A retrospective study evaluating the efficacy and safety of bendamustine in the treatment of mantle cell lymphoma

Measurable Residual Disease Testing Following Nonintensive Chemoimmunotherapy is Predictive of Need for Maintenance Therapy in Previously Untreated Mantle Cell Lymphoma: A Wisconsin Oncology Network Study

INTRODUCTION

Obinutuzumab is hypothesized to improve progression-free survival (PFS) combined with bendamustine induction in mantle cell lymphoma (MCL). Measurable-residual disease (MRD) testing may predict benefit from maintenance therapy.

METHODS

Adults (≥ 18 years) with untreated MCL ineligible for intensive therapies received 4 to 6 cycles of bendamustine + obinutuzumab (BO) followed by consolidation obinutuzumab (CO). Restaging after CO included MRD assessment by next-generation sequencing of bone marrow aspirate (BMA) and peripheral blood (PB). Maintenance obinutuzumab (MO) was omitted for patients with imaging complete response (CR) and MRD-negativity in PB/BMA. All other patients received 8 cycles MO. Primary endpoint is PFS; secondary endpoints are response rates, overall survival, and estimation of MRD status.

RESULTS

Twenty-one patients enrolled, with median age 70 years and stage IV disease in 95%. Twenty patients completed BO; 10 patients received MO per protocol. Six patients did not complete MO due to progression (n = 4), infection (n = 1) and carcinoma (n = 1). Overall response is 95% (75% CR, 20% partial response). Concordance rate between post-consolidation MRD testing in PB and BMA was 70%. After a median follow-up of 43.9 months, median PFS is 46.5 months. The observed difference between 2-year PFS in groups receiving MO versus observation was not statistically significant (HR 0.45, 95% CI, 0.10-1.91). Most common grade 3/4 toxicities were neutropenia, leukopenia, and infections.

CONCLUSIONS

BO is a tolerable induction regimen with higher rates of CR compared with historical rates with bendamustine + rituximab. Omission of MO did not worsen outcomes in patients achieving MRD-negative status after nonintensive induction/consolidation therapy.

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.

Post-marketing risk analysis of bendamustine: a real-world approach based on the FAERS database

Objective: Bendamustine was approved for treating chronic lymphocytic leukemia and indolent B-cell non-Hodgkin lymphoma. Despite its therapeutic benefits, the long-term safety of bendamustine in a large population remains inadequately understood. This study evaluates the adverse events (AEs) associated with bendamustine, using a real-world pharmacovigilance database to support its clinical application. Methods: We conducted a post-marketing risk analysis to assess the association between bendamustine and its AEs. Data were extracted from the US FDA's Adverse Event Reporting System (FAERS), covering the period from January 2017 to September 2023. The characteristics of bendamustine-associated AEs and the onset time were further analyzed. Statistical analysis was performed using MYSQL 8.0, Navicat Premium 15, Microsoft EXCEL 2016, and Minitab 21.0. Results: 9,461,874 reports were collected from the FAERS database, 9,131 identified bendamustine as the "primary suspected" drug. We identified 331 significant disproportionality preferred terms (PTs). Common AEs included pyrexia, neutropenia, infusion site reaction, progressive multifocal leukoencephalopathy (PML), injection site vasculitis, and pneumonia-all documented on bendamustine's label. Notably, 16 unexpected and significant AEs were discovered, including hypogammaglobulinemia, which is concerning due to its potential to increase infection susceptibility following bendamustine treatment. Other significant findings were anaphylactic reactions, PML, and cutaneous malignancies, suggesting updates to the drug's label may be necessary. Physicians should monitor for neurological and skin changes in patients and discontinue treatment if PML is suspected. Moreover, the median onset time for bendamustine-associated AEs was 13 days, with an interquartile range [IQR] of 0-59 days, predominantly occurring on the first day post-initiation. The β of bendamustine-related AEs suggested risk reduction over time. Conclusion: Our study uncovered some potential pharmacovigilance signals for bendamustine, providing important insights for its safe and effective clinical use.

Treatment patterns, adverse events, healthcare resource use and costs among commercially insured patients with mantle cell lymphoma in the United States

INTRODUCTION

There are limited data on treatment patterns, adverse events (AEs), and economic burden in younger, commercially insured patients treated for mantle cell lymphoma (MCL).

METHODS

Adults with ≥1 treatment for MCL between 1 November 2013-31 December 2017 were identified from IQVIA Real-World Data Adjudicated Claims-US; index date was first treatment. Patients carried ≥1 MCL diagnosis, were newly treated, and were enrolled continuously for ≥12 months prior to and ≥30 days following index. Patients receiving the four most common MCL regimens were included. Measures included frequency of incident AEs, resource use, and costs overall and by number of AEs. Adjusted logistic regression and generalized linear modeling evaluated risk of hospitalization and all-cause costs per patient per month (PPPM).

RESULTS

Two thousand five hundred and nine treated patients had a drug-specific code and were classified to a specific treatment regimen. Of those patients, 1785 patients received at least one of the four most commonly used MCL regimens (R-CHOP, rituximab monotherapy, B-R, and ibrutinib) at some point over follow-up (median 23 months). R-CHOP was the most common regimen observed in the first line (26%), followed by rituximab monotherapy (19%), B-R (15%), and ibrutinib (5%). The median age was 57 years; median Charlson Comorbidity Index was 0. Among patients receiving the four most common regimens, 63% of patients experienced ≥1 incident AE (R-CHOP 77%, B-R 58%, and ibrutinib 52%). An increasing number of incident AEs was associated with increased hospitalization risk (odds ratio = 2.4; 95% Confidence Interval [CI] 2.1-2.7) and increased mean costs PPPM (cost ratio = 1.1; 95% CI 1.1-1.2).

DISCUSSION

This is the largest study describing treatment patterns and clinical and economic impact of MCL treatment. The most common regimens were R-CHOP, rituximab monotherapy, B-R, and ibrutinib. The majority of treated patients experienced at least one incident AE, with hospitalization risk and all-cause costs increasing as the number of AEs increased.

Phase II study of bendamustine combined with rituximab in relapsed/refractory mantle cell lymphoma: efficacy, tolerability, and safety findings

In most cases of relapsed/refractory mantle cell lymphoma (MCL), patients respond to salvage therapy, though typically responses are partial and/or transient followed by disease progression, even with newer agents (e.g., ibrutinib). In this multicenter, open-label, single-arm, phase II study, patients with relapsed/refractory non-blastoid MCL received bendamustine 90 mg/m(2) (days 1 and 2) and rituximab 375 mg/m(2) (day 1) for 6 planned 28-day cycles. Functional imaging with 18-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) was conducted at baseline and after cycle 6. Forty-five patients were enrolled (median age, 70 years; 82 % stage IV disease; median number of prior chemotherapies, 2 [range, 1-4]), showing an overall response rate (ORR; primary efficacy measure) of 82 % (complete response [CR], 40 %; partial response, 42 %). In the 32 patients with complete 18F-FDG PET/CT data, 75 % achieved a complete metabolic response. Median duration of response was 1.6 years, 1-year progression-free survival was 67 %, and 3-year overall survival was 55 %. Main non-hematologic adverse events were nausea (69 %), fatigue (56 %), decreased appetite (42 %), constipation (38 %), diarrhea (36 %), vomiting (36 %), and decreased weight (31 %). Grade 3/4 neutropenia and lymphopenia occurred in 44 and 89 % of patients, respectively. ORR and CR rate compared favorably with single-agent ibrutinib (ORR, 67 %; CR, 23 %); bendamustine-rituximab is an effective therapy with manageable toxicity in relapsed/refractory MCL.

Pharmacokinetic and pharmacodynamic profile of bendamustine and its metabolites

Purpose

Bendamustine is a unique alkylating agent indicated for the treatment of chronic lymphocytic leukemia and rituximab-refractory, indolent B cell non-Hodgkin’s lymphoma. Despite the extensive experience with bendamustine, its pharmacokinetic profile has only recently been described. This overview summarizes the pharmacokinetics, pharmacokinetic/pharmacodynamic relationships, and drug–drug interactions of bendamustine in adult and pediatric patients with hematologic malignancies.

Methods

A literature search and data on file (including a human mass balance study, pharmacokinetic population analyses in adult and pediatric patients, and modeling analyses) were evaluated for inclusion.

Results

Bendamustine concentrations peak at end of intravenous infusion (~1 h). Subsequent elimination is triphasic, with the intermediate t_1/2 (~40 min) as the effective t_1/2 since the final phase represents <1 % of the area under the curve. Bendamustine is rapidly hydrolyzed to monohydroxy-bendamustine and dihydroxy-bendamustine, which have little or no activity. Cytochrome P450 (CYP) 1A2 oxidation yields the active metabolites γ-hydroxybendamustine and N-desmethyl-bendamustine, at low concentrations, which contribute minimally to cytotoxicity. Minor involvement of CYP1A2 in bendamustine elimination suggests a low likelihood of drug–drug interactions with CYP1A2 inhibitors. Systemic exposure to bendamustine 120 mg/m² is comparable between adult and pediatric patients; age, race, and sex have been shown to have no significant effect on systemic exposure in either population. The effect of hepatic/renal impairment on bendamustine pharmacokinetics remains to be elucidated. Higher bendamustine concentrations may be associated with increased probability of nausea or infection. No clear exposure–efficacy response relationship has been observed.

Conclusions

Altogether, the findings support dosing based on body surface area for most patient populations.

Pharmacokinetic profile and first preliminary clinical evaluation of bendamustine in Taiwanese patients with heavily pretreated indolent B-cell non-Hodgkin lymphoma and mantle cell lymphoma

Prior studies found bendamustine is efficacious in patients with indolent B-cell non-Hodgkin lymphoma (NHL). To date, no studies have reported the efficacy of bendamustine in a Chinese population. This multicentre phase II trial evaluated the pharmacokinetics (PK), safety and efficacy of bendamustine monotherapy in Chinese patients in Taiwan with pretreated indolent B-cell NHL or mantle cell lymphoma (MCL). For PK assessments, patients were randomized (n = 16; 11 with indolent B-cell NHL and five with MCL) to 90 or 120 mg/m(2) of bendamustine for the first cycle. Plasma levels of bendamustine and its two metabolites were analyzed. For efficacy and safety evaluations, bendamustine 120 mg/m(2) was given to all patients every 3 weeks starting at cycle 2 for a minimum of a total of six cycles. The median age of patients was 61.7 years, and the majority were men (75%). The median number of prior treatments was 4 (range, 1-9 regimens), and all patients were previously treated with rituximab. Bendamustine plasma concentration peaked near the end of infusion and was rapidly eliminated with a mean elimination half-life (t(1/2)) of 0.67-0.8 h. Of the evaluable patients (n = 14), the overall response rate was 78.6%, including 7.2% of patients having a complete response. Mean progression-free survival was 27.5 weeks. The most common grade 3-4 adverse events were leucopenia (56.3%), neutropenia (56.3%) and thrombocytopenia (25%). In conclusion, bendamustine was efficacious and well tolerated in Taiwanese patients with indolent NHL and MCL with a similar PK profile to that of other populations.

Bendamustine as salvage treatment for patients with relapsed or refractory mantle cell lymphoma patients: a retrospective study of the Spanish experience

Patients with mantle cell lymphoma (MCL) have an adverse outcome after relapse. Bendamustine has demonstrated a good efficacy and toxicity profile in previously reported trials. In this study, we present a retrospective analysis of the Spanish experience in relapsed/refractory MCL treated with bendamustine in combination or alone with the objective of knowing the efficacy and toxicity profile of this treatment in our current clinical practice. Fifty eight patients were registered: 67 % male with median age of 71 years, and 2 is the median number of previous lines. The most frequent bendamustine regimen was bendamustine plus rituximab (83 %). The median number of cycles was 5 (range 1-8). The overall response rate was 84 % with 53 % of complete response/unconfirmed complete response (CR/uCR). Median progression-free survival (PFS) was 16 months (95 % confidence interval (CI) 13.3-18.8), and for patients who achieved CR/uCR, it was 33 months (95 % CI 11.1-54.2). Median overall survival (OS) was 30 months (95 % CI 25.6-34.9). For PFS, only blastoid histology and not achieving CR after bendamustine had a significant negative impact on the univariate and multivariate analyses (p < 0.05). Nevertheless, for OS, only an elevated lactate dehydrogenase (LDH) had negative impact on both, univariate and multivariate analyses (p < 0.05). Only one case of treatment-related mortality in a 79-year-old patient with very bad performance status was reported. In 280 cycles, 12 (4 %) hospitalizations for febrile neutropenia were reported. In our population, bendamustine has been a good salvage treatment with a favorable toxicity profile in a non selected and heavily pretreated population of patients with MCL.