Rituximab maintenance therapy for mantle cell lymphoma: A systematic review and meta-analysis

Real-World Evidence of Relapsed/Refractory Mantle Cell Lymphoma Patients and Treatments: A Systematic Review

Introduction

Mantle cell lymphoma (MCL) is an incurable disease with an aggressive clinical course, and most patients eventually relapse after chemotherapy. Targeted therapies developed for relapsed/refractory MCL have been approved based on clinical trial data. However, real-world setting data are scarce and scattered.

Areas Covered

This systematic review aimed to collect, synthesize, and describe the characteristics and treatment outcomes of patients with relapsed/refractory MCL after receiving a second or subsequent line of therapy in the real-world setting.

Expert Opinion

R/R MCL is clinically and biologically heterogeneous and still represents a therapeutic challenge, with high-risk and early relapsed patients remaining an unmet medical need. This systematic review is limited by the quality of the available data and the difficulty of comparing outcomes in R/R MCL due to the heterogeneity of the disease, but the results suggest that covalent BTKis should be positioned as second-line therapy, followed by CAR T-cells in BTK-i-relapsed patients. Chemo-free and combination therapies with established chemoimmunotherapy backbones in the relapsed and front-line settings have been recently developed, and front-line options are being improved to move targeted and cellular therapies to earlier lines, including front-line therapy, in elderly and younger fit patients. In the upcoming years, many new targeted agents will play an important role and will be incorporated to the routine practice as their sequence, and outcomes in unselected patients are determined.

Efficacy of front-line immunochemotherapy for transplant-ineligible mantle cell lymphoma: A network meta-analysis of randomized controlled trials

BACKGROUND

There is no standard first-line immunochemotherapy regimen for transplant-ineligible patients with mantle cell lymphoma (MCL) currently, and the efficacy of various treatment remains unclear.

METHODS

We conducted a Bayesian network meta-analysis (NMA) of all eligible randomized controlled trials. Pairwise comparisons and ranking of different first-line treatment options were performed.

RESULTS

Nine studies were included in the NMA, involving a total of 2897 MCL patients. The BR-Ibrutinib+R regimen showed the best progression-free survival (PFS), with a surface under the cumulative ranking curve (SUCRA) of 0.89 and probability of being the best treatment (PbBT) of 69%. The VR-CAP regimen was the most potential intervention to improve overall survival (OS), with a SUCRA of 0.89 and PbBT of 63%. Compared with the R-CHOP regimen, the BR regimen achieved a better PFS (hazard ratio [HR] 0.45 [95% credible interval 0.2-0.96]). The BR-Ibrutinib+R regimen (HR 0.14 [0.02-0.99]), BR+R regimen (HR 0.19 [0.034-0.99]), and BR regimen (HR 0.3 [0.08-1.03]) were superior to CHOP regimen with better PFS. The R-FC regimen (HR 2.27 [1.01-5.21]) or FC regimen (HR 3.17 [1.15-8.71]) was inferior to the VR-CAP regimen with a worse OS.

CONCLUSIONS

Our study presents the most promising first-line treatment strategy for transplant-ineligible MCL patients in terms of PFS and OS, which provides innovative treatment strategy for MCL treatment.

First-Line Autologous Stem Cell Transplantation for Mantle Cell Lymphoma: A Systematic Analysis and Treatment Recommendation

Background

In the era of immunotherapy, autologous stem cell transplantation (ASCT) in first-line therapy in patients with mantle cell lymphoma (MCL) has been a controversial topic. This report aimed to explore the association between ASCT and MCL survival through a systematic review with meta-analysis.

Methods

We performed a systematic search of original articles published from inception to September 2021 using PubMed, MEDLINE, Embase, and Cochrane Library databases.

Results

We included studies that compared ASCT with non-ASCT consolidation in newly diagnosed transplant-eligible MCL. The endpoints were progression-free survival (PFS) and overall survival (OS). There were seven eligible studies (one randomized clinical trial, one prospective cohort study, and five observational studies) published between 2012 and 2021, in which the total number of participants was 3,271. In the non-intensive induction subgroup, patients with ASCT experienced a significant PFS but no OS benefit compared with those without ASCT. In the intensive induction subgroup, the PFS benefit from ASCT still existed but largely attenuated; no OS benefit was observed though only one study was suitable for evaluation. When compared to the rituximab maintenance arm, ASCT had a worse PFS and OS.

Conclusions

In the rituximab plus HiDAC era, the benefit of ASCT as a component of first-line treatment has been weakened. First-line maintenance strategy instead of ASCT seems worth exploring .

Stem cell transplant for mantle cell lymphoma in Taiwan

Mantle cell lymphoma (MCL) is a B-cell lymphoma featuring an aggressive course and a progressive relapsing pattern. International guidelines recommend early consolidative autologous stem cell transplant (auto-SCT) for eligible patients while reserving allogeneic SCT (allo-SCT) as therapy for refractory cases. Since data describing the implementation of transplants in the Asian population with MCL are limited, we aimed to analyze post-SCT outcomes of 99 MCL patients from the Taiwan Bone Marrow Transplant Registry database. The median age was 56 years, and 11% of the patients had blastoid variant MCL. Ninety-four patients received auto-SCT, while 13 patients received allo-SCT, eight of which received allo-SCT after failing auto-SCT. Before auto-SCT, 52% of the patients were in their first complete remission (CR1). Overall, 37 patients (39%) relapsed after auto-SCT. The median post-auto-SCT progression-free survival and overall survival (OS) were 43.6 months and not reached, respectively. Blastoid variant MCL, transplant not received in CR1, and disease progression within 12 months post-auto-SCT independently predicted inferior OS in multivariable analysis. The median post-allo-SCT OS was 74 months. Two patients (15%) died of MCL recurrence post-allo-SCT. Three patients with refractory diseases were salvaged with ibrutinib or venetoclax to allo-SCT. Treatment strategies incorporating novel agents warrant further optimization.

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.

Impact of Mantle Cell Lymphoma Contamination of Autologous Stem Cell Grafts on Outcome after High-Dose Chemotherapy

Simple Summary

High-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (Auto-HSCT) is a standard frontline treatment for fit mantle cell lymphoma (MCL) patients. As there is a need for predictive factors to identify patients unlikely to benefit from this therapy, we investigated the prognostic impact of lymphoma cell contamination of autologous stem cell grafts. Analyzing a cohort of 36 MCL patients, we show that lymphoma cell contamination of stem cell grafts is associated with poor outcomes after Auto-HSCT. Its analysis might thus improve risk assessment and enable risk-stratified treatment strategies for MCL patients.

Abstract

Novel predictive factors are needed to identify mantle cell lymphoma (MCL) patients at increased risk for relapse after high-dose chemotherapy and autologous hematopoietic stem cell transplantation (HDCT/Auto-HSCT). Although bone marrow and peripheral blood involvement is commonly observed in MCL and lymphoma cell contamination of autologous stem cell grafts might facilitate relapse after Auto-HSCT, prevalence and prognostic significance of residual MCL cells in autologous grafts are unknown. We therefore performed a multiparameter flow cytometry (MFC)-based measurable residual disease (MRD) assessment in autologous stem cell grafts and analyzed its association with clinical outcome in an unselected retrospective cohort of 36 MCL patients. MRD was detectable in four (11%) autologous grafts, with MRD levels ranging from 0.002% to 0.2%. Positive graft-MRD was associated with a significantly shorter progression-free and overall survival when compared to graft-MRD negative patients (median 9 vs. 56 months and 25 vs. 132 months, respectively) and predicted early relapse after Auto-HSCT (median time to relapse 9 vs. 44 months). As a predictor of outcome after HDCT/Auto-HSCT, MFC-based assessment of graft-MRD might improve risk stratification and support clinical decision making for risk-oriented treatment strategies in MCL.

Phase 1 studies comparing safety, tolerability, pharmacokinetics and pharmacodynamics of HLX01 (a rituximab biosimilar) to reference rituximab in Chinese patients with CD20-positive B-cell lymphoma

Objective

This study aimed to compare the pharmacokinetic, pharmacodynamic and safety profiles of HLX01 (a rituximab biosimilar) and reference rituximab sourced from China (MabThera^®; rituximab-CN).

Methods

Here we report the results of two phase 1 studies. In the phase 1a, open-label, dose-escalation study (NCT03218072, CTR20140400), eligible patients received 250, 375 and 500 mg/m² HLX01 sequentially at 7-day intervals, after confirming no dose-limiting toxicity (DLT). In the phase 1b, double-blind study (NCT02584920, CTR20140764), eligible patients were given a single dose of 375 mg/m² HLX01 or rituximab-CN. The primary endpoints included safety and tolerability parameters for the phase 1a and the area under the plasma concentration-time curve from time zero to day 91 (AUC_{0−91 d}) for the phase 1b study. Equivalence was concluded if 90% confidence interval (90% CI) for the geometric least squares mean ratio (GLSMR) fell in the pre-specified equivalence criteria (80%−125%).

Results

Between June 20, 2014 and January 5, 2015, 12 patients were enrolled in the phase 1a study. The pharmacokinetics of HLX01 showed dose proportionality and accumulation to steady state. HLX01 was well tolerated, with no serious adverse events (AEs), discontinuations or DLTs. Between November 8, 2014 and August 13, 2015, 87 eligible patients were enrolled in the phase 1b study, including 43 who received HLX01 and 44 who were treated with rituximab-CN. The equivalence endpoint was met with GLSMR for AUC_{0−91 d} being 89.6% (90% CI: 80.4%−99.8%). AEs, anti-drug antibodies, and CD19+ and CD20+ B lymphocyte counts were similar between the HLX01 and rituximab-CN treatment groups.

Conclusions

Treatment with HLX01 was safe and well tolerated in Chinese patients with B-cell lymphoma. HLX01 and rituximab-CN have similar pharmacokinetic, pharmacodynamic and safety profiles.

First-line therapy, autologous stem-cell transplantation, and post-transplantation maintenance in the management of newly diagnosed mantle cell lymphoma

Background

In Ontario, no clearly defined standard of care for the management of mantle cell lymphoma (mcl) has been developed, and substantial variability from centre to centre is evident. This guidance document was prompted by the need to harmonize practice in Ontario with respect to first-line, conditioning, and post-transplantation maintenance therapy for patients newly diagnosed with transplantation-eligible mcl.

Methods

The medline and embase databases were systematically searched from January 2013 to January 2020 for evidence, and the best available evidence was used to draft recommendations relevant to first-line therapy, autologous stem-cell transplantation, and post-transplantation maintenance in the management of transplantation-eligible newly diagnosed mcl. Final approval of this guidance document was obtained from the Stem Cell Transplant Advisory Committee.

Recommendations

These recommendations apply to all cases of transplantation-eligible newly diagnosed mcl:■ Alternating cycles of r-chop (rituximab plus cyclophosphamide-doxorubicin-vincristine-prednisolone) and r-dhap [rituximab plus dexamethasone-high-dose cytarabine-cisplatin] is the recommended first-line treatment for symptomatic patients newly diagnosed with mcl before autologous stem-cell transplantation (asct).■ Rituximab plus hyperfractionated cyclophosphamide-vincristine-doxorubicin-dexamethasone (r-hypercvad), alternating with methotrexate and cytarabine, is not recommended for the treatment of patients with newly diagnosed mcl.■ beam (carmustine-etoposide-cytarabine-melphalan), beac (carmustine-etoposide-cytarabine-cyclophosphamide), and total-body irradiation-based regimens are reasonable conditioning options for patients with mcl who have responded to first-line therapy and who are undergoing asct.■ Maintenance therapy with rituximab is recommended for patients with newly diagnosed mcl who have undergone asct.

Rituximab-induced acute thrombocytopenia in patients with splenomegaly B Cell lymphoma: an underdiagnosed but severe complication

Rituximab is popularly used in the treatment of B-cell lymphomas that bear CD20 antigen. Most of the adverse events (AEs) induced by rituximab are infusion-related symptoms. However, rituximab-induced acute thrombocytopenia (RIAT), which often develops within the 1-3 days after rituximab administration, is relatively unusual, severe, and usually self-recovering. Until now, most of the reports about RIAT were described as case reports and RIAT often occurred in patients with mantle cell lymphoma (MCL). Here, we report two patients who developed severe RIAT, one patient had a refractory and relapsed follicular lymphoma (FL), and the other patient was newly diagnosed with splenic marginal zone lymphoma (SMZL). RIAT is a rare, under-diagnosed but serious adverse event that should arouse attention to clinicians, and routine blood count monitoring should be considered after the administration of rituximab, especially for high-risk lymphoma patients or patient with splenomegaly.