Multicenter phase II study of bendamustine for relapsed or refractory indolent B-cell non-Hodgkin lymphoma and mantle cell lymphoma

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.

Navigating between Scylla and Charybdis: A roadmap to do better than Pola-RCHP in DLBCL

In treating diffuse large B-cell lymphoma (DLBCL), oncologists have traditionally relied on the chemotherapy backbone of R-CHOP as standard of care. The two dangers that the hematologist must navigate between are the aggressive disease (Charybdis that in the absence of therapy systematically destroys all the ships) and the toxicity of the therapies (Scylla with its six monstrous heads that devours six crew members at a time), and hematologists have to navigate very carefully between both. Therefore, three different strategies were employed with the goal of improving cure rates: de-escalating regimens, escalating regimens, and replacement strategies. With a replacement strategy, a breakthrough in treatment was identified with polatuzumab vedotin (anti-CD79B antibody/drug conjugate) plus R-CHP. However, this regimen still did not achieve the elusive universal cure rate. Fortunately, advances in genomic and molecular technologies have allowed for an improved understanding of the heterogenous molecular nature of the disease to help develop and guide more targeted, precise, and individualized therapies. Additionally, new pharmaceutical technologies have led to the development of novel cellular therapies, such as chimeric antigen receptor (CAR) T-cell therapy, that could be more effective, while maintaining an acceptable safety profile. Thus, we aim to highlight the challenges of DLBCL therapy as well as the need to address therapeutic regimens eventually no longer tethered to a chemotherapy backbone. In the intersection of artificial intelligence and multi-omics (genomics, epigenomics, transcriptomics, proteomics, metabolomics), we propose the need to analyze multidimensional biologic datato launch a decisive attack against DLBCL in a targeted and individualized fashion.

Efficacy and safety of copanlisib in relapsed/refractory B-cell non-Hodgkin lymphoma: A meta-analysis of prospective clinical trials

BACKGROUND

Copanlisib is an intravenously administered pan-class I PI3K inhibitor that has been demonstrated to have appreciable effects in the treatment of patients with lymphoma. The purpose of this meta-analysis was to evaluate the efficacy and safety of copanlisib for treating patients with relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma (B-NHL).

METHODS

PubMed, Web of Science, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for relevant studies published prior to July 2022. The efficacy evaluation included complete response rate (CR), partial response rate (PR), rate of stable disease (SDR), overall response rate (ORR), disease control rate (DCR), rate of progressive disease (PDR), median progression-free survival (PFS), and median overall survival (OS). Any grade adverse events (AEs) and grade ≥3 AEs were synthesized to assess its safety.

RESULTS

Eight studies with a total of 652 patients with R/R B-NHL were identified. The pooled CR, PR, ORR, SDR, DCR, and PDR from all 8 articles were 13%, 40%, 57%, 19%, 86%, and 9%, respectively. The CR and ORR of combination therapy with rituximab were higher than those with copanlisib monotherapy for R/R B-NHL (34% vs. 6%, p<0.01; 89% vs. 42%, p<0.01). For patients with R/R indolent B-NHL, CR and ORR were lower with copanlisib monotherapy than with combination therapy with rituximab (7% vs. 34%, p<0.01; 58% vs. 92%, p<0.01). In R/R B-NHL patients receiving copanlisib monotherapy and combination therapy with rituximab, the risk of any grade AEs was 99% and 96%, respectively, and the risk of grade ≥3 AEs was 84% and 91%, respectively. The common any grade AEs included hyperglycemia (66.75%), hypertension (48.57%), diarrhea (35.06%), nausea (34.98%) and fatigue (30.33%). The common grade ≥3 AEs included hyperglycemia (45.14%), hypertension (35.07%), and neutropenia (14.75%). The comparison of AEs between the copanlisib monotherapy and the combination therapy with rituximab showed that hyperglycemia of any grade (p<0.0001), hypertension of any grade (p=0.0368), fatigue of any grade (p<0.0001), grade ≥3 hypertension (p<0.0001) and grade ≥3 hyperglycemia (p=0.0074) were significantly different between the two groups.

CONCLUSION

Our meta-analysis demonstrated that the efficacy of both copanlisib monotherapy and combination therapy with rituximab in patients with R/R B-NHL was satisfactory, while treatment-related AEs were tolerable. Compared with copanlisib monotherapy, combination therapy with rituximab showed superior efficacy for treating R/R B-NHL, and its safety was manageable.

SYSTEMATIC REVIEW REGISTRATION

https://inplasy.com/inplasy-2022-10-0008/, identifier INPLASY2022100008.

[Bendamustine monotherapy for Chinese patient treatment with relapsed or refractory B cell non-Hodgkin lymphoma: a phase Ⅱ, prospective, multicenter, single-arm study]

Objective: To evaluate the efficacy and safety of bendamustine monotherapy in Chinese patients with relapsed/refractory (R/R) B cell non-Hodgkin lymphoma (B-NHL) . Methods: This prospective, multicenter, open label, single-arm, phase Ⅱ study investigated bendamustine's efficacy and safety in Chinese patients with R/R B-NHL. A total of 78 patients with B-NHL in 11 hospitals in China from March 2012 to December 2016 were included, and their clinical characteristics, efficacy, and survival were analyzed. Results: The median age of all patients was 58 (range, 24-76) years old, and 69 (88.4% ) patients had stage Ⅲ/Ⅳ disease. 61 (78.2% ) patients were refractory to previous treatments. Patients received a median of 4 (range, 1-10) cycles of bendamustine treatment. The overall response rate was 61.5 (95% CI 49.8-72.3) % , the median response duration was 8.3 (95% CI 5.5-14.0) months, and the complete remission (CR) rate was 5.1 (95% CI 1.4-12.6) % . In the full analysis set, median progression-free survival (PFS) and median OS were 8.7 (95% CI 6.7-13.2) months and 25.5 months (95% CI 14.2 months to not reached) , respectively, after a median follow-up of 33.6 (95% CI 17.4-38.8) months. Lymphopenia (74.4% ) , neutropenia (52.6% ) , and leukopenia (39.7% ) , thrombocytopenia (29.5% ) and anemia (15.4% ) were the most common grade 3-4 hematologic adverse events (AE) . The most frequent non-hematologic AEs included nausea (43.6% ) , vomiting (33.3% ) , and anorexia (29.5% ) . Univariate and multivariate analysis showed that <4 cycles of bendamustine treatment was a poor prognostic factor for PFS (P=0.003) , and failure to accept fludarabine containing regimen was a poor prognostic factor for OS (P=0.009) . Conclusion: Bendamustine monotherapy has good efficacy and safety in the treatment of patient with R/R B-NHL.

Bendamustine versus chlorambucil in treatment of chronic lymphocytic leukaemia in China: a randomized, open-label, parallel-controlled, phase III clinical trial

BACKGROUND

Chronic lymphoblastic leukemia (CLL) is the most common adult leukemia and mainly affects the elderly. Chemoimmunotherapy still has a role in the standard frontline therapy for specific population. However, the clinical activity of bendamustine has not been investigated in unfit Chinese patients with CLL. This study aimed to compare the efficacy and safety of bendamustine versus chlorambucil for untreated Chinese patients with Binet stage B/C CLL.

METHODS

In this multi-center, randomized, open-label, parallel-controlled, phase III trial, patients with previously untreated CLL were enrolled and randomly assigned (1:1) to receive bendamustine or chlorambucil. The primary endpoint was the objective response rate. Secondary endpoints included progression-free survival, the duration of response, and overall survival. Adverse events were recorded to evaluate safety.

RESULTS

Of 158 screened patients, 147 were enrolled and randomly allocated to receive bendamustine (n = 72) or chlorambucil (n = 75). After a median follow-up of 25.6 months (IQR 12.5-27.7), 69.0% (95% CI, 56.9-79.5) of bendamustine-treated patients achieved objective response and 37.0% (95% CI, 26.0-49.1) of chlorambucil with a difference of 32.0% (95%CI: 16.6-47.5), demonstrating the superiority of bendamustine to chlorambucil (p < 0.001). The median progression-free survival was longer for bendamustine (16.5 months; 95% CI, 11.3-24.7) versus chlorambucil (9.6 months; 95% CI, 8.7-11.8; p < 0.001). A longer median duration of response was seen in those receiving bendamustine (19.2 months; 95% CI, 11.8-29.1) than chlorambucil (10.7 months; 95% CI, 5.6-13.6; p = 0.0018). Median overall survival was not reached in either group. Overall survival at 18 months was 88% for bendamustine versus 85% for chlorambucil. Most common adverse events in both groups were neutropenia and thrombocytopenia.

CONCLUSION

In untreated Chinese patients with Binet stage B/C CLL, bendamustine induced the better objective response and resulted in longer progression-free survival than chlorambucil. Overall, these results validate the role of bendamustine as an effective and safe first-line therapy in this population.

Bendamustine-induced rash is associated with a favorable prognosis in patients with indolent B-cell lymphoma

Bendamustine is now recognized as a key drug for indolent B-cell lymphoma (iBCL), mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL). Skin toxicity associated with bendamustine is one of the characteristic adverse effects. We retrospectively examined the relationship between bendamustine-associated drug rashes and disease prognosis of iBCL and MCL at our institution. Between January 2011 and August 2019, 65 patients (39 men and 26 women, median age 68, range 41-84 years) were treated with bendamustine alone (n=11, 120 mg/m² on days 1 and 2) or a combination of rituximab and bendamustine (n=54, 90 mg/m² on days 1 and 2). Of these patients, 47 had follicular lymphoma (FL), 10 had MCL and 8 had other iBCLs. Drug rash occurred in 27 (41.5%). Eight cases (29.6%) were grade 1, 5 (18.5%) were grade 2 and 14 (51.9%) were grade 3. The onset was in the first course in 17 (63.0%), 2nd course in 5 (18.5%), 3rd course in 2 (7.4%), 4th course in 1 (3.7%) and 5th course in 2 (7.4%). No treatment was administered in 1 case (3.7%), topical steroid was applied in 10 (37.0%), antiallergic drug was administered in 2 (7.4%), topical steroid and antiallergic drug were administered in 5 (18.5%), and oral and topical steroid and antiallergic drug were administered in 9 (33.3%). The 3-year progression-free survival (PFS) and overall survival (OS) in patients with rash development were 80.0% and 85.5%, respectively, and those in patients without development were 36.4% and 54.0%, respectively (p=0.009 and 0.02, respectively). By multivariate analysis, the development of rash was associated with a better PFS and a diagnosis of iBCL was associated with a better OS. This study revealed that bendamustine-induced rash is associated with a favorable prognosis among patients with iBCL.

Phase II study of tazemetostat for relapsed or refractory B-cell non-Hodgkin lymphoma with EZH2 mutation in Japan

Tazemetostat is a selective, reversible, small-molecule inhibitor of the histone methyltransferase enzyme, enhancer of zest homolog 2 (EZH2). In this multicenter, open-label, phase II study, we assessed the efficacy and safety of tazemetostat in Japanese patients with relapsed or refractory (R/R) B-cell non-Hodgkin lymphoma harboring the EZH2 mutation. Tazemetostat (800 mg twice daily) was given orally (28-day cycle) until disease progression or unacceptable toxicity. Among the 20 eligible patients, 17 were enrolled in cohort 1 (follicular lymphoma [FL]), and three were enrolled in cohort 2 (diffuse large B-cell lymphoma). At data cut-off, the objective response rate in cohort 1 was 76.5%, including six patients (35.3%) with complete response and seven patients (41.2%) with partial response (PR). All three patients in cohort 2 achieved PR. In cohort 1, median progression-free survival (PFS) was not reached at the median follow-up of 12.9 months. The estimated PFS rate at 12 and 15 months was 94.1% and 73.2%, respectively. The most common grade 3 treatment-emergent adverse event (TEAE) was lymphopenia (n = 2). Grade 4 TEAEs included hypertriglyceridemia and pneumonia aspiration (n = 1 each), which were not related to tazemetostat. Treatment-emergent adverse events leading to study drug discontinuation were reported in four of the 20 patients, indicating that the safety profile of tazemetostat was acceptable and manageable. Tazemetostat 800 mg twice daily showed encouraging efficacy in patients with R/R EZH2 mutation-positive FL with a manageable safety profile in the overall population. Thus, tazemetostat could be a potential treatment for R/R EZH2 mutation-positive FL.

Effectiveness of bendamustine in relapsed or refractory lymphoma cases: a Turkish Oncology Group study

INTRODUCTION

We aimed to investigate the efficacy and side effects of bendamustine in relapsed/refractory lymphoma patients in Turkey.

MATERIAL AND METHODS

In this retrospective study, we included relapsed/refractory Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) patients who underwent multiple lines of chemotherapy. The primary endpoint was to determine the objective response and toxicity.

RESULTS

Ninety-nine patients with a median age of 59.8 years were included in the study. Eighty-one patients had NHL (follicular lymphoma: 10, diffuse large B-cell lymphoma: 27, mantle-cell lymphoma: 18, marginal zone lymphoma: 9, small lymphocytic lymphoma/chronic lymphocytic leukemia: 17) and 18 patients had HL. The patients had previously received a median of three lines of chemotherapy (range: 2-8) except autologous stem cell transplantation (ASCT); 19 patients (HL: 11, NHL: 8) had undergone ASCT. The objective response rate (ORR) was 74.3%, the complete response rate was 57% (= 53), and the partial response rate was 16.6% ( = 19). The overall survival (OS) rate at 1 year was 74.6%. The progression-free survival (PFS) rate at 1 year was 62.5%. The most common side effects were lymphopenia, anemia and neutropenia. Side effects which were observed as grade 3 and higher levels were lymphopenia (14.1%), neutropenia (10.1%) and fatigue (7.1%).

CONCLUSIONS

Objective response rate of bendamustine was found to be 74.3% in relapsed/refractory HL and NHL patients. It appears to be an effective option as a salvage treatment for patients who have previously received multiple lines of therapy.

Risk Factors for Skin Toxicities Associated with Bendamustine-Based Chemotherapy in Patients with Non-Hodgkin Lymphoma

Bendamustine plays an especially important role as a treatment for non-Hodgkin lymphoma (NHL). However, patients administered bendamustine alone or in combination with rituximab (BR) may experience drug-associated skin toxicities that can profoundly impact their health-related QOL through both physical discomfort and psychological distress. Moreover, worsening skin symptoms may lead to dose reduction or termination in the management of cancer chemotherapy. We retrospectively investigated patient backgrounds and pretreatment characteristics from medical records of NHL patients treated with bendamustine alone or BR therapy and identified predictive factors for skin toxicities at the start of chemotherapy. Patients were eligible for the study if they were 20 years older, diagnosed with NHL, and received bendamustine alone or BR therapy at the Department of Hematology, Kobe City Medical Center General Hospital, between April 1, 2011, and March 31, 2018. This study included 95 patients with newly diagnosed or refractory or relapsed NHL. Multivariate stepwise logistic regression analysis with backward selection revealed that baseline non-prior chemotherapy (odds ratio (OR), 15.72; 95% confidence interval (CI), 4.24-83.13, p < 0.001) was a significant factor influencing the occurrence of skin toxicity. Our results demonstrated that non-prior chemotherapy was a significant risk factor for skin toxicities in patients with NHL receiving bendamustine alone or BR therapy. No patient experience serious side effects of grade 3 or higher and that bendamustine is very useful as a first-line treatment.

Combined rituximab, bendamustine, and dexamethasone chemotherapy for relapsed or refractory indolent B-cell non-Hodgkin lymphoma and mantle cell lymphoma: a multicenter phase II study

This multicenter phase II study (UMIN000008145) aims to investigate the efficacy and safety of six cycles of combination therapy (RBD) comprising rituximab, bendamustine, and dexamethasone (DEX) for relapsed or refractory (RR) indolent B-cell non-Hodgkin lymphoma (B-NHL) and mantle cell lymphoma (MCL). Although the initial study protocol comprised 20 mg/body DEX on days 1 and 2, and 10 mg/body on days 3-5 [high-dose (HD-) DEX group], the dose of DEX was later decreased to 8 mg/body on days 1 and 2 [low-dose (LD-) DEX group] due to frequent cytomegalovirus (CMV) antigenemia and recurrent retinitis. We enrolled 33 patients, and LD-DEX and HD-DEX were administered in 15 and 18 patients, respectively. The overall response and the 3-year progression-free survival rates were 88% and 75.5%, respectively. The leading adverse event was myelosuppression. Incidence of grade 3-4 leukocytopenia, neutropenia, and lymphocytopenia was 55%, 67%, and 91%, respectively. The most frequent nonhematological adverse events were CMV antigenemia and rash (33% and 30%, respectively). Incidence of CMV antigenemia over 10/100,000 white blood cells was significantly lower with LD-DEX than that with HD-DEX (P = 0.0127). In conclusion, RBD showed significant effectiveness for RR indolent B-NHL and MCL.

Randomized phase II study of a bendamustine monotherapy schedule for relapsed or refractory low-grade B-cell non-Hodgkin lymphoma or mantle cell lymphoma (RABBIT-14)

The aim of this randomized phase II study was to improve the treatment delays and discontinuations associated with bendamustine use by comparing the effect of Benda-14 (intravenous bendamustine, 120 mg/m² on days 1 and 15, repeated every 4 weeks for a total of 6 cycles) with those of the standard treatment in relapsed indolent lymphoma and/or mantle cell lymphoma. Forty-six patients were randomly assigned to the treatments from September 2012 to February 2016. Treatment accomplishment rate and median relative dose intensity were similar in both arms: 38 and 63.4% in the Benda-14 arm and 41 and 66.3% in the standard treatment arm, respectively. The overall response rate and median progression-free survival, respectively, were 83% and 21.0 months for Benda-14, and 77% and 15.5 months for the standard treatment. Benda-14 induced favorable responses with less frequent hematological toxicities.

The PARP Inhibitor Veliparib Can Be Safely Added to Bendamustine and Rituximab and Has Preliminary Evidence of Activity in B-Cell Lymphoma

Purpose: The PARP inhibitor veliparib enhances the cytotoxicity of alkylating agents. This phase I study evaluated veliparib with the bifunctional alkylator bendamustine (VB) in patients with relapsed/refractory lymphoma, multiple myeloma, and solid malignancies, with a cohort expansion of VB with rituximab (VBR) in patients with B-cell lymphomas.Experimental Design: This dose-escalation study evaluated safety, pharmacokinetics, and preliminary efficacy of veliparib (20-400 mg twice a day, days 1-7 of 28-day cycle) and bendamustine (70 and 90 mg/m² intravenously, days 1 and 2). A cohort expansion was conducted, which combined veliparib and bendamustine at the maximum tolerated dose (MTD) with rituximab (375 mg/m², day 1) in patients with B-cell lymphomas. Thirty-four patients were treated in seven dose-escalation cohorts and seven patients in the dose-expansion cohort.Results: The MTD was veliparib 300 mg twice daily plus bendamustine 90 mg/m² Dose-limiting toxicities (DLT) were anemia, nausea, hypertension, and hyperhidrosis. Grade ≥3 toxicities included lymphopenia (87.8%), anemia (19.5%), neutropenia (12.2%), thrombocytopenia (9.8%), leukopenia (9.8%), nausea (7.3%), and hypophosphatemia (7.3%). Apparent veliparib clearance was slightly lower than previously reported. Of 14 patients with lymphoma evaluable for response, five of seven (71%) on VB and six of seven (86%) on VBR achieved objective response. One patient with multiple myeloma achieved partial response.Conclusions: VB and VBR were generally well-tolerated. VBR had preliminary clinical activity in patients with B-cell lymphoma, which warrants further investigation in a phase II trial. This trial was registered at www.clinicaltrials.gov as NCT01326702 Clin Cancer Res; 23(15); 4119-26. ©2017 AACR.

Efficacy and safety of ibrutinib in Japanese patients with relapsed or refractory mantle cell lymphoma

In this multicenter, single‐arm, phase II study, the efficacy and safety of ibrutinib were examined in Japanese patients with relapsed or refractory mantle cell lymphoma (MCL). Patients (age ≥20 years) with relapsed or refractory MCL who had progressed after receiving at least one prior treatment regimen, were enrolled. Patients were treated with oral ibrutinib (560 mg once daily; 28‐day cycle) until disease progression (or relapse), unacceptable toxicity, or study end. The primary end‐point was overall response rate. Secondary end‐points included duration of response (DOR), time to response, progression‐free survival (PFS), overall survival, and safety. Of the 16 patients who received treatment, 5 patients discontinued the study (progressive disease, 4; sepsis, 1). Median duration of ibrutinib exposure was 6.5 months (range, 2.8–8.3 months). The overall response rate was 87.5% (90% confidence interval, 65.6–97.7; complete response = 2 [12.5%]; partial response = 12 [75.0%]). Median time to response for all responders (n = 14) was 1.8 months (range, 0.7–5.3 months). The median DOR and PFS were not estimable due to censoring (range: DOR, 1.1–6.4+ months; PFS, 2.8–8.0+ months). Overall survival data were immature due to the limited observation period. A total of 8/16 patients (50%) had at least one grade 3 adverse event (AE), and 5 (31.3%) patients reported serious AEs. The most commonly reported AEs were diarrhea and stomatitis (37.5% each), platelet count decrease (31.3%), and anemia (25%). Overall, orally administered single agent ibrutinib was efficacious with an acceptable safety profile in Japanese patients with relapsed or refractory MCL. Clinical trial registration NCT02169180 (ClinicalTrials.gov).

Retrospective analysis of bendamustine and rituximab use in indolent and mantle cell non-Hodgkin lymphoma based on initial starting dose

The initial dose of bendamustine, an alkylating agent used in treating indolent lymphoma (iNHL) and mantle cell lymphoma, is variable in clinical practice. 134 patients treated with bendamustine and rituximab were evaluated for starting dosage, patient characteristics, toxicities, and clinical outcome. The starting dosage ranged from 50 to 90 mg/m². Lower starting dosage (<90 mg/m²) was associated with relapsed disease, increased age and worse performance status (PS), histologic subtype other than follicular lymphoma, baseline renal impairment, and cytopenias. No significant difference was observed in toxicities between patients treated with 90 mg/m² compared with lower doses. The starting dose of 90 mg/m² was associated with a higher complete response rate (56% vs. 29%) and longer progression free survival (PFS) (39.5 months vs. 19.7 months). However, in a multivariable model, the higher starting dose was not associated with longer PFS in those with similar age, histology, PS, and number of prior therapies.

Determination and characterization of two degradant impurities in bendamustine hydrochloride drug product

Bendamustine hydrochloride is an alkylating antitumor agent with a good efficacy in the treatment of chronic lymphocytic leukemia (CLL) and B-cell non-Hodgkin's lymphoma (B-NHL). Under the stressed conditions, two degradant impurities in bendamustine hydrochloride drug product were detected by high-performance liquid chromatography. These two degradant impurities were isolated from preparative liquid chromatography, and were further characterized using Q-TOF/MS and nuclear magnetic resonance (NMR). Based on the MS and NMR spectral data, they were characterized as 4-[5-(2-chloro-ethylamino)-1-methyl-1H-benzoimidazol-2-yl] butyric acid hydrochloride (impurity-A) and 4-{5-[[2-(4-{5-[bis-(2-chloroethyl) amino]-1-methyl-1H-benzoimidazol-2-yl}-butyryloxy)-ethyl]-(2-chloroethyl)amino]-1-methyl-3a, 7a-dihydro-1H-benzoimidazol-2-yl} butyric acid hydrochloride (impurity-B). Isolation, structural elucidation of these two impurities by spectral data (Q-TOF/MS, (1)H NMR, (13)C NMR, D2O exchange NMR and two-dimensional NMR) and the probable formation mechanism of the impurities were discussed.

Increased number of peripheral CD8+ T cells but not eosinophils is associated with late-onset skin reactions caused by bendamustine

Bendamustine is a chemotherapeutic drug that has recently come to be used frequently in the treatment of indolent B cell lymphomas. Skin toxicity is recognized as one of its characteristic side effects, but detailed information on such reactions has not yet been obtained. To clarify the clinical features of skin toxicity associated with bendamustine, we retrospectively analyzed skin reactions that developed in patients treated with bendamustine and rituximab (BR). Of 34 patients treated with 3-6 cycles of BR, 11 developed late-onset, persistent skin eruptions. These patients demonstrated increases in CD8(+) T cell number and CD8(+):CD4(+) cell ratio at the end of chemotherapy. In contrast, peripheral eosinophil count was not associated with such adverse events, whereas eosinophil infiltration was frequently observed in the skin. Patients with skin reactions tended to have higher seropositivity of hepatitis B core antibody, and multiplex viral screening PCR of the frozen sera demonstrated cytomegalovirus-DNA in some of the eruption-positive patients. It is speculated that inappropriate activation of CD8(+) T cells by latently infected pathogens may be one of the triggers of late-onset skin reactions caused by bendamustine.

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.

A phase II study of bendamustine plus rituximab in Japanese patients with relapsed or refractory indolent B-cell non-Hodgkin lymphoma and mantle cell lymphoma previously treated with rituximab: BRB study

To evaluate the efficacy and safety of a combined regimen of bendamustine (B) and rituximab (R) in Japanese patients with relapsed/refractory (r/r) indolent B-cell non-Hodgkin lymphomas (B-NHLs) and mantle cell lymphoma (MCL). Patients aged 20-79 years with pathologically confirmed B-NHLs or MCL, which were r/r after 1-2 R-containing regimens, were included in this study. The BR regimen consisted of B (90 mg/m(2)) for two consecutive days and R (375 mg/m(2)) on day 1, 2, or 3. The course was repeated every 4 weeks for up to four cycles. Fifty-three patients were enrolled in this study and analyzed. The diagnosis included follicular lymphoma (FL) (77 %), mucosa-associated lymphoid tissue lymphoma (13 %) and others (10 %). Forty-seven (90 %) patients completed four cycles of treatment as per schedule. Best overall response rate (ORR) and complete response rate (CRR) was 94 and 71 %, respectively (for FL, ORR 95 % and CRR 80 %). The treatment was well tolerated and the primary toxicity was myelosuppression; the incidence of grade 3/4 leukopenia and neutropenia were 42 and 40 %, respectively. There were no grade 5 toxicities. The BR regimen is safe in Japanese patients with r/r indolent B-NHLs and MCL, and is effective for those with r/r indolent B-NHLs. For the evaluation of late toxicity, especially infection, longer follow-up of this cohort is needed.

Treatment of follicular lymphoma

Follicular lymphoma (FL) is the most common subtype of indolent lymphomas. Several lines of evidence suggest that the prognosis of patients with FL has improved since the introduction of rituximab, although cure cannot be achieved. Although the treatment paradigm for FL has changed over the past decade with the introduction of rituximab and other agents, there is still no standard therapy to fit all patients. Instead, treatment decisions are made taking into consideration disease status (stage, tumor burden, and presence of symptoms) and patient factors including patient preferences. Rituximab-containing chemotherapy such as R-CHOP, R-CVP, and bendamustine plus rituximab is usually recommended for symptomatic patients. However, optimal rituximab-containing chemotherapy has not been established. Rituximab maintenance is one of the post-induction options for patients responding to first-line chemoimmunotherapy. For patients without symptoms and low-tumor burden, both expectant management (watchful waiting) and rituximab monotherapy are reasonable options. A very limited proportion of patients with FL are diagnosed at stage I with rigorous staging using bone marrow biopsy and whole-body imaging with computed tomography (CT) and/or positron emission tomography/CT. Although local radiotherapy has been the standard approach for these patients, its role is being questioned. Patients with FL who achieve remission eventually relapse and require salvage therapy. The salvage regimen should be chosen taking into account previous treatment and its response duration. Moreover, the presence of histological transformation should be assessed.

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.

Clinical efficacy and safety in relapsed/refractory mantle cell lymphoma: a systematic literature review

A systematic literature review was performed to collect and review information on the clinical efficacy and safety of treatments for relapsed/refractory (R/R) mantle cell lymphoma (MCL), with a meta-analysis, if possible. PubMed, Embase, and the Cochrane Library were searched for studies published in English from January 1, 1997, to August 2, 2012. Conference proceedings, bibliographic reference lists of included articles, recent reviews, and ClinicalTrials.gov were searched for phase II to IV studies displaying results. Studies were included if they reported on patients with R/R MCL who were ineligible to receive high-dose chemotherapy with stem cell transplant. Studies of patients with several non-Hodgkin lymphoma subtypes were only included if they reported MCL outcomes separately. We identified 59 studies in R/R MCL. Forty distinct treatment regimens were evaluated. Thirty studies included more than 15 patients with R/R MCL. Six studies were comparative (including 5 randomized controlled trials [RCTs]); 53 were single-arm. There were no common treatments among the RCTs; therefore, a meta-analysis was not feasible. Thirty-one of 59 studies reported baseline data for patients with R/R MCL. Of the 30 studies with > 15 patients with R/R MCL, 30 reported overall response rate data, 14 reported progression-free survival (PFS), and 12 reported overall survival (OS). The small number of RCTs in R/R MCL precludes identifying an optimal treatment. Small sample sizes, infrequent reporting of OS and PFS, and limited information on patient characteristics made a comparison of results difficult. High-quality comparative studies of novel therapies that have the potential to demonstrate OS advantages in R/R MCL are needed.

A multicentre phase II study of vorinostat in patients with relapsed or refractory indolent B-cell non-Hodgkin lymphoma and mantle cell lymphoma

Although initial rituximab-containing chemotherapies achieve high response rates, indolent B-cell non-Hodgkin lymphoma (B-NHL), such as follicular lymphoma (FL), is still incurable. Therefore, new effective agents with novel mechanisms are anticipated. In this multicentre phase II study, patients with relapsed/refractory indolent B-NHL and mantle cell lymphoma (MCL) received vorinostat 200 mg twice daily for 14 consecutive days in a 21-d cycle until disease progression or unacceptable toxicity occurred. The primary endpoint was overall response rate (ORR) in FL patients and safety and tolerability in all patients. Secondary endpoints included progression-free survival (PFS). Fifty-six eligible patients were enrolled; 50 patients (39 with FL, seven with other B-NHL, and four with MCL) were evaluable for ORR, and 40 patients had received rituximab-containing prior chemotherapeutic regimens. For the 39 patients with FL, the ORR was 49% [95% confidence interval (CI): 32·4, 65·2] and the median PFS was 20 months (95% CI: 11·2, 29·7). Major toxicities were manageable grade 3/4 thrombocytopenia and neutropenia. Vorinostat offers sustained antitumour activity in patients with relapsed or refractory FL with an acceptable safety profile. Further investigation of vorinostat for clinical efficacy is warranted.

Pharmacokinetics and excretion of 14C-bendamustine in patients with relapsed or refractory malignancy

BACKGROUND

Bendamustine is an alkylating agent with clinical activity against a variety of hematologic malignancies and solid tumors. To assess the roles of renal and hepatic drug elimination pathways in the excretion and metabolism of bendamustine, a mass balance study was performed in patients with relapsed or refractory malignancies.

METHODS

A single 60-minute intravenous dose of 120 mg/m(2), 80-95 μCi (14)C-bendamustine hydrochloride was administered to six patients, followed by collection of blood, urine, and fecal samples at specified time points up to day 8 or until the radioactivity of the 24-hour urine and fecal collections was below 1% of the administered dose (whichever was longer). Total radioactivity (TRA) was measured in all samples, and concentrations of unchanged bendamustine and its metabolites γ-hydroxy-bendamustine (M3), N-desmethyl-bendamustine (M4), and dihydroxy bendamustine (HP2) were determined in plasma and urine, using validated liquid chromatography-tandem mass spectrometry methods.

RESULTS

The mean recovery of TRA in excreta was 76% of the radiochemical dose. Approximately half of the administered dose was recovered in urine and a quarter in feces. Less than 5% of the administered dose was recovered in urine as unchanged bendamustine. Bendamustine clearance from plasma was rapid, with a half-life of ~40 minutes. Plasma concentrations of M3, M4, and HP2 were very low relative to bendamustine concentrations. Plasma levels of TRA were higher and more sustained as compared with plasma concentrations of bendamustine, M3, M4, and HP2, suggesting the presence of one or more longer-lived (14)C-bendamustine-derived compounds. Fatigue (50%) and vomiting (50%) were the most frequent treatment-related adverse events. A grade 3/4 absolute lymphocyte count decrease occurred in all patients at some point during the study.

CONCLUSION

Bendamustine is extensively metabolized, with subsequent excretion in both urine and feces. Accumulation of bendamustine is not anticipated in cancer patients with renal or hepatic impairment, because of the dose administration schedule and short half-life.

Bendamustine and rituximab in relapsed and refractory hairy cell leukemia

PURPOSE

To determine tolerability and for the first time explore efficacy of bendamustine-rituximab (BR) in multiply relapsed/refractory hairy cell leukemia (HCL), using two different dose levels of bendamustine.

EXPERIMENTAL DESIGN

Patients with HCL with ≥2 prior therapies requiring treatment received rituximab 375 mg/m(2) days 1 and 15 plus bendamustine 70 (n = 6) or 90 (n = 6) mg/m(2), days 1 and 2, for six cycles at 4-week intervals.

RESULTS

At 70 and 90 mg/m(2)/dose of bendamustine, overall response rate was 100%, with three (50%) and four (67%) complete remissions (CR) in each respective group. Minimal residual disease (MRD) was absent in 67% and 100% of CRs, respectively. All six without MRD remain in CR at 30 to 35 (median, 31) months of follow-up. Soluble CD22 and CD25 levels decreased with all responses, with median values decreasing from 17.7 and 42 ng/mL at baseline to undetectable and 2 ng/mL after CR, respectively (P < 0.001). Of 12 patients receiving 72 cycles of BR, the most common toxicities were hematologic, including thrombocytopenia (83%), lymphopenia (75%), leukopenia (58%), and neutropenia (42%). Grade III and IV hematologic toxicity included lymphopenia and thrombocytopenia (each 75%), leukopenia (58%), and neutropenia (25%). No significant dose-related differences were detected in response or toxicity.

CONCLUSION

BR has significant activity in HCL. Bendamustine at either 70 or 90 mg/m(2)/dose was highly effective in multiply relapsed/refractory HCL and could be considered for achieving durable CRs without MRD in patients after failure of standard therapies. As it was not dose-limiting, 90 mg/m(2)/dose was chosen for future testing.

Multicenter Phase II Study of Bendamustine Plus Rituximab in Patients With Relapsed or Refractory Diffuse Large B-Cell Lymphoma

Purpose

Effective and less aggressive therapies are required for patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) who are not eligible for or have undergone autologous stem-cell transplantation (ASCT). The present phase II study assessed the efficacy and safety of bendamustine plus rituximab (BR) in this population.

Patients and Methods

Patients with relapsed or refractory DLBCL treated with one to three prior chemotherapy regimens received rituximab 375 mg/m2 intravenous (IV) infusion on day 1 and bendamustine 120 mg/m2 by IV infusion on days 2 and 3 of each 21-day cycle for up to six cycles. The primary end point was overall response rate (ORR), and the secondary end points were complete response (CR) rate, progression-free survival (PFS), and safety.

Results

Sixty-three patients were enrolled, and 59 received BR. The median age was 67 years (range, 36 to 75 years), and 62.7% of patients were 65 years of age or older. Fifty-seven patients (96.6%) were previously treated with rituximab-containing chemotherapy. The ORR was 62.7% (95% CI, 49.1% to 75.0%), with a CR rate of 37.3% (95% CI, 25.0% to 50.9%). The ORRs were comparable between patients ≥ 65 years of age and less than 65 years (62.2% and 63.6%, respectively). The median PFS was 6.7 months (95% CI, 3.6 to 13.7 months). The most frequently observed grade 3 or 4 adverse events were hematologic: lymphopenia (78.0%), neutropenia (76.3%), leukopenia (72.9%), CD4 lymphopenia (66.1%), and thrombocytopenia (22.0%).

Conclusion

BR is a promising salvage regimen for patients with relapsed or refractory DLBCL after rituximab-containing chemotherapy, warranting further investigation.

Non-gastric advanced mucosa-associated lymphoid tissue (MALT) lymphoma has worse prognosis than gastric MALT lymphoma even when treated with rituximab-containing chemotherapy

The aim of this study was to assess the clinical characteristics, treatment results, and analyze the prognostic factors among patients with extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma). We retrospectively reviewed 98 patients with MALT lymphoma consecutively diagnosed at the Cancer Institute Hospital. Eighty-one patients (82%) had localized disease and 17 patients (17%) had advanced disease. The primary site was gastric in 52, and extra-gastric in 46. With a median follow-up of 40 months, the estimated 3-year overall survival (OS) and progression free survival (PFS) of the entire group were 100% and 89%, respectively. Three-year PFS was significantly better in patients with gastric lymphoma than in those with non-gastric lymphoma (95% vs. 82%, p = 0.043). Patients with localized disease had significantly better 3-year PFS than those with advanced disease (94% vs. 73%, p = 0.026). Upon multivariate analysis, non-gastric lymphoma retained prognostic significance for PFS.

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

Bendamustine is approved in the United States for relapsed indolent lymphoma. However, it has not been widely studied in mantle cell lymphoma (MCL). We retrospectively reviewed the records of all patients with MCL who were treated with bendamustine at three centers. The primary endpoint was overall response rate (ORR). Thirty patients with MCL received bendamustine, 25 for relapsed disease. After a median follow-up of 12 months, there were 15 complete responses (CRs) with an ORR of 83% (95% confidence interval [CI] 70-97%). Factors significantly associated with longer survival were achieving a CR and classical (versus blastic) variant of MCL. Grade 3 or 4 neutropenia, anemia and thrombocytopenia occurred in 23%, 3% and 20%, respectively. There was one case of progressive multifocal leukoencephalopathy 10 months after therapy completion. Bendamustine in combination with rituximab demonstrated a high response rate in this study of patients with predominantly relapsed MCL.

Novel therapies for aggressive B-cell lymphoma

Aggressive B-cell lymphoma (BCL) comprises a heterogeneous group of malignancies, including diffuse large B-cell lymphoma (DLBCL), Burkitt lymphoma, and mantle cell lymphoma (MCL). DLBCL, with its 3 subtypes, is the most common type of lymphoma. Advances in chemoimmunotherapy have substantially improved disease control. However, depending on the subtype, patients with DLBCL still exhibit substantially different survival rates. In MCL, a mature B-cell lymphoma, the addition of rituximab to conventional chemotherapy regimens has increased response rates, but not survival. Burkitt lymphoma, the most aggressive BCL, is characterized by a high proliferative index and requires more intensive chemotherapy regimens than DLBCL. Hence, there is a need for more effective therapies for all three diseases. Increased understanding of the molecular features of aggressive BCL has led to the development of a range of novel therapies, many of which target the tumor in a tailored manner and are summarized in this paper.

Bendamustine: safety and efficacy in the management of indolent non-hodgkins lymphoma

Bendamustine (Treanda, Ribomustin) was recently approved by the US Food and Drug Administration (FDA) for treatment of patients with rituximab refractory indolent lymphoma and is expected to turn into a frontline therapy option for indolent lymphoma. This compound with amphoteric properties was designed in the former Germany Democratic Republic in 1960s and re-discovered in 1990s with multiple successive well-designed studies. Bendamustine possesses a unique mechanism of action with potential antimetabolite properties, and only partial cross-resistance with other alkylators. Used in combination with rituximab in vitro, bendamustine shows synergistic effects against various leukemia and lymphoma cell lines. In clinical studies, bendamustine plus rituximab is highly effective in patients with relapsed-refractory indolent lymphoma, inducing remissions in 90% or more and a median progression-free survival of 23-24 months. The optimal dosing and schedule of bendamustine administration is largely undecided and varies among studies. Results of ongoing trials and dose-finding studies will help to further help ascertain the optimal place of bendamustine in the management of indolent NHL.