Bendamustine (Treanda) displays a distinct pattern of cytotoxicity and unique mechanistic features compared with other alkylating agents

Comparable efficacy of oral bendamustine versus intravenous administration in treating hematologic malignancies

PURPOSE

The purpose of this study was to analyze potential differences in antitumor efficacy and pharmacokinetics between intravenous (IV) bendamustine and a novel orally administered (PO) bendamustine agent that is utilizing the beneficial properties of superstaturated solid dispersions formulated in nanoparticles.

METHODS

Pharmacokinetics of IV versus PO bendamustine were determined by analysis of plasma samples collected from NSG mice treated with either IV or PO bendamustine. Plasma samples were analyzed using liquid chromatography-mass spectrometry following a liquid-liquid extraction to determine peak bendamustine concentration, area under the concentration-time curve, and the half-life in-vivo. In-vitro cytotoxicity of bendamustine against human non-Hodgkin Burkitt's Lymphoma (Raji), multiple myeloma (MM.1s), and B-cell acute lymphoblastic leukemia (RS4;11) cell lines was determined over time using MTS assays. Luciferase-tagged versions of the aforementioned cell lines were used to determine in-vivo bendamustine cytotoxicity of IV versus PO bendamustine at two different doses.

RESULTS

Bendamustine at a high dose in-vitro causes cell death. There was no significant difference in antitumor activity between IV and novel PO bendamustine at a physiologically relevant concentration in all three xenograft models. In-vivo pharmacokinetics showed the oral bioavailability of bendamustine in mice to be 51.4%.

CONCLUSIONS

The novel oral bendamustine agent tested exhibits good oral bioavailability and systemic exposure for in-vivo antitumor efficacy comparable to IV bendamustine. An oral bendamustine formulation offers exciting clinical potential as an additional method of administration for bendamustine and warrants further evaluation in clinical studies.

Methylation of PLK-1 Potentially Drives Bendamustine Resistance in Leukemia Cells

BACKGROUND

Drug resistance remains a significant impediment in leukemia treatment. While Bendamustine hydrochloride (BH) stands out as a promising therapeutic agent for non-Hodgkin's lymphoma and mantle cell lymphoma, the mechanisms of resistance to BH are not yet fully understood. Our study focuses on elucidating the mechanisms behind bendamustine resistance in leukemia cells, with a specific emphasis on epigenetics.

METHODS

Bendamustine-resistant cells were cultivated from human B cell lymphoblastic leukemia cell lines through systematic and sustained exposure to bendamustine, using the limiting dilution method. Gene expression was assessed via real-time polymerase chain reaction, while the expression of the multidrug resistance protein 1 (MDR1) was evaluated using flow cytometry.

RESULTS

Bendamustine-resistant leukemia cells exhibited a decreased RNA expression level for Polo-like kinase-1 (PLK-1). Notably, after treatment with the demethylating agent 5-aza-2'-deoxycytidine, PLK-1 gene expression surged significantly, enhancing bendamustine's cytotoxicity in the resistant leukemia cells. However, MDR1 expression, as determined by flow cytometry, remained consistent between parental and bendamustine-resistant leukemia cells.

CONCLUSIONS

Our findings indicate that the methylation of the PLK-1 gene plays a pivotal role in modulating PLK-1 expression and is central to the development of bendamustine resistance in leukemia cells.

DNA Adducts in Cancer Chemotherapy

DNA adducting drugs, including alkylating agents and platinum-containing drugs, are prominent in cancer chemotherapy. Their mechanisms of action involve direct interaction with DNA, resulting in the formation of DNA addition products known as DNA adducts. While these adducts are well-accepted to induce cancer cell death, understanding of their specific chemotypes and their role in drug therapy response remain limited. This perspective aims to address this gap by investigating the metabolic activation and chemical characterization of DNA adducts formed by the U.S. FDA-approved drugs. Moreover, clinical studies on DNA adducts as potential biomarkers for predicting patient responses to drug efficacy are examined. The overarching goal is to engage the interest of medicinal chemists and stimulate further research into the use of DNA adducts as biomarkers for guiding personalized cancer treatment.

Comparable Efficacy of Oral Bendamustine versus Intravenous Administration in Treating Hematologic Malignancies

Purpose

The purpose of this study was to analyze potential differences in antitumor efficacy and pharmacokinetics between intravenous (IV) bendamustine (BEN) and a novel orally administered bendamustine agent (PO) that is utilizing the beneficial properties of superstaturated solid dispersions formulated in nanoparticles.

Methods

Pharmacokinetics of IV versus PO BEN were determined by analysis of plasma samples collected from NSG mice treated with either IV or PO BEN. Plasma samples were analyzed using liquid chromatography-mass spectrometry (LC/MS/MS) following a liquid-liquid extraction to determine peak BEN concentration (Cmax), area under the concentration-time curve (AUC) and the half-life (t1/2) in-vivo. in-vitro cytotoxicity of BEN against human non-Hodgkin's Burkitt's Lymphoma (Raji), multiple myeloma (MM.1s), and B-cell acute lymphoblastic leukemia (RS4;11) cell lines was determined over time using MTS assays. Luciferase-tagged versions of the aforementioned cell lines were used to determine in-vivo BEN cytotoxicity of IV versus PO BEN at two different doses.

Results

Bendamustine at a high dose in-vitro causes cell death. There was no significant difference in antitumor efficacy between IV and novel PO BEN at a physiologically relevant concentration in all three xenograft models. In-vivo pharmacokinetics showed the oral bioavailability of BEN in mice to be 51.4%.

Conclusions

The novel oral BEN agent tested exhibits good oral bioavailability and systemic exposure for in-vivo antitumor efficacy comparable to IV BEN. An oral BEN formulation offers exciting clinical potential as an additional method of administration for bendamustine and warrants further evaluation in clinical studies.

Synthesis and application of small molecules approved for the treatment of lymphoma

Lymphoma is a form of cancer that impacts the lymphatic system, which plays a crucial role in defending the body against infections and illnesses. It is characterized by the atypical proliferation of lymphocytes, a type of white blood cell, which can form tumors in the lymph nodes, bone marrow, spleen, etc. Lymphoma is usually treated using a combination of targeted therapy, chemotherapy, and radiation therapy. In recent years, there has been a growing interest in the development of new drugs to treat lymphoma, which has led to the discovery of several promising compounds. The primary targets for lymphoma treatment have been identified as Bruton's tyrosine kinase (BTK), phosphoinositide3-kinase (PI3K), histone deacetylase (HDAC), and DNA polymerase (POLA). This review aims to provide an overview of the clinical applications and synthesis of several notable drugs approved to treat lymphoma, to expedite the exploration of more potent novel medications for the management of lymphoma.

BendaEAM versus BEAM as conditioning regimen for ASCT in patients with relapsed lymphoma (BEB): a multicentre, randomised, phase 2 trial

Background

Replacement of carmustine (BCNU) in the BEAM regimen (BCNU, etoposide, cytarabine, melphalan) with bendamustine (BendaEAM) before autologous stem cell transplantation (ASCT) is feasible in lymphoma. However, randomised trials are lacking. Here, we present the first trial addressing this topic.

Methods

This multicentre, randomised, phase 2 study (BEB-trial) conducted at four haematological centres in Austria and Switzerland compares BEAM with BendaEAM in patients with relapsed lymphoma. Both regimens were administered intravenously before ASCT, in BEAM according to the standard protocol (300 mg/m2 BCNU on day -6), in BendaEAM, BCNU was replaced by 200 mg/m2 bendamustine given on days -7 and -6. Eligible patients were aged 18-75 years and had mantle cell lymphoma, diffuse large B-cell lymphoma, or follicular lymphoma in first or second remission or chemosensitive relapse. The primary endpoint of the study was to evaluate whether replacement of BCNU by bendamustine reduces lung toxicity, defined as a decrease of the diffusion capacity of the lung for carbon monoxide by at least 20% at three months after ASCT. Data analyses were performed on an intention-to-treat basis. This study is registered with ClinicalTrials.gov, number NCT02278796, and is complete.

Findings

Between April 20, 2015, and November 28, 2018, 108 patients were enrolled; of whom 53 were randomly assigned to receive BendaEAM (36 male, 17 female) and 55 to receive BEAM (39 male, 16 female). All patients engrafted rapidly. Lung toxicity did not differ between groups (BendaEAM: n = 8, 19.5%; BEAM: n = 11, 25.6%; risk difference = -6.1%: 95% confidence interval: -23.9% to 11.7%). Acute toxicities of at least grade 3 were comparable in both groups (BendaEAM: 35.8%, BEAM: 30.9%). Overall survival (BendaEAM: 92.5%, BEAM: 89.1%) and complete remission (BendaEAM: 76.7%, BEAM: 74.3%) after 1 year (median follow-up: 369 days) were similar. No difference in quality of life was observed.

Interpretation

Results were similar for both regimens in terms of survival and response rates. A phase 3 non-inferiority study is required to investigate whether BendaEAM can be considered as an alternative to BEAM.

Funding

Mundipharma.

Has the shortage of fludarabine altered the current paradigm of lymphodepletion in favor of bendamustine?

The most common lymphodepletion regimen used prior to infusion of chimeric antigen receptor-T cells (CAR-T) is cyclophosphamide (CY) in combination with fludarabine (Flu) (CY-FLU). While cyclophosphamide (CY) possesses lymphotoxic effects, it concurrently preserves regulatory T cell activity, potentially affecting the efficacy of CAR-T cells. Moreover, the use of fludarabine (FLU) has been linked to neurotoxicity, which could complicate the early detection of immune effector cell-associated neurotoxicity syndrome (ICANS) observed in CAR-T cell therapy. Given the ongoing shortage of FLU, alternative lymphodepleting agents have become necessary. To date, only a limited number of studies have directly compared different lymphodepleting regimens, and most of these comparisons have been retrospective in nature. Herein, we review the current literature on lymphodepletion preceding CAR-T cell therapies for lymphoid hematologic malignancies, with a specific focus on the use of bendamustine (BEN). Recent evidence suggests that administering BEN before CAR-T cell infusion yields comparable efficacy, possibly with a more favorable toxicity profile when compared to CY-FLU. This warrants further investigation through randomized prospective studies.

Studying the Interaction between Bendamustine and DNA Molecule with SERS Based on AuNPs/ZnCl2/NpAA Solid-State Substrate

Bendamustine (BENDA) is a bifunctional alkylating agent with alkylating and purinergic antitumor activity, which exerts its anticancer effects by direct binding to DNA, but the detailed mechanism of BENDA-DNA interaction is poorly understood. In this paper, the interaction properties of the anticancer drug BENDA with calf thymus DNA (ctDNA) were systematically investigated based on surface-enhanced Raman spectroscopy (SERS) technique mainly using a novel homemade AuNPs/ZnCl2/NpAA (NpAA: nano porous anodic alumina) solid-state substrate and combined with ultraviolet-visible spectroscopy and molecular docking simulation to reveal the mechanism of their interactions. We experimentally compared and studied the SERS spectra of ctDNA, BENDA, and BENDA-ctDNA complexes with different molar concentrations (1:1, 2:1, 3:1), and summarized their important characteristic peak positions, their peak position differences, and hyperchromic/hypochromic effects. The results showed that the binding modes include covalent binding and hydrogen bonding, and the binding site of BENDA to DNA molecules is mainly the N7 atom of G base. The results of this study help to understand and elucidate the mechanism of BENDA at the single-molecule level, and provide guidance for the further development of effective new drugs with low toxicity and side effects.

Revisiting the Role of Alkylating Agents in Multiple Myeloma: Up-to-Date Evidence and Future Perspectives

From the 1960s to the early 2000s, alkylating agents (e.g., melphalan, cyclophosphamide, and bendamustine) remained a key component of standard therapy for newly-diagnosed or relapsed/refractory multiple myeloma (MM). Later on, their associated toxicities (including second primary malignancies) and the unprecedented efficacy of novel therapies have led clinicians to increasingly consider alkylator-free approaches. Meanwhile, new alkylating agents (e.g., melflufen) and new applications of old alkylators (e.g., lymphodepletion before chimeric antigen receptor T-cell [CAR-T] therapy) have emerged in recent years. Given the expanding use of antigen-directed modalities (e.g., monoclonal antibodies, bispecific antibodies, and CAR-T therapy), this review explores the current and future role of alkylating agents in different treatment settings (e.g., induction, consolidation, stem cell mobilization, pre-transplant conditioning, salvage, bridging, and lymphodepleting chemotherapy) to ellucidate the role of alkylator-based regimens in modern-day MM management.

Combination of bendamustine-azacitidine against Syk target of breast cancer: an in silico study

Breast cancer (BC) is the most serious and second leading cause of death in women worldwide. When breast cancer is diagnosed and treated early, the chance of long-term survival is up to 90%. On the other hand, 90% of BC patient deaths are due to metastasis and a lack of effective early diagnosis. The existing conventional chemotherapy provides negative feedback due to transportation barriers towards the action sites, multidrug resistance, poor bio-availability, non-specific delivery and systemic side effects on the healthy tissue. Syk protein Kinase has been reported in BC, as a tumor modulator, providing a pro-survival signal and also by restricting epithelial-mesenchymal transition, enhancing cell-cell interactions and inhibiting migration. In the present study, we explored the possibility of targeting BC by attenuating Syk protein Kinase. Hence, we have conjugated the hydrophobic Bendamustine (BEN) and hydrophilic Azacitidine (AZA) anticancer drugs to evaluate their efficacy against BC. The native drugs (BEN and AZA) and designed drug-drug conjugate (BEN-AZA) were docked with Syk protein. Then, the docked complex was performed for Binding Free Energy and Molecular Dynamics Simulations. Furthermore, DFT and ADME properties were carried out. The results revealed that the designed drug-drug conjugate has a better docking score, ΔGbind and admirable stability throughout the simulation when compared with native drugs. In DFT and ADME analyses, the designed drug-drug conjugate has shown good stereo electronic features and pharmaceutical relevant parameters than that of native drugs. The overall results suggested that the designed drug-drug conjugate may be a suitable candidate for BC treatment.Communicated by Ramaswamy H. Sarma.

Oral formulation of bendamustine hydrochloride for patients with advanced solid tumors; a phase 1 study

To determine the maximum tolerated dose (MTD) and recommended dose (RD) of orally-administered bendamustine in Japanese patients with advanced solid tumors. The optimal dosing schedule, safety, pharmacokinetics, and preliminary antitumor effects were also evaluated. A multicenter, open-label trial with a standard 3 + 3 design and dose escalation by dose-limiting toxicity (DLT) was conducted. The treatment schedules were once daily for 7, 14, and 21 days every 3 weeks as one cycle. The total dose per cycle was increased from 175 to 840 mg/m². Eighteen patients were enrolled in this study. DLT occurred in one of six patients at 75 mg/m²/day × 7 days, and one of three patients at 37.5 mg/m²/day × 14 days and 25 mg/m²/day × 21 days. However, the delayed recovery from a decrease in neutrophil or platelet count hampered the start of subsequent treatment cycles, and the trend was more prominent at 37.5 mg/m²/day × 14 days and 25 mg/m²/day × 21 days than in 75 mg/m²/day × 7 days. MTD was determined as 75 mg/m²/day × 7 days to allow acceptable hematologic recovery. The pharmacokinetics of orally-administered bendamustine were generally dose-dependent; however, the inter-individual variability is relatively large. The major adverse events were hematologic toxicities; gastrointestinal disorders were generally mild. Adverse drug reactions did not lead to the discontinuation of the drug. A partial response was observed in two of six patients (prostatic small cell carcinoma and thymic carcinoma) at 75 mg/m²/day × 7 days. The RD and optimal dosing schedule of orally-administered bendamustine was 75 mg/m² once daily for 7 days every 3 weeks for the treatment of advanced solid tumors. (Trial registration number ClinicalTrials.gov NCT03604679. Registration date July 27, 2018).

Benzimidazole and its derivatives as cancer therapeutics: The potential role from traditional to precision medicine

Cancer is the second leading cause of mortality globally which remains a continuing threat to human health today. Drug insensitivity and resistance are critical hurdles in cancer treatment; therefore, the development of new entities targeting malignant cells is considered a high priority. Targeted therapy is the cornerstone of precision medicine. The synthesis of benzimidazole has garnered the attention of medicinal chemists and biologists due to its remarkable medicinal and pharmacological properties. Benzimidazole has a heterocyclic pharmacophore, which is an essential scaffold in drug and pharmaceutical development. Multiple studies have demonstrated the bioactivities of benzimidazole and its derivatives as potential anticancer therapeutics, either through targeting specific molecules or non-gene-specific strategies. This review provides an update on the mechanism of actions of various benzimidazole derivatives and the structure‒activity relationship from conventional anticancer to precision healthcare and from bench to clinics.

Molecular design, synthesis and biological evaluation of novel 1,2,5-trisubstituted benzimidazole derivatives as cytotoxic agents endowed with ABCB1 inhibitory action to overcome multidrug resistance in cancer cells

Multidrug resistance (MDR) is a leading cause for treatment failure in cancer patients. One of the reasons of MDR is drug efflux by ATP-binding cassette (ABC) transporters in eukaryotic cells especially ABCB1 (P-glycoprotein). In this study, certain novel 1,2,5-trisubstituted benzimidazole derivatives were designed utilising ligand based pharmacophore approach. The designed benzimidazoles were synthesised and evaluated for their cytotoxic activity towards doxorubicin-sensitive cell lines (CCRF/CEM and MCF7), as well as against doxorubicin-resistant cancer cells (CEM/ADR 5000 and Caco-2). In particular, compound VIII showed a substantial cytotoxic effect in all previously mentioned cell lines especially in doxorubicin-resistant CEM/ADR5000 cells (IC₅₀ = 8.13 µM). Furthermore, the most promising derivatives VII, VIII and XI were tested for their ABCB1 inhibitory action in the doxorubicin-resistant CEM/ADR 5000 subline which is known for overexpression of ABCB1 transporters. The results showed that compound VII exhibited the best ABCB1 inhibitory activity at three tested concentrations (22.02 µM (IC₅₀), 50 µM and 100 µM) in comparison to verapamil as a reference ABCB1 inhibitor. Such inhibition resulted in a synergistic effect and a massive decrease in the IC₅₀ of doxorubicin (34.5 µM) when compound VII was used in a non-toxic dose in combination with doxorubicin in doxorubicin-resistant cells CEM/ADR 5000 (IC_50(Dox+VII) = 3.81 µM). Molecular modelling studies were also carried out to explain the key interactions of the target benzimidazoles at the ABCB1 binding site. Overall the obtained results from this study suggest that 1,2,5-trisubstituted benzimidazoles possibly are promising candidates for further optimisation and development of potential anticancer agents with ABCB1 inhibitory activity and therefore overcome MDR in cancer cells.

Processes in DNA damage response from a whole-cell multi-omics perspective

Technological advances have made it feasible to collect multi-condition multi-omic time courses of cellular response to perturbation, but the complexity of these datasets impedes discovery due to challenges in data management, analysis, visualization, and interpretation. Here, we report a whole-cell mechanistic analysis of HL-60 cellular response to bendamustine. We integrate both enrichment and network analysis to show the progression of DNA damage and programmed cell death over time in molecular, pathway, and process-level detail using an interactive analysis framework for multi-omics data. Our framework, Mechanism of Action Generator Involving Network analysis (MAGINE), automates network construction and enrichment analysis across multiple samples and platforms, which can be integrated into our annotated gene-set network to combine the strengths of networks and ontology-driven analysis. Taken together, our work demonstrates how multi-omics integration can be used to explore signaling processes at various resolutions and demonstrates multi-pathway involvement beyond the canonical bendamustine mechanism.

A phase I/II study of 10-min dosing of bendamustine hydrochloride (rapid infusion formulation) in patients with previously untreated indolent B-cell non-Hodgkin lymphoma, mantle cell lymphoma, or relapsed/refractory diffuse large B-cell lymphoma in Japan

Purpose

This phase I/II clinical study was conducted to examine the safety, tolerability, pharmacokinetics, and efficacy of 10-min dosing of bendamustine in patients with previously untreated indolent B-cell non-Hodgkin lymphoma (iNHL) or mantle cell lymphoma (MCL) (Group 1) and patients with relapsed/refractory diffuse large B-cell lymphoma (rrDLBCL) (Group 2).

Methods

Rituximab 375 mg/m² was administered intravenously every 28 days to Group 1 patients on day 1 and every 21 days to Group 2 patients on day 1. Bendamustine 90 mg/m²/day was administered to the former on days 1 and 2; bendamustine 120 mg/m²/day was administered to the latter on days 2 and 3. Each regimen was delivered up to six cycles for both groups. The primary endpoints were safety and tolerability in Groups 1 and 2, respectively.

Results

Among 37 enrolled patients, safety was assessed in 36. In Group 1 (n = 30), 27 patients (90%) had follicular lymphoma. Adverse events (AEs) were observed in all 30 patients in Group 1. Dose-limiting toxicities were observed in two of six patients in Group 2. Common AEs included lymphocyte count decreased (86.7%, 100%). In Group 1, overall response and complete response rates were 93.1% (95% confidence interval [CI] 77.2–99.2%) and 75.9% (95% CI 56.5–89.7%), respectively. The C_max and AUC of bendamustine tended to be higher in Group 2 than in Group 1.

Conclusions

This study showed that bendamustine is safe, well-tolerated and effective for patients with previously untreated iNHL, MCL or rrDLBCL. Pharmacokinetic data were equivalent to those obtained outside of Japan.

Registration numbers

Registration NCT03900377; registered April 3, 2019.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00280-022-04442-2.

Bendamustine: A review of pharmacology, clinical use and immunological effects (Review)

Bendamustine is an alkylating agent classified into the group of nitrogen mustard analogues, synthesized almost sixty years ago. It was registered in former East Germany in 1971 and approved by the US Food and Drug Administration in 2008 for treatment of chronic lymphocytic leukemia and indolent B-cell non-Hodgkin lymphoma. Considering its beneficial properties in the therapy of relapsed or refractory hematological malignancies, synergistic effects with other antineoplastic agents and increasing recent reports on its immunomodulatory effects, bendamustine has once again gained its justified attention. The uniqueness of bendamustine-mediated effects should be observed keeping in mind its distinctive structure with structural similarities to both alkylating agents and purine analogs. In the present review, the current knowledge on the use of bendamustine in oncology, its pharmacokinetics, mechanism of action and toxicity was summarized. In addition, its immune-modulating effects that have not been fully elucidated so far are emphasized, hoping to encourage further investigations of this unique drug.

Bendamustine in combination with pomalidomide and dexamethasone in relapsed/refractory multiple myeloma: A phase II trial

Treatment of patients with resistant/refractory multiple myeloma (MM) is an unmet need. In this phase II study, we evaluated the role of bendamustine, pomalidomide and dexamethasone combination in this setting. Between February 2020 and December 2021, 28 patients were recruited. Patients received bendamustine 120 mg/m² day 1, pomalidomide 3 mg days 1-21, and dexamethasone 40 mg days 1, 8, 11, 22, regimen given for a maximum of six cycles. The median (range) age of the patients was 54 (30-76) years and 15 (53.6%) were males. Patients had received a median (range) of three (two-six) prior lines and 85.7% were refractory to both lenalidomide and bortezomib. The primary end-point was the overall response rate (ORR) defined as ≥partial response after at least three cycles. Secondary objectives were toxicity, progression-free survival (PFS), time to progression and overall survival (OS). An intent-to-treat analysis was done. An ORR of 57.6% was achieved. Patients with extramedullary myeloma had a better response rate. At a median follow-up of 8.6 months, the median PFS and OS were 6.2 and 9.7 months respectively. Toxicity was manageable; mainly haematological (neutropenia, 46.4%; anaemia, 42.8%; and thrombocytopenia, 7.1%). Bendamustine, pomalidomide and dexamethasone could be a novel combination for the heavily pretreated, lenalidomide-refractory myeloma population.

Feasibility and efficacy of partially replacing post-transplant cyclophosphamide with bendamustine in pediatric and young adult patients undergoing haploidentical bone marrow transplantation

BACKGROUND

Post-transplant cyclophosphamide (PT-CY) is the most widely applied graft-versus-host disease (GvHD) prophylaxis regimen in T-cell replete haploidentical bone marrow transplantation (haplo-BMT). While PT-CY has been met with great success in the haplo-BMT arena by suppressing GvHD, patients without acute GvHD have high relapse rates.

OBJECTIVE

One of the strategies being explored by others to lessen relapse rates is the dose reduction of PT-CY. We have taken a different approach in evaluating whether partially replacing PT-CY with post-transplant bendamustine (PT-BEN) would be advantageous, which is based on our pre-clinical research that delineated several beneficial immunomodulatory properties of BEN.

STUDY DESIGN

We therefore initiated and completed a Phase Ia trial which evaluated the progressive substitution of PT-CY with PT-BEN (NCT02996773). Thirteen patients with high-risk hematologic malignancies have received PT-CY/BEN and their outcomes compared to 31 contemporaneous haplo-BMT recipients treated with the same myeloablative conditioning (MAC) regimens but receiving only PT-CY.

RESULTS

We demonstrate that partial replacement of PT-CY with PT-BEN on day +4 (PT-CY/BEN) is well tolerated and associated with significantly earlier trilineage engraftment. We also show favorable trends to significant improvements in univariate and multivariate analyses, with PT-CY/BEN compared to PT-CY, with respect to chronic GvHD (HR, 0.08; 95% CI, 0.005, 1.11; P=0.06), and GvHD-free-relapse-free survival (GRFS) (HR, 0.22; 95% CI, 0.05, 0.86; P=0.039). Our human trial has transitioned to Phase Ib which will further evaluate the safety and potential benefits of PT-CY/BEN. Herein, we also expand our pediatric, adolescent, and young adult (AYA) experience to 31 patients demonstrating an overall survival (OS), progression-free survival (PFS) and GRFS at 3 years of 85.6%, 76.1% and 58.2%, respectively in a largely racial/ethnic minority cohort.

CONCLUSIONS

PT-CY/BEN appears to be a promising treatment option that requires further evaluation.

Adding bendamustine to melphalan before ASCT improves CR rate in myeloma vs. melphalan alone: A randomized phase-2 trial

Definite cure remains exceptional in myeloma patients even after high-dose chemotherapy (HDCT) with melphalan (Mel) and autologous stem cell transplantation (ASCT). Thus, improving efficacy of HDCT in MM remains an unresolved issue. This randomized phase II trial compared standard 200 mg/m² Mel HDCT to experimental HDCT with 200 mg/m² bendamustine, given both at days −4 and −3, combined with 100 mg/m² melphalan at days −2 and −1 (BenMel) before ASCT as first-line consolidation in myeloma patients. The primary endpoint aimed to identify at least a 15% improvement in the complete remission rate (stringent CR + CR) after HDCT with BenMel compared with Mel alone. A total of 120 MM patients were 1:1 randomized. The rate of sCR/CR after ASCT was higher in BenMel than in Mel treated patients (70.0% vs. 51.7%; p = 0.039). Three patients in the BenMel group (5.0%) had reversible acute renal insufficiency compared with none in Mel patients. Minimal residual disease negativity (<10-5) by flow cytometry was observed in 26 (45.6%) BenMel patients and 22 (37.9%) in the Mel group (p = 0.375). Our data suggest that BenMel HDCT is safe and improves the sCR/CR rate compared with standard Mel alone.

The potential efficacy and mechanism of bendamustine in entra-nodal NK/T cell lymphoma

Bendamustine has been shown to have anti-tumor activities in hematological malignancies, but the role of bendamustine in natural killer (NK)/T cell lymphoma (NKTCL) treatment is unclear. Our study has shown that bendamustine had potent growth-inhibitory and apoptosis-inducing effects on NKTCL cells. Interestingly, we noticed that the combination of either gemcitabine or etoposide results in additive or synergistic cytotoxicity. Bendamustine induced mitochondria-mediated apoptosis in concentration- and time-dependent manners in NKTCL cells, shown as down-regulation of Bcl-2 and activation of cleavage of caspases 3, 7, 9 and poly adenosinediphosphate-ribose polymerase (PARP). Bendamustine arrested NKTCL cells in G2/M phase, with downregulation of expression of cyclin B1 and upregulation of expression of p-cdc2, p-cdc25c and p-P53. Furthermore, we confirmed that bendamustine activated DNA damage response (DDR) directly or through Ataxia Telangiectasia Mutated Protein (ATM)/Chk2 and ATR/Chk1 pathway and increased the intracellular reactive oxygen species (ROS) level in NKTCL cells, which caused G2/M phase arrest and apoptosis. Bendamustine also inhibited phosphorylation of transcriptional factor STAT3, contributing to cell apoptosis and proliferation inhibition. Finally, we verified the effect of bendamustine on NKTCL cells in vivo. It showed that bendamustine dramatically inhibited the growth of the subcutaneous tumor, with no obvious impact on mice weight. These findings demonstrate that bendamustine activates DDR pathway, induces the accumulation of intracellularROS level as well as inhibition of STAT3, leading to cell apoptosis and G2/M cell cycle arrest in NKTCL cells, which indicates that bendamustine dramatically suppressed NKTCL both in vitro and in vivo and provides a potential therapeutic strategy in the treatment of NK/T lymphoma.

Delivery strategies in treatments of leukemia

Leukemia is a hematological malignancy associated with the uncontrolled proliferation of mutant progenitors, suppressing the production of normal blood cells. Current treatments, including chemotherapy, radiotherapy, and immunotherapy, still lead to unsatisfactory results with a 5 year survival rate of only 30-50%. The poor prognosis is related to both disease relapse and treatment-associated toxicity. Delivery strategies can improve the in vivo pharmacokinetics of drugs, navigating the therapeutics to target cells or the tumor microenvironment and reversing drug resistance, which maximizes tumor elimination and alleviates systematic adverse effects. This review discusses available FDA-approved anti-leukemia drugs and therapies with a focus on the advances in the development of anti-leukemia drug delivery systems. Additionally, challenges in clinical translation of the delivery strategies and future research opportunities in leukemia treatment are also included.

Management of relapsed or refractory large B-cell lymphoma in patients ineligible for CAR-T cell therapy

INTRODUCTION

Chimeric antigen receptor T (CAR-T) therapy has revolutionized the treatment of relapsed/refractory large B-cell lymphoma (LBCL). However, patients who are excluded or have no access to CAR-T represent a challenge for clinicians and have generally a dismal outcome. The landscape for this category of patients is constantly evolving: new agents have been approved in the last 2-3 years, alone or in combination, and novel treatment modalities are under investigations.

AREAS COVERED

Thereafter, we reviewed the currently available therapeutic strategies: conventional chemotherapy, Antibody-drug conjugate ADC (mainly polatuzumab and loncastuxumab), bispecific antibodies (CD19/CD3 and focus on novel CD20/CD3 Abs), immunomodulatory drugs (covering tafasitamab and lenalidomide, checkpoint inhibitors mainly in PMBL), small molecules (selinexor, BTK and PI3K inhibitors), and the role of radiotherapy.

EXPERT OPINION

Navigating this scenario, will uncover new challenges, including identifying an ideal sequence for these therapies, the most effective combinations, and search for consistent predictive factors to help selecting the appropriate population of LBCL patients. At present, supporting clinical research for CAR-T ineligible patients, a new and challenging group, must remain a major focus that is complementary to advances in CAR T-cell therapy.

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.

BeEAM conditioning regimen is a safe, efficacious and economical alternative to BEAM chemotherapy

In many stem cell transplant centres, BCNU, etoposide, cytarabine and melphalan (BEAM) high-dose chemotherapy (HDCT) has been replaced by the more economic and available bendamustine, etoposide, cytarabine, melphalan (BeEAM) regimen. However, there is a paucity of information on the efficacy and safety of BeEAM HDCT. We describe our experience with BeEAM HDCT in terms of safety, efficacy and cost-savings. We compare overall and progression-free survival to a cohort of patients previously transplanted at our institution with the older BEAM regimen. We performed a retrospective chart review of 41 lymphoma patients undergoing BeEAM HDCT at the Royal University Hospital in Saskatoon, Saskatchewan between 2015 and 2019 to elicit regimen safety in the first 100 days post-transplant. Furthermore, we calculated overall and progression-free survival and constructed corresponding Kaplan-Meier curves, comparing the results to a historical cohort of BEAM patients (n = 86). Finally, we conducted an economic analysis using the financials available at our centre's pharmacy. With regards to BeEAM HDCT, we report a 100-day transplant-related mortality of 2.4%. Additionally, we report acceptable rates of typhlitis (27%), grade III-IV mucositis (4.9%) and grade III-IV nephrotoxicity (2.4%). In terms of overall and progression-free survival, we found no statistical difference between BeEAM and BEAM (p = 0.296; 0.762, respectively). Finally, our economic analysis revealed a net savings of $21,200 CAD per transplant when BeEAM is used in replacement of BEAM. The acceptable safety profile of BeEAM and its comparable efficacy to BEAM are encouraging for the perseverance of this cost-effective HDCT regimen.

Regulatory Dendritic Cells Induced by Bendamustine Are Associated With Enhanced Flt3 Expression and Alloreactive T-Cell Death

The growth factor Flt3 ligand (Flt3L) is central to dendritic cell (DC) homeostasis and development, controlling survival and expansion by binding to Flt3 receptor tyrosine kinase on the surface of DCs. In the context of hematopoietic cell transplantation, Flt3L has been found to suppress graft-versus-host disease (GvHD), specifically via host DCs. We previously reported that the pre-transplant conditioning regimen consisting of bendamustine (BEN) and total body irradiation (TBI) results in significantly reduced GvHD compared to cyclophosphamide (CY)+TBI. Pre-transplant BEN+TBI conditioning was also associated with greater Flt3 expression among host DCs and an accumulation of pre-cDC1s. Here, we demonstrate that exposure to BEN increases Flt3 expression on both murine bone marrow-derived DCs (BMDCs) and human monocyte-derived DCs (moDCs). BEN favors development of murine plasmacytoid DCs, pre-cDC1s, and cDC2s. While humans do not have an identifiable equivalent to murine pre-cDC1s, exposure to BEN resulted in decreased plasmacytoid DCs and increased cDC2s. BEN exposure and heightened Flt3 signaling are associated with a distinct regulatory phenotype, with increased PD-L1 expression and decreased ICOS-L expression. BMDCs exposed to BEN exhibit diminished pro-inflammatory cytokine response to LPS and induce robust proliferation of alloreactive T-cells. These proliferative alloreactive T-cells expressed greater levels of PD-1 and underwent increased programmed cell death as the concentration of BEN exposure increased. Alloreactive CD4⁺ T-cell death may be attributable to pre-cDC1s and provides a potential mechanism by which BEN+TBI conditioning limits GvHD and yields T-cells tolerant to host antigen.

Current and Novel Alkylators in Multiple Myeloma

A large number of novel treatments for myeloma have been developed and approved; however, alkylating drugs continue to be part of standard regimens. Additionally, novel alkylators are currently being developed. We performed a non-systematized literary search for relevant papers and communications at large conferences, as well as exploiting the authors' knowledge of the field, to review the history, current use and novel concepts around the traditional alkylators cyclophosphamide, bendamustine and melphalan and current data on the newly developed pro-drug melflufen. Even in the era of targeted treatment and personalized medicine, alkylating drugs continue to be part of the standard-of-care in myeloma, and new alkylators are coming to the market.

Bendamustine-induced nephrogenic diabetes insipidus - A case report

INTRODUCTION

In patients with relapsed or refractory lymphoma, high-dose chemoimmunotherapy with subsequent autologous hematopoietic cell transplantation (HCT) is a standard of care. Bendamustine, an alkylating agent, is used in the BeEAM (bendamustine, etoposide, cytarabine, melphalan) protocol for conditioning therapy before autologous HCT in patients with relapsed or refractory lymphoma who are eligible for transplant. There is no consensus regarding an optimal salvage regimen and the approach varies according to toxicity.

CASE REPORT

We present a case of partial nephrogenic diabetes insipidus after receiving bendamustine, as part of the BeEAM protocol.Management and outcome: The patient was managed with parenteral fluid administration and intranasal desmopressin before the condition resolved on its own.

DISCUSSION

We summarize published reports of bendamustine-induced diabetes insipidus.

Real-world evidence of cytomegalovirus reactivation in non-Hodgkin lymphomas treated with bendamustine-containing regimens

Cytomegalovirus (CMV) reactivation during chemotherapy or after organ or hematopoietic stem cell transplantation is a major cause of morbidity and mortality, and the risk of reactivation increases with patients’ age. Bendamustine, an alkylating agent currently used for treatment of indolent and aggressive non-Hodgkin lymphomas, can augment the risk of secondary infections including CMV reactivation. In this real-world study, we described an increased incidence of CMV reactivation in older adults (age >60 years old) with newly diagnosed and relapsed/refractory indolent and aggressive diseases treated with bendamustine-containing regimens. In particular, patients who received bendamustine plus rituximab and dexamethasone were at higher risk of CMV reactivation, especially when administered as first-line therapy and after the third course of bendamustine. In addition, patients with CMV reactivation showed a significant depression of circulating CD4⁺ T cell count and anti-CMV IgG levels during active infection, suggesting an impairment of immune system functions which are not able to properly face viral reactivation. Therefore, a close and early monitoring of clinical and laboratory findings might improve clinical management and outcome of non-Hodgkin lymphoma patients by preventing the development of CMV disease in a subgroup of subjects treated with bendamustine more susceptible to viral reactivation.

Immunomodulatory Effects of Bendamustine in Hematopoietic Cell Transplantation

Bendamustine (BEN) is a unique alkylating agent with efficacy against a broad range of hematological malignancies, although investigations have only recently started to delve into its immunomodulatory effects. These immunomodulatory properties of BEN in the context of hematopoietic cell transplantation (HCT) are reviewed here. Pre- and post-transplant use of BEN in multiple murine models have consistently resulted in reduced GvHD and enhanced GvL, with significant changes to key immunological cell populations, including T-cells, myeloid derived suppressor cells (MDSCs), and dendritic cells (DCs). Further, in vitro studies find that BEN enhances the suppressive function of MDSCs, skews DCs toward cDC1s, enhances Flt3 expression on DCs, increases B-cell production of IL-10, inhibits STAT3 activation, and suppresses proliferation of T- and B-cells. Overall, BEN has a broad range of immunomodulatory effects that, as they are further elucidated, may be exploited to improve clinical outcomes. As such, clinical trials are currently underway investigating new potential applications of BEN in the setting of allogeneic HCT.

Benzimidazole based hybrids against complex diseases: A catalogue of the SAR profile

The fused heterocyclic ring system has been recognized as a privileged structure that is used as a template in medicinal chemistry for drug discovery. Benzimidazole is one of the common scaffolds found in several natural products such as histidine, purines, and an integral part of vitamin B12. This hetero-aromatic bicyclic ring system acts as a pharmacophore in various drugs of therapeutic interest and has a broad spectrum of activity. Literature reports suggest that diversely substituted benzimidazoles possess distinct pharmacological profiles with multi-targeting potential, thereby, an indispensable anchor for the development of novel therapeutic agents against complex diseases such as cancer, malaria, inflammatory disorders, microbial diseases, hypertension, etc. Thus, lots of efforts have been diverted towards exploring the therapeutic potential of benzimidazoles. Despite great efforts made by the research community, still, some multi-factorial diseases continue to progress due to their complex pathophysiology. Under these sets of circumstances, there is a need to explore this nucleus for hybrid designing with multi-targeting potential against complex diseases. Benzimidazole-based hybrids have been reported to treat multifactorial diseases, making it a scaffold of interest for various pharmaceutical companies and research groups. In this write-up, we shed light on the recent pharmacological profiles, various designing strategies, and structure-activity relationships (SAR) of different benzimidazole-based hybrids.

Sequential intensive chemotherapy followed by autologous or allogeneic transplantation for refractory lymphoma

We evaluate the safety of bendamustine as a bridge to stem cell transplantation (SCT) in patients with relapsed/refractory lymphoma and residual disease after salvage therapy. Thirty-four subjects without complete responses (CR) received bendamustine 200 mg/m²/day for 2 days followed 14 days later by SCT. Sixteen subjects in partial remission (PR) with maximal FDG-PET SUVs ≤8 prior to bendamustine received autologous SCT, while 13 with suboptimal responses were allografted. Five subjects did not proceed to transplant. No bendamustine toxicities precluded transplantation and no detrimental effect on engraftment or early treatment-related mortality (TRM) was attributable to bendamustine. At 1 year, 75% of auto-recipients and 31% of allo-recipients were alive with CR. Two subjects in the autologous arm developed therapy-related myeloid neoplasia (t-MN). In conclusion, a bendamustine bridge to SCT can be administered without early toxicity to patients with suboptimal responses to salvage chemotherapy. However this approach may increase the risk of t-MN. (NCT02059239).Supplemental data for this article is available online at here.

Derivatives of nitrogen mustard anticancer agents with improved cytotoxicity

In previous studies, we demonstrated that esters of bendamustine containing a basic moiety are far more cytotoxic anticancer agents than their parent compound and that the substitution of the labile ester moiety by a branched ester or an amide markedly increases stability in the blood plasma. In the current study, we showed that this substitution was bioisosteric. Aiming at increased cytotoxicity, we introduced the same modification to related nitrogen mustards: 6-isobendamustine, chlorambucil, and melphalan. The synthesis was accomplished using the coupling reagents N,N'-dicyclohexylcarbodiimide or 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethylaminium tetrafluoroborate. Cytotoxicity against a panel of diverse cancer cells (carcinoma, sarcoma, and malignant melanoma) was assessed in a kinetic chemosensitivity assay. The target compounds showed cytotoxic or cytocidal effects at concentrations above 1 µM: a striking enhancement over bendamustine and 6-isobendamustine, both ineffective against the selected cancer cells at concentrations up to 50 µM, and a considerable improvement over chlorambucil, showing some potency only against the sarcoma cells. Melphalan was almost as effective as the target compounds-derivatization only provided a small improvement. The novel cytostatics are of interest as model compounds for analyzing a correlation between cytotoxicity and membrane transport and for the treatment of malignancies.

Phase I/II study of bendamustine in combination with ofatumumab, carboplatin, etoposide (BOCE) for relapsed or refractory aggressive B-cell non-Hodgkin lymphoma

We developed an outpatient salvage chemotherapy regimen using bendamustine, ofatumumab, carboplatin and etoposide (BOCE) to treat relapsed/refractory non-Hodgkin lymphoma (RR NHL) in a single-center phase I/II study. Primary objectives were safety, tolerability and overall response rate (ORR). Thirty-five RR NHL patients (57% de novo large cell [DLBCL] or grade 3B follicular [FL], 26% transformed DLBCL, 9% grade 3A FL, 3% mantle cell; median age = 62, median prior therapies = 1) were treated. Median follow-up was 24.1 months. ORR was 69% (CR = 49%, PR = 20% [ORR = 70%, CR = 50%, PR = 20% in the de novo DLBCL/grade 3B FL subgroup]). Median progression-free survival was 5.1 months and overall-survival 26.2 months. Twelve patients subsequently underwent stem cell transplantation. The most common non-hematologic grade 3-4 toxicities were neutropenic fever and hypophosphatemia. There were no treatment-related deaths. In conclusion, BOCE is a safe and effective outpatient salvage regimen for patients with RR NHL and serves as an effective bridge to stem cell transplantation.

Bendamustine-rituximab regimen in untreated indolent marginal zone lymphoma: experience on 65 patients

First line therapy of patients with marginal zone lymphomas (MZL) is not well established and various regimens with chemo-immunotherapy can be used. Rituximab plus bendamustine (BR) is an effective and manageable treatment option for patients affected by indolent non-Hodgkin lymphoma. The aim of this monocentric retrospective study was to analyze the effectiveness and safety of the use of BR regimen in MZL patients in first line in daily clinical practice. The treatment schedule was rituximab at the dose of 375 mg/m² on day 1 of each cycle and bendamustine at the dose of 90 mg/m² on day 2 and 3, every 28 days for a maximum of 6 cycles. We analyzed 65 MZL patients (28 extranodal [EMZL], 23 splenic [SMZL], and 14 nodal [NMZL]) who underwent BR regimen as first line treatment. The median time from diagnosis to therapy was 2.5 months. Final responses were: 38 complete response (CR, 58.5%), 20 partial response and 7 progressive disease, leading to an overall response rate (ORR) of 89.2%. With respect to the histology, the ORR was 89.3% for EMZL, 82.6% for SMZL and 100% for NMZL, respectively (difference not statistically significant). With a median follow-up time of 44.6 months (range, 3.3-175.0 months), 2 (one EMZL after 42 months and one SMZL after 10 months) of 38 (5.2%) CR patients had disease relapse, yielding an estimated disease free survival of 89.2% at 61.1 months. The estimated 6-year progression free survival was 71.8% with 15 relapsed/progressed patients showing lymphoma recurrence within 48 months from end of treatment. The most frequently reported adverse events (any grade) were neutropenia (N = 35, 53.8%), fatigue (N = 15, 23.0%), and nausea (N = 12, 18.4%). All toxicities quickly resolved and no treatment-related death occurred. The BR regimen is effective and feasible in MZL patients inducing prolonged disease control with manageable toxicities.

Bendamustine Conditioning Skews Murine Host DCs Toward Pre-cDC1s and Reduces GvHD Independently of Batf3

Graft-versus-host disease (GvHD) remains the second leading cause of death in allogeneic hematopoietic stem cell transplantation recipients, highlighting the need for improved preventative strategies. Our laboratory has previously demonstrated in an experimental bone marrow transplantation (BMT) model that bendamustine combined with total body irradiation (BEN+TBI) is a safer alternative to cyclophosphamide with TBI (CY+TBI). The biological mechanisms of action of BEN have not been fully elucidated and likely involve multiple cell populations. Host dendritic cells (DCs) can prime naïve donor T-cells immediately following transplantation, making host DCs critical for the initiation phase of GvHD. We hypothesized that BEN+TBI conditioning favorably alters host DC composition to reduce GvHD. We demonstrate that host DCs treated with BEN+TBI induce less allogeneic T-cell proliferation than those conditioned with CY+TBI. We further show that BEN+TBI conditioning results in greater total numbers of all host DC subsets but with a more favorable composition compared to CY+TBI with significantly larger proportions of type 1 conventional DCs (cDC1), a highly regulatory DC subset capable of suppressing GvHD. Our studies using recipient Batf3 KO mice indicate that CD8α+ cDC1s are largely dispensable for the reduced GvHD following BEN+TBI conditioning. We found a higher frequency of host pre-cDC1s with BEN+TBI conditioning in both wild-type (WT) and Batf3 KO mice, which was inversely associated with GvHD. Additionally, we observed that BEN treatment results in greater expression of Flt3 receptor (CD135) on host DCs compared to CY, potentially contributing to the skewing of host DCs toward cDC1s. Further, BEN+TBI conditioning results in host cDCs with greater expression of PIR-B, an inhibitory receptor capable of preventing lethal GvHD. We conclude that BEN+TBI is a safer alternative to CY+TBI, resulting in a greater frequency of host pre-cDC1s and limiting GvHD.

A Study of Safety and Efficacy of Nivolumab and Bendamustine (NB) in Patients With Relapsed/Refractory Hodgkin Lymphoma After Nivolumab Monotherapy Failure

This single-center prospective clinical trial evaluated the combination of nivolumab plus bendamustine (NB) as a salvage regimen in classical Hodgkin lymphoma patients after failure of nivolumab monotherapy. A total of 30 patients received nivolumab (3 mg/kg) on D1,14 and bendamustine (90 mg/m2) on D1, 2 of a 28-day cycle for up to 3 cycles. The ORR was 87% with 57% CR, 30% PR. With median follow-up of 25 months, the estimated 2-year OS was 96,7% (95% CI, 90.2%-100%), PFS was 23,3% (95% CI, 8.2%-38.4%) median PFS was 10.2 months (95% CI, 7.7-14.2 months) with median DOR 6.6 months (95% CI 3.9-11.6 months). Ten patients (33.3%) experienced grade 3 to 4 AE during therapy. Infections were most common AEs of the combined therapy. NB was a highly efficient salvage regimen in relapsed/refractory cHL with a manageable toxicity profile and modest potential for achievement of long-term remission. Registered at www.clinicaltrials.gov (#NCT0334365).

Progressive substitution of posttransplant cyclophosphamide with bendamustine: A phase I study in haploidentical bone marrow transplantation

We have initiated a single center phase I study in patients with hematologic malignancies progressively substituting day +4 posttransplant cyclophosphamide (PT‐CY) with bendamustine (PT‐BEN) following myeloablative conditioning (MAC) and T‐cell replete haploidentical bone marrow transplantation (haplo‐BMT). We report herein our interim analysis of our first three cohorts PT‐CY (mg/kg)/PT‐BEN (mg/m²): 40/20, 20/60, and 0/90. All patients have tolerated PT‐CY/BEN well with no dose limiting toxicities. Compared to contemporaneous controls undergoing haplo‐BMT with the same MAC regimens but only PT‐CY, we have observed earlier trilineage engraftment (P = .002 neutrophils, P = .014 platelets) and a lower incidence of cytomegalovirus reactivation (P = .016) in the PT‐CY/BEN cohorts. After substituting day +4 PT‐CY with PT‐BEN, the registered trial (www.clinicaltrials.gov;NCT02996773) is proceeding to replace day +3 PT‐CY with PT‐BEN with a view to identifying further evidence on the potential advantages of PT‐BEN.

Brentuximab vedotin followed by bendamustine supercharge for refractory or relapsed Hodgkin lymphoma

We evaluated the impact on progression-free survival (PFS) of achieving a deep metabolic response at 2-deoxy-2[¹⁸F] fluoro-d-glucose positron emission tomography (FDG-PET) in patients with refractory or relapsed (R/R) classic Hodgkin lymphoma (cHL) following a new salvage regimen named Bv+Bs (brentuximab vedotin + bendamustine supercharge), from 2013 to 2017. In this real-life study, 20 consecutive patients (aged <60 years) with R/R cHL after failure of ≥1 salvage treatments received Bv+Bs regimen consisting of 3-days outpatient IV infusions of 1.8 mg/kg of Bv on day 1 of each 3-week cycle combined in sequence to bendamustine on days 2 and 3 of the treatment cycle at a fixed dose of 120 mg/m² per day, for a total of 4 courses. A robust primary prophylaxis approach, including premedication, antimicrobials, stimulating factors, and cytomegalovirus monitoring, was systematically performed. The 20 patients (all evaluable) underwent 4 courses of Bv+Bs with a median dose intensity of 100% for both Bv and Bs. Ten patients (50%) experienced grade ≥3 treatment-related adverse events, without requiring hospitalization. At post-Bv+Bs reevaluation, 80% of patients had deep metabolic responses with Deauville 5-point scale scores ≤2. Thereafter, 14 patients (70%) received autologous hematopoietic stem cell transplantation (HSCT; peripheral blood stem cells previously harvested in 12 cases), and 4 patients (10%) received allogeneic HSCT. At a median follow-up of 27 months from Bv+Bs regimen initiation, the 2-year PFS of the entire population was 93.7% (95% confidence interval, 62.7% to 99.6%). Our data suggest that Bv+Bs regimen-driven strategy may be a promising salvage option to improve long-term control of high-risk Hodgkin lymphoma.

Lymphocyte-monocyte ratio (LMR) can predict bendamustine therapeutic efficacy in low-grade B-cell lymphoma

INTRODUCTION

Bendamustine has been reported to be effective against low-grade B-cell lymphoma. We examined the effect of bendamustine on the lymphocyte-monocyte ratio (LMR) in low-grade B-cell lymphoma patients.

METHODS

We retrospectively reviewed 127 cases of first line or relapse/refractory low-grade B-cell lymphoma in three individual institutions (Asahikawa Municipal Hospital, Aiiku Hospital, and Hakodate Municipal Hospital). Only patients who had received at least three courses of bendamustine therapy were selected; the LMR was evaluated at starting the initial course of bendamustine therapy. Time to next treatment (TTNT) was used to ascertain the efficacy of bendamustine therapy.

RESULTS

Follicular lymphoma (FL), at 68.5% (87/127), is the most common histological subtype of low-grade B-cell lymphoma. The receiver operating characteristic (ROC) curve for the LMR showed a cutoff value of 2.0, and 33 cases (26.0%) had an LMR ≤2.0. Cases with LMR ≤2.0 had a significantly earlier progression than those with LMR > 2.0, based on the TTNT (P = .0007). Additionally, LMR ≤2.0 indicates earlier progression in TTNT when comparing only FL and low-grade B-cell lymphoma cases without FL (P = .007, 0.002). For multivariate analysis, the factors associated with an LMR ≤2.0 (HR, 2.741; 95% CI, 1.4330-5.245; P = .002) were considered as early progression factors with regard to the TTNT.

CONCLUSION

Lymphocyte-monocyte ratio effectively predicts the efficacy of bendamustine therapy for low-grade B-cell lymphoma, particularly FL; its application may improve treatment strategies for this disease.

Increasing Diluent Volume Decreases Bendamustine-Induced Venous Irritation without Reducing the Therapeutic Efficacy

The intravenous injection of bendamustine often induces venous irritation, which reduces patients' QOL. We previously reported that the dilution of the final volume of bendamustine from 250 to 500 mL significantly decreased the incidence of venous irritation. However, the influence of this change on the therapeutic efficacy of bendamustine remains unclear. Therefore, the aim of this study was to evaluate the efficacy and safety profiles of bendamustine at different dilutions of the final volume, comparing with the correspondences of previous studies. Thirty-four patients, who received a total of 161 courses of bendamustine and rituximab chemotherapy, were included in this study. The overall response rate of this regimen was 94.1% in this study, which was comparable to that reported in the BRB study (94.2%, a phase II study of bendamustine plus rituximab therapy in Japanese patients). Additionally, the median progression-free survival was not inferior to that reported in the BRB study. Bendamustine-induced venous irritation was observed in 17.6% of the patients during the first treatment cycle administered at a final volume of 500 mL, and was found to be lower than that observed in the control, where bendamustine was administered at a final volume of 250 mL (85.7%). These results suggest that diluting bendamustine to 500 mL, but not to 250 mL, reduces the incidence of venous irritation without a negative impact on its therapeutic efficacy; thus, this simple strategy may be beneficial to ensure efficacy and safety in patients receiving regimens including bendamustine.

Autophagy Inhibition Potentiates the Anticancer Effects of a Bendamustine Derivative NL-101 in Acute T Lymphocytic Leukemia

Acute T lymphocytic leukemia (T-ALL) is an aggressive hematologic resulting from the malignant transformation of T-cell progenitors. Drug resistance and relapse are major difficulties in the treatment of T-ALL. Here, we report the antitumor potency of NL-101, a compound that combines the nitrogen mustard group of bendamustine with the hydroxamic acid group of vorinostat. We found NL-101 exhibited efficient antiproliferative activity in T-ALL cell lines (IC₅₀ 1.59–1.89 μM), accompanied by cell cycle arrest and apoptosis, as evidenced by the increased expression of Cyclin E1, CDK2, and CDK4 proteins and cleavage of PARP. In addition, this bendamustine-derived drug showed both a HDACi effect as demonstrated by histone hyperacetylation and p21 transcription and a DNA-damaging effect as shown by an increase in γ-H2AX. Intriguingly, we found that NL-101-induced autophagy in T-ALL cells through inhibiting Akt-mTOR signaling pathway, as indicated by an increase in LC3-I to LC3-II conversion and decrease of p62. Furthermore, inhibition of autophagy by 3-methyladenine increased apoptotic cell death by NL-101, suggesting a prosurvival role of autophagy. In summary, our finding provides rationale for investigation of NL-101 as a DNA/HDAC dual targeting drug in T-ALL, either as a single agent or in combination with autophagy inhibitors.

Phase II study of safety and efficacy of BEB (bendamustine, etoposide, and busulfan) conditioning regimen for autologous stem cell transplantation in non-Hodgkin lymphoma

Autologous stem cell transplant (ASCT) is an effective treatment for non-Hodgkin lymphoma (NHL). However, recent supply issues and toxicity of carmustine have necessitated a new conditioning regimen. We conducted a multicenter, phase II study of BEB (busulfan, etoposide, and bendamustine) conditioning regimen for ASCT in patients with NHL. Thirty-one patients were enrolled and underwent ASCT with the BEB conditioning regimen. The most common subtype was diffuse large B-cell lymphoma (n = 23, 74.2%). Nine patients (29.0%) had a history of relapse, and 18 patients (58.1%) received more than 2 lines of chemotherapy before ASCT. A median number of 6.05 × 10⁶/kg CD34 cells were infused, and all patients engrafted after a median period of 11 days. Thirteen patients (41.9%) experienced neutropenic fever, and 16 patients (51.6%) had grade 3 or 4 toxicities during ASCT. No one had a documented infection, veno-occlusive disease, or treatment-related death. Three-month complete remission rate was 81.8%. Median follow-up period of 15 months showed 6 patients (19.4%) relapsed or progressed and 3 patients died. The estimated 2-year progression-free survival and overall survival rate were 73.0% and 89.8%, respectively. Our results show that BEB conditioning regimens for ASCT are feasible with tolerable toxicity in patients with NHL.

Emerging treatment options for patients with p53-pathway-deficient CLL

Over the past 40 years, p53 has been the most widely studied protein in cancer biology. Originally thought to be an oncogene due to its stabilization in many cancers, it is now considered to be one of the most critical tumor suppressors in a cell's ability to combat neoplastic transformation. Due to its critical roles in apoptosis, cell-cycle arrest, and senescence, TP53 deletions and mutations are commonly observed and are often a portent of treatment failures and poor clinical outcomes. This is particularly true in chronic lymphocytic leukemia (CLL), as patients with p53 alterations have historically had dismal outcomes. As such, the tremendous efforts made to better understand the functions of p53 in CLL have contributed substantially to recent advances in treating patients with p53-pathway-deficient CLL.

Transcriptional Modulation by Idelalisib Synergizes with Bendamustine in Chronic Lymphocytic Leukemia

The phosphatidyl-inositol 3 kinase (PI3K) δ inhibitor, idelalisib (IDE), is a potent inhibitor of the B-cell receptor pathway and a novel and highly effective agent for the treatment of chronic lymphocytic leukemia (CLL). We evaluated the activities of IDE in comparison to bendamusine (BEN), a commonly used alkylating agent, in primary CLL cells ex vivo. In contrast to BEN, IDE was cytotoxic to cells from extensively-treated patients, including those with a deletion (del)17p. Cross-resistance was not observed between BEN and IDE, confirming their different modes of cytotoxicity. Marked synergy was seen between BEN and IDE, even in cases that were resistant to BEN or IDE individually, and those with deletion (del) 17p. CD40L/interleukin 4 (IL4) co-treatment mimicking the CLL microenvironment increased resistance to IDE, but synergy was retained. PI3Kδ-deficient murine splenic B cells were more resistant to IDE and showed reduced synergy with BEN, thus confirming the importance of functional PI3Kδ protein. Although IDE was observed to induce γH2AX, IDE did not enhance activation of the DNA damage response nor DNA repair activity. Interestingly, IDE decreased global RNA synthesis and was antagonistic with 5,6-Dichlorobenzimidazole 1-b-D-ribofuranoside (DRB), an inhibitor of transcription. These findings add to the increasingly complex cellular effects of IDE, and B cell receptor (BCR) inhibitors in general, in CLL.

Safety and efficacy of bendamustine in the conditioning regimen for autologous stem cell transplantation in patients with relapsed/refractory lymphoma

Background

Bendamustine is an attractive option for the management of both de novo and relapsed lymphomas. It is being increasingly used in the conditioning regimen for autologous stem cell transplantation (SCT) and can be an alternative to the traditionally-used carmustine. In this study, we aimed to determine the safety and efficacy of bendamustine in the conditioning regimen for autologous SCT in refractory/relapsed lymphomas.

Methods

We designed a descriptive study to evaluate bendamustine in combination with etoposide, cytarabine, and melphalan (BeEAM) in the conditioning regimen for autologous SCT.

Results

Fourteen patients (median age, 28 yr) with Hodgkin's lymphoma (HL) (N=8), non-Hodgkin's lymphomas (NHL) (N=5), or peripheral T-cell lymphoma, not otherwise specified (PTCL NOS) (N=1) were included in the study. A median number of 5.95×10⁶ CD34+ cells/kg were transfused. Median times to absolute neutrophil count and platelet engraftment were 17 days and 24 days, respectively. The 100-day transplantation mortality rate was 28% (4 patients). Eight patients (57.14%) had GII-III acute kidney injury, four patients (28.5%) had GIII-IV hyperbilirubinemia, and twelve patients (85%) had GII-III diarrhea. After 3 months, 37% (5 patients) and 21.4% (3 patients) demonstrated complete response and partial response, respectively. The median follow-up was 5.5 months (15 days–19 mo). At the final follow-up, 7 patients (50%) were alive and in CR.

Conclusion

Our study showed that bendamustine is a potentially toxic agent in the conditioning regimen for autologous SCT, resulting in significant liver, kidney, and gastrointestinal toxicity. Further studies are required to assess its safety and efficacy at reduced doses.