherapy induction with or without autologous stem cell transplant (ASCT) as consolidation. However, this approach has the propensity to increase short- and long-term toxicities, such as secondary malignancies, without being curative. Genomic profiling of MCL will allow for greater impact of new targeted therapies in the future and may become a helpful tool to guide treatment. Based on the data discussed, use of non-chemotherapy options may become the preferred approach for frontline therapy as opposed to conventional chemotherapy and hematopoietic stem cell transplants.

Early Relapse Identifies MCL patients with Inferior Survival after Intensive or Less Intensive Frontline Therapy

POD<24 months was associated with inferior survival among patients with MCL after both intensive and less intensive frontline treatment.

Patients with POD<6 months or progressive disease after frontline treatment had the highest risk of early mortality.

Although an expanding array of effective treatments has resulted in recent improvement in survival of patients with mantle cell lymphoma (MCL), outcomes remain heterogeneous, and identification of prognostic factors remains a priority. We assessed the prognostic impact of time to progression of disease (POD) after first-line therapy among 455 patients with relapsed MCL. Patients were categorized by duration of first remission as PRF/POD6, defined as progressive disease during induction or POD within 6 months of diagnosis (n = 65; 14%); POD6-24, defined as POD between 6 and 24 months after diagnosis (n = 153; 34%); and POD>24, defined as POD >24 months after diagnosis (n = 237; 53%). The median overall survival from POD (OS2) was 1.3 years (95% confidence interval [CI], 0.9-2.4) for patients with PRF/POD6, 3 years (95% CI, 2-6.8) for those with POD6-24, and 8 years (95% CI, 6.2-NR) for those with POD>24. Median OS2 was inferior in patients with early POD (defined as PRF/POD6 or POD6-24) after both intensive and less intensive frontline treatment. The prognostic performance of time until POD was replicated in an independent cohort of 245 patients with relapsed MCL, with median OS2 of 0.3 years (95% CI, 0.1-0.5) for PRF/POD6, 0.8 years (95% CI, 0.6-0.9) for POD6-24, and 2.4 years (95% CI 2.1-2.7) for POD>24. Early POD is associated with inferior OS2 in patients with relapsed MCL, identifying a high-risk population for future prospective studies.

American Society of Transplantation and Cellular Therapy, Center of International Blood and Marrow Transplant Research, and European Society for Blood and Marrow Transplantation Clinical Practice Recommendations for Transplantation and Cellular Therapies in Mantle Cell Lymphoma

Autologous (auto-) and allogeneic (allo-) hematopoietic cell transplantation (HCT) are accepted treatment modalities in contemporary treatment algorithms for mantle cell lymphoma (MCL). Chimeric antigen receptor (CAR) T cell therapy recently received approval for MCL; however, its exact place and sequence in relation to HCT remain unclear. The American Society of Transplantation and Cellular Therapy, Center of International Blood and Marrow Transplant Research, and the European Society for Blood and Marrow Transplantation jointly convened an expert panel to formulate consensus recommendations for role, timing, and sequencing of auto-HCT, allo-HCT, and CAR T cell therapy for patients with newly diagnosed and relapsed/refractory (R/R) MCL. The RAND-modified Delphi method was used to generate consensus statements. Seventeen consensus statements were generated, with a few key statements as follows: in the first line setting, auto-HCT consolidation represents standard of care in eligible patients, whereas there is no clear role of allo-HCT or CAR T cell therapy outside of clinical trials. In the R/R setting, the preferential option is CAR T cell therapy, especially in patients with MCL failing or intolerant to at least one Bruton's tyrosine kinase inhibitor, while allo-HCT is recommended if CAR T cell therapy fails or is infeasible. Several recommendations were based on expert opinion, where the panel developed consensus statements for important real-world clinical scenarios to guide clinical practice. In the absence of contemporary evidence-based data, the panel found RAND-modified Delphi methodology effective in providing a formal framework for developing consensus recommendations for the timing and sequence of cellular therapies for MCL.

ASTCT, CIBMTR, and EBMT clinical practice recommendations for transplant and cellular therapies in mantle cell lymphoma

Autologous (auto-) or allogeneic (allo-) hematopoietic cell transplantation (HCT) are accepted treatment modalities for mantle cell lymphoma (MCL). Recently, chimeric antigen receptor (CAR) T-cell therapy received approval for MCL; however, its exact place and sequence in relation to HCT is unclear. The ASTCT, CIBMTR, and the EBMT, jointly convened an expert panel to formulate consensus recommendations for role, timing, and sequencing of auto-, allo-HCT, and CAR T-cell therapy for patients with newly diagnosed and relapsed/refractory (R/R) MCL. The RAND-modified Delphi method was used to generate consensus statements. Seventeen consensus statements were generated; in the first-line setting auto-HCT consolidation represents standard-of-care in eligible patients, whereas there is no clear role of allo-HCT or CAR T-cell therapy, outside of a clinical trial. In the R/R setting, the preferential option is CAR T-cell therapy especially in MCL failing or intolerant to at least one Bruton's tyrosine kinase inhibitor, while allo-HCT is recommended if CAR T-cell therapy has failed or is not feasible. In the absence of contemporary evidence-based data, the panel found RAND-modified Delphi methodology effective in providing a formal framework for developing consensus recommendations for the timing and sequence of cellular therapies for MCL.

Exploiting gene mutations and biomarkers to guide treatment recommendations in mantle cell lymphoma

INTRODUCTION

While there has been an improvement in the treatment of mantle cell lymphoma (MCL) in both median progression-free survival (PFS; >7-8 years) and overall survival (OS; >10-12 years), patients with high-risk features such as high risk MIPI (mantle cell international prognostic index), high Ki-67 (≥30%), or blastoid variants still carry poor outcome with a median OS of 3 years. Furthermore, patients with high-risk molecular features, such as TP53 mutations, show dismal outcome, with a median OS of 1.8 years, regardless of therapy used. Further studies have led to the development of six novel drugs approved for the treatment of relapse/refractory (R/R) MCL, leading to improved survival even in refractory or high-risk patients.

AREAS COVERED

This review covers clinical biological and molecular features that impact MCL outcome with current standards. Beyond the recognition of separate subentities, we review how high-risk molecular features have paved the way towards a new paradigm away from chemoimmunotherapy.

EXPERT OPINION

Progress in novel therapies and in routine diagnostics, particularly next-generation sequencing (NGS), support the development of new treatment strategies, not based on the dose intensity/age dichotomy, which may prevent the need for chemotherapy and improve outcome across MCL including in high-risk subsets.

Intensive induction regimens after deferring initial therapy for mantle cell lymphoma are not associated with improved survival

INTRODUCTION

While most patients with mantle cell lymphoma (MCL) receive therapy shortly after diagnosis, a subset of patients with indolent-behaving disease can safely defer treatment. In this subgroup, we evaluated the importance of treatment intensity in patients with MCL who defer initial therapy.

METHODS

Out of 1134 patients with MCL from 12 academic centers, we analyzed 219 patients who initiated therapy at least 90 days after diagnosis. Patients who received induction with high-dose cytarabine and/or autologous stem cell transplantation (ASCT) in first remission were considered to have received intensive therapy (n = 88) while all other approaches were non-intensive (n = 131).

RESULTS

There was no difference in progression-free (PFS; P = .224) or overall survival (OS; P = .167) in deferred patients who received non-intensive vs. intensive therapy. Additionally, univariate and multivariate Cox proportional hazards models were performed for PFS and OS. Treatment at an academic center (HR 0.43, P = .015) was associated with improved OS in both univariate and multivariate models, while intensity of treatment was not associated with improved OS in either model.

CONCLUSIONS

These results indicate that intensified initial treatment is not associated with improved survival after deferring initial therapy, although prospective studies are needed to determine which of these patients with MCL may benefit from intensive therapy.

Mantle cell lymphoma - advances in molecular biology, prognostication and treatment approaches

Mantle cell lymphoma (MCL) is clinically characterised by its heterogenous behaviour with courses ranging from indolent cases that do not require therapy for years to highly aggressive MCL with a very limited prognosis. A better understanding of the complex biology of MCL has already led to the approval of several innovative agents, expanding the landscape of MCL therapies and improving therapeutic options especially for refractory/relapsed (R/R) disease. Nevertheless, to further optimise MCL treatment, early identification of individual risk profile and risk-adapted, patient-tailored choice of therapeutic strategy needs to be prospectively incorporated into clinical patient management. The present review highlights recent advances in deciphering the molecular background of MCL, the definition of prognostically relevant factors and the identification of potential druggable targets and summarises current treatment recommendations for primary and R/R MCL including novel targeted therapies.

Relapsed Mantle Cell Lymphoma: Current Management, Recent Progress, and Future Directions

The increasing number of approved therapies for relapsed mantle cell lymphoma (MCL) provides patients effective treatment options, with increasing complexity in prioritization and sequencing of these therapies. Chemo-immunotherapy remains widely used as frontline MCL treatment with multiple targeted therapies available for relapsed disease. The Bruton's tyrosine kinase inhibitors (BTKi) ibrutinib, acalabrutinib, and zanubrutinib achieve objective responses in the majority of patients as single agent therapy for relapsed MCL, but differ with regard to toxicity profile and dosing schedule. Lenalidomide and bortezomib are likewise approved for relapsed MCL and are active as monotherapy or in combination with other agents. Venetoclax has been used off-label for the treatment of relapsed and refractory MCL, however data are lacking regarding the efficacy of this approach particularly following BTKi treatment. Anti-CD19 chimeric antigen receptor T-cell (CAR-T) therapies have emerged as highly effective therapy for relapsed MCL, with the CAR-T treatment brexucabtagene autoleucel now approved for relapsed MCL. In this review the authors summarize evidence to date for currently approved MCL treatments for relapsed disease including sequencing of therapies, and discuss future directions including combination treatment strategies and new therapies under investigation.

18F-FDG PET/CT Cannot Substitute Endoscopy in the Staging of Gastrointestinal Involvement in Mantle Cell Lymphoma. A Retrospective Multi-Center Cohort Analysis

The detection of gastrointestinal (GI) involvement in Mantle Cell Lymphoma is often underestimated and may have an impact on outcome and clinical management. We aimed to evaluate whether baseline 18F-FDG PET/CT presents comparable results to endoscopic biopsy in the diagnosis of GI localizations. In our retrospective cohort of 79 patients, sensitivity and specificity of 18F-FDG PET/CT were low for the stomach, with a fair concordance (k = 0.32), while higher concordance with pathologic results (k = 0.65) was detected in the colorectal tract. Thus, gastric biopsy remains helpful in the staging of MCL despite 18F-FDG PET/CT, while colonoscopy could be omitted in asymptomatic patients. The validation of our data in prospective cohorts is desirable

Development and validation of a prognostic nomogram for gastric marginal zone lymphoma: a Surveillance, Epidemiology and End Results-based population study

Aim: This initial study was conducted with the aim of constructing an accurate nomogram for gastric marginal zone lymphoma patients. Methods: Data from 4414 patients diagnosed with gastric mucosa-associated lymphoid tissue lymphoma from 2004 to 2015 were retrieved from the Surveillance, Epidemiology and End Results database. Multivariate analyses were conducted for the construction of the nomogram. Results: Age, sex, race, marital status, Ann Arbor stage and radiotherapy were significantly associated with overall survival, while age, marital status, Ann Arbor stage, surgery, chemotherapy and radiotherapy were independent prognostic predictors of cause-specific survival. Stratified analysis indicated that radiotherapy alone resulted in better overall survival and cause-specific survival than chemotherapy alone. However, the present study also has several limitations; for example, patients' Helicobacter pylori infection status and the chemotherapy regimen used were unknown. Conclusion: This study constructed and validated an accurate prognostic nomogram for gastric mucosa-associated lymphoid tissue lymphoma patients.

Clinical laboratory validation of the MCL35 assay for molecular risk stratification of mantle cell lymphoma

Mantle cell lymphoma (MCL) is a clinically heterogeneous B cell malignancy for which a variety of prognostic factors have been proposed. Previously, a digital gene expression profiling "proliferation signature" capable of risk stratifying MCL was identified and subsequently developed into a multi-analyte prognostic assay, known as the "MCL35" assay. In this study, we sought to explore the performance characteristics of the MCL35 assay in a clinical laboratory and compare results with the Ki67 proliferation marker. The results describe the clinical validation of the MCL35 assay for molecular risk stratification of MCL including accuracy, sensitivity, specificity, use in acid-decalcified bone marrow core biopsies, fixatives, lower limit of RNA input, quality metrics, and other laboratory parameters. The resulting data indicate that this is a robust technique with outstanding reproducibility. Overall, the data support the concept of molecular signatures, as assessed with digital gene expression profiling, for improved standardization and reproducibility for proliferation assessment in MCL.

The impact of SAMHD1 expression and mutation status in mantle cell lymphoma: An analysis of the MCL Younger and Elderly trial

The sterile alpha motif and histidine-aspartic domain-containing protein 1 (SAMHD1) has been demonstrated to predict the response to high-dose cytarabine consolidation treatment in acute myeloid leukemia patients. Here, we evaluated SAMHD1 as potential biomarker for the response to high-dose cytarabine in mantle cell lymphoma (MCL) patients. We quantified SAMHD1 protein expression and determined the mutation status in patients of the MCL Younger and Elderly trials (n = 189), who had received high-dose cytarabine- or fludarabine-based polychemotherapy. Additionally, we quantified SAMHD1 expression in B cell lymphoma cell lines and exposed them to cytarabine, fludarabine, and clinically relevant combinations. Across both trials investigated, SAMHD1 mutations had a frequency of 7.1% (n = 13) and did not significantly affect the failure-free survival (FFS, P = .47). In patients treated with high-dose cytarabine- or fludarabine-containing regimes, SAMHD1 expression was not significantly associated with FFS or complete remission rate. SAMHD1 expression in B cell lymphoma cell lines, however, inversely correlated with their in vitro response to cytarabine as single agent (R = .65, P = .0065). This correlation could be reversed by combining cytarabine with other chemotherapeutics, such as oxaliplatin and vincristine, similar to the treatment regime of the MCL Younger trial. We conclude that this might explain why we did not observe a significant association between SAMHD1 protein expression and the outcome of MCL patients upon cytarabine-based treatment.

Key Clinical and Translational Research Questions to Address Unmet Needs in Mantle Cell Lymphoma

Survival for patients with mantle cell lymphoma has improved dramatically over the last 2 decades owing to a better understanding of disease biology and the development of more effective treatment regimens for patients with untreated and relapsed disease. With these advancements, we are now poised to ask questions that challenge old treatment strategies, use new technologies, and improve our understanding of disease heterogeneity. This article focuses on questions that we believe will drive the future of mantle cell lymphoma treatment. Although not an exhaustive list, we review current literature, ongoing studies, and provide expert opinion on future trial design.

An update on options of therapy for aggressive mantle cell lymphoma

With the emerging application of novel targeted agents in the induction, maintenance and salvage strategies, management of aggressive mantle cell lymphoma is being transformed from high-intensity chemo-immunotherapy applicable to only selected patients, to more personalized treatment incorporating novel agents that are effective and accessible for the majority of the patients. This review summarizes risk-stratified management paradigm for aggressive mantle cell lymphoma, providing context for clinical applications of novel agents and cellular therapy including stem cell transplant and CAR-T.

Aggressive morphologic variants of mantle cell lymphoma characterized with high genomic instability showing frequent chromothripsis, CDKN2A/B loss, and TP53 mutations: A multi-institutional study

Aggressive morphologic variants of mantle cell lymphoma (MCL), including blastoid and pleomorphic (B/P-MCL), are rare and associated with poor clinical outcomes. The genomic landscape of these variants remains incompletely explored. In this multi-institutional study, we describe recurrent mutations and novel genomic copy number alterations (CNAs) in B/P-MCL, using next generation sequencing and SNP-array. Chromothripsis, a recently described phenomenon of massive chromosomal rearrangements, was identified in eight of 13 (62%) B/P MCL cases, and a high degree of genomic complexity with frequent copy number gains and losses was also seen. In contrast, a comparative cohort of nine cases of conventional MCL (C-MCL) showed no chromothripsis and less complexity. Twelve of 13 (92%) B/P-MCL cases showed loss of CDKN2A/B (6 biallelic and 6 monoallelic losses); while only one C-MCL showed monoallelic CDKN2A/B loss. In B/P-MCL, TP53 was the most commonly mutated gene, with mutations present in eight cases (62%), six of which showed concurrent loss of chromosome 17p. Of the eight cases with chromothripsis, six (85%) harbored TP53 mutations. Other recurrent mutations in B/P-MCL included ATM (7, 53%), CCND1 (5, 38%), NOTCH1 (2, 18%), NOTCH2, and BIRC3 (each in 3, 23%). Here, we describe high genomic instability associated with chromothripsis and a high frequency of CDKN2A/B and TP53 alterations in the aggressive variants of MCL. The nonrandom chromothripsis events observed in B/P-MCL may be an indicator of clinically aggressive MCL. In addition, frequent CDKN2A deletion and high genomic instability may provide potential targets for alternative treatment.

CD5-negative Mantle Cell Lymphoma: Clinicopathologic Correlations and Outcome in 58 Patients

Mantle cell lymphoma (MCL) represents 4% to 9% of all non-Hodgkin lymphomas and is characterized by CD5 and cyclin D1 expression and t(11;14)(q13;q32). However, about 5% of MCL lack CD5 expression and is poorly characterized. Here, we present 58 patients with CD5 negative (CD5) MCL and compared them with a group of 212 typical CD5 positive (CD5) MCL cases. There were 39 men and 19 women with a median age of 66 years (range, 36 to 88). Compared with CD5 positive (CD5) MCL patients, patients with CD5 MCL showed a lower male-to-female ratio (P=0.006) and a higher frequency of "bone marrow non-nodal" presentation (P=0.01). All other clinicopathologic features, including the frequency of SOX11 expression, were similar between the 2 groups. Treated with similar regimens, patients with CD5 MCL showed a significantly longer progression-free survival (PFS) (P=0.01) and a tendency for longer overall survival (OS; P=0.078) than CD5 positive (CD5) MCL patients. Univariate analysis showed of the well-known poor prognostic factors, only Mantle Cell Lymphoma International Prognostic Index was an inferior prognostic factor and blastoid/pleomorphic morphology and high Ki67 were not associated with prognosis in CD5 MCL patients. Multivariate Cox regression analysis showed CD5 expression was an independent prognostic factor for PFS (P=0.031) but not OS in MCL patients. In conclusion, the results suggest that patients with CD5 MCL have a more favorable prognosis than CD5 MCL patients, although the clinicopathologic features of both groups are largely similar. CD5 MCL may represent a distinct variant of MCL and needs to be included in the differential diagnosis of CD5 small B-cell lymphomas.

Treatment of Older Patients With Mantle Cell Lymphoma (MCL): Long-Term Follow-Up of the Randomized European MCL Elderly Trial

PURPOSE

In an update of the randomized, open-label, phase III European Mantle Cell Lymphoma (MCL) Elderly trial (ClinicalTrials.gov identifier: NCT00209209), published in 2012, we aimed to confirm results on long-term outcome focusing on efficacy and safety of long-term use of rituximab maintenance.

PATIENTS AND METHODS

Five hundred sixty patients with newly diagnosed MCL underwent a first random assignment between rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) and rituximab, fludarabine, and cyclophosphamide (R-FC) induction, followed by a second random assignment in 316 responders between rituximab and interferon alfa maintenance, to be continued until progression. We compared progression-free survival from the second randomization and overall survival (OS) from the first or second randomizations.

RESULTS

After a median follow-up time of 7.6 years, the previously described difference in OS between the induction arms persisted (median, 6.4 years after R-CHOP [n = 280] v 3.9 years after R-FC [n = 280]; P = .0054). Patients responding to R-CHOP had median progression-free survival and OS times of 5.4 and 9.8 years, respectively, when randomly assigned to rituximab (n = 87), compared with 1.9 years (P < .001) and 7.1 years (P = .0026), respectively, when randomly assigned to interferon alfa (n = 97). In 58% and 32% of patients treated with R-CHOP, rituximab maintenance was still ongoing 2 and 5 years from start of maintenance, respectively. After R-FC, rituximab maintenance was associated with an unexpectedly high cumulative incidence of death in remission (22% at 5 years). Toxicity of rituximab maintenance was low after R-CHOP (grade 3-4 leukopenia or infection < 5%) but more prominent in patients on rituximab maintenance after R-FC, in whom grade 3-4 leukopenia (up to 40%) and infections were frequent (up to 15%).

CONCLUSION

The excellent results of R-CHOP followed by rituximab maintenance until progression for older patients with MCL persisted in a mature follow-up. Prolongation of rituximab maintenance beyond 2 years is effective and safe.

KMT2D mutations and TP53 disruptions are poor prognostic biomarkers in mantle cell lymphoma receiving high-dose therapy: a FIL study

In recent years, the outcome of mantle cell lymphoma (MCL) has improved, especially in younger patients, receiving cytarabine-containing chemoimmunotherapy and autologous stem cell transplantation. Nevertheless, a proportion of MCL patients still experience early failure. To identify biomarkers anticipating failure of intensive chemotherapy in MCL, we performed target resequencing and DNA profiling of purified tumor samples collected from patients enrolled in the prospective FIL-MCL0208 phase 3 trial (high-dose chemoimmunotherapy followed by autologous transplantation and randomized lenalidomide maintenance). Mutations of KMT2D and disruption of TP53 by deletion or mutation associated with an increased risk of progression and death, both in univariate and multivariate analysis. By adding KMT2D mutations and TP53 disruption to the MIPI-c backbone, we derived a new prognostic index, the “MIPI-genetic” (“MIPI- g”). The “MIPI-g” improved the model discrimination ability compared to the MIPI-c alone, defining three risk groups: i) low-risk patients (4-year progression free survival and overall survival of 72.0% and 94.5%); ii) inter-mediate-risk patients (4-year progression free survival and overall survival of 42.2% and 65.8%) and iii) high-risk patients (4-year progression free survival and overall survival of 11.5% and 44.9%). Our results: i) confirm that TP53 disruption identifies a high-risk population characterized by poor sensitivity to conventional or intensified chemotherapy; ii) provide the pivotal evidence that patients harboring KMT2D mutations share the same poor outcome as patients harboring TP53 disruption; and iii) allow to develop a tool for the identification of high-risk MCL patients for whom novel therapeutic strategies need to be investigated. (Trial registered at clinicaltrials.gov identifier: NCT02354313).

Advances in Molecular Biology and Targeted Therapy of Mantle Cell Lymphoma

Mantle cell lymphoma (MCL) is a heterogeneous malignancy with a broad spectrum of clinical behavior from indolent to highly aggressive cases. Despite the fact that MCL remains in most cases incurable by currently applied immunochemotherapy, our increasing knowledge on the biology of MCL in the last two decades has led to the design, testing, and approval of several innovative agents that dramatically changed the treatment landscape for MCL patients. Most importantly, the implementation of new drugs and novel treatment algorithms into clinical practice has successfully translated into improved outcomes of MCL patients not only in the clinical trials, but also in real life. This review focuses on recent advances in our understanding of the pathogenesis of MCL, and provides a brief survey of currently used treatment options with special focus on mode of action of selected innovative anti-lymphoma molecules. Finally, it outlines future perspectives of patient management with progressive shift from generally applied immunotherapy toward risk-stratified, patient-tailored protocols that would implement innovative agents and/or procedures with the ultimate goal to eradicate the lymphoma and cure the patient.

Clinical management of mantle cell lymphoma in the elderly

Introduction: Mantle cell lymphoma (MCL) is a disease with an indolent histology, but mostly aggressive clinical course. While treatment can yield more promising results in younger patients, the disease is most diagnosed at a median age of approximately 70 years, and treatment in this group still presents a major challenge for oncohematologists. Unfortunately, due to comorbidities and poorer general status, the implementation of intensive treatment approaches with the cytarabine-based regimens and autologous stem cell transplantation is generally not possible, and the disease remains incurable, especially in elderly patients. Areas covered: In this paper, the authors discuss the therapeutic options available for older patients with MCL in the first line and relapsed/refractory settings, indicating new therapeutic options, which may achieve longer remissions and overall survival. Expert opinion: Although great progress has been made in the treatment of MCL in recent years, there remains a need for new treatment lines which can allow improved patient outcomes. Novel agents targeting altered the signal transduction pathways in MCL cells may offer more promise than traditional chemotherapy or immunochemotherapy and are currently being tested in clinical trials.

Optimal management of mantle cell lymphoma in the primary setting

Introduction: The management of mantle cell lymphoma (MCL) has significantly improved since the use of intensified induction and autologous stem cell transplant consolidation. Evolving developments in minimal residual disease detection and novel agent therapy are now challenging this frontline treatment paradigm. Areas covered: This review discusses both the established role of induction and transplant consolidation in MCL, followed by evolving concepts in the use of novel agents in the frontline setting, and the use of minimal residual disease as a driver of MCL management. Expert opinion: In an era of novel agents and improved biologic understanding of MCL, our goal for frontline management should evolve toward personalized therapy for individual patients to maximize efficacy and survival whilst minimizing treatment-related toxicities.

CD23 expression in mantle cell lymphoma is associated with CD200 expression, leukemic non-nodal form, and a better prognosis

Mantle cell lymphoma (MCL) is usually CD23 negative, a feature helpful in distinguishing MCL from chronic lymphocytic leukemia/small lymphocytic lymphoma. However, a subset of MCL cases can be CD23+. Limited data are available regarding the clinicopathological features and prognosis of patients with CD23+ MCL. In this study, we reviewed 798 cases of MCL and identified 103 (13%) that were CD23+ by flow cytometry, all of which were positive for cyclin D1 and/or associated with CCND1/IGH. In all cases of CD23+ MCL, CD23 expression was dim partial or dim, unlike moderate to bright CD23 expression observed in chronic lymphocytic leukemia/small lymphocytic lymphoma. The clinicopathological features and outcome of patients with CD23+ MCL were compared with 240 patients with typical MCL negative for CD23. Patients with CD23+ MCL more often had an elevated leukocyte count (33% versus 18%, P = .009), bone marrow involvement (89% versus 78%, P = .02), stage 4 disease (87% versus 77%, P = .03), and a leukemic presentation (42% versus 11%, P = .0001). CD23+ MCL was also more often positive for CD200 (17% versus. 4.6%, P = .0005) and less commonly positive for SOX11 (55% versus. 74%, P = .027). All other clinicopathological features were similar. With similar treatment regimens and observation times, patients with CD23+ MCL had a significant better overall survival (P = .02) and progression-free survival (P = .029). In conclusion, CD23 expression was observed in 13% of MCL cases and is associated with a better prognosis in patients with MCL. CD23 is associated with leukocytosis, a leukemic presentation, bone marrow involvement, CD200 expression, and a lower frequency of SOX11 positivity.