Efficacy of bendamustine in relapsed/refractory myeloma patients: results from the French compassionate use program

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.

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.

Bendamustine-Based Regimens as Salvage Therapy in Refractory/Relapsed Multiple Myeloma Patients: A Retrospective Real-Life Analysis by the Polish Myeloma Group

Multiple myeloma (MM) is an incurable disease and patients become refractory to the treatment in the course of the disease. Bendamustine-based regimens containing steroids and other agents are among the therapeutic options offered to MM patients. Here, we investigated the safety and the efficacy of bendamustine used in patients with refractory/relapsed MM (RRMM). The patients were treated with bendamustine and steroids (n = 52) or bendamustine, steroids and immunomodulatory agents or proteasome inhibitors (n = 53). Response rates, progression-free survival (PFS), overall survival (OS) and frequency of adverse events were compared between both study groups. Most efficacy measurements were better in patients treated with three-drug regimens: overall response rate (55% versus 37%, p = 0.062), median PFS (9 months versus 4 months, p < 0.001), median OS survival (18 months versus 12 months, p = 0.679). The benefit from combining bendamustine and steroids with an additional agent was found in subgroups previously treated with both lenalidmide and bortezomib, with stem cell transplant and with more than two previous therapy lines. Toxicity was similar in both study groups and bendamustine-based therapies were generally well-tolerated. Our study suggests that bendamustine may be an effective treatment for patients with RRMM. Three-drug regimens containing bendamustine, steroids and novel agents produced better outcomes and had acceptable toxicity. The efficacy of bendamustine combined with steroids was limited.

Aggressive T-cell lymphomas: 2021 Updates on diagnosis, risk stratification and management

INTRODUCTION

Aggressive T-cell lymphomas continue to have a poor prognosis. There are over 27 different subtypes of peripheral T-cell lymphoma (PTCL), and we are now beginning to understand the differences between the various subtypes beyond histologic variations.

MOLECULAR PATHOGENESIS OF VARIOUS SUBTYPES OF PTCL

Gene expression profiling (GEP) can help in diagnosis and prognostication of various subtypes including PTCL-nos and anaplastic large cell lymphoma (ALCL). In addition, mutational analysis is now being incorporated in clinical trials of novel agents to evaluate various biomarkers of response to allow better therapeutic choices for patients.

TARGETED THERAPIES

There are many targeted agents currently in various stages of clinical trials for PTCL that take advantage of the differential expression of specific proteins or receptors in PTCL tumors. This includes the CD30 directed antibody drug conjugate brentuximab vedotin. Other notable targets are CD25, CCR4, inhibition of PI3kinase - m TOR and JAK/STAT pathways. The ALK inhibitors are promising for ALK expressing tumors.

IMMUNOTHERAPIES

Allogeneic stem cell transplant continues to be the curative therapy for most aggressive subtypes of PTCL. The use of checkpoint inhibitors in the treatment of PTCL is still controversial. The most promising results have been seen in cases of extranodal natural killer cell/T-cell (ENK/T) lymphomas and cutaneous T-cell lymphomas (CTCL). Bispecific antibody based treatments as well as CAR-T cell based therapies are in clinical trials.

Allogeneic stem cell transplantation for peripheral T cell lymphomas: a retrospective study in 285 patients from the Société Francophone de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC)

BACKGROUND

Peripheral T cell lymphomas form a heterogeneous group with a usually dismal prognostic. The place of allogeneic stem cell transplantation to treat PTCL is debated.

METHODS

We retrospectively analyzed the overall survival (OS), event-free survival (EFS), relapse, and transplant-related mortality (TRM) and associated variables in 285 adults with non-primary cutaneous PTCL (PCTL-NOS (39%), angioimmunoblastic T cell lymphomas (29%), anaplastic T cell lymphomas (15%), and other subtypes (17%)), who received alloSCT in 34 centers between 2006 and 2014.

RESULTS

AlloSCT was given as part of front-line therapy (n = 138) to 93 patients in first complete response (CR) and 45 in first partial response (PR), and of salvage therapy (n = 147) to 116 patients for second or more CR/PR and 31 for progressive disease. Reduced-intensity conditioning (RIC) was given to 172 patients (62%), while 107 (38%) received myeloablative conditioning (MAC). The median follow-up was 72.4 months. The 2- and 4-year OS were 65% and 59%, respectively, and the cumulative incidence of relapse was 18% after 1 year and 19% after 2 years. TRM was 21% at 1 year, 24% after 2 years, and 28% after 4 years. In multivariate analysis, grade III-IV acute GvHD (HR = 2.57, 95% CI 1.53-4.31; p = 0.00036), low Karnofsky score < 80% (HR = 5.14, 95% CI 2.02-13.06; p = 0.00058), and progressive disease status before transplant (HR = 2.21, 95% CI 1.25-3.89; p = 0.0062) were significantly associated with a reduced OS.

CONCLUSIONS

The data demonstrate in the largest retrospective cohort of non-cutaneous PTCL so far reported that alloSCT after RIC or MAC is an effective strategy, even in chemoresistant patients.

Efficacy and Safety of Melphalan, Cyclophosphamide and Dexamethasone (MCD) as a Salvage Treatment for Patients with Relapsed/Refractory Multiple Myeloma

This study investigated the efficacy and safety of melphalan, cyclophosphamide, and dexamethasone (MCD) as a salvage regimen for heavily treated relapsed or refractory multiple myeloma patients. We retrospectively analyzed a total of 27 patients who received the MCD regimen between April 2011 and November 2013. The MCD regimen consisted of oral melphalan 6.75 mg/m² on days 1–4, once-weekly dose of oral cyclophosphamide 300 mg/m² and dexamethasone 20 mg/m² on days 1–4 and days 15–18. Each cycle was repeated every 28 days. The median age of the patients was 66 years and the MCD regimen was initiated at a median 37.7 months from diagnosis. Patients received a median of five regimens including autologous stem cell transplantation. The overall response rate was 25.9% (very good partial response 3.7%, partial response 22.2%) and 8 (29.6%) patients achieved a minor response. Median progression-free survival was 5.6 months (95% confidence interval [CI], 4.2–8.5) ; overall survival 11.7 months (95% CI, 5.4–16.6). Grade 3 or 4 neutropenia and thrombocytopenia were observed in 51.8% and 33.3%, respectively. Although the overall response rate is relatively low, the MCD regimen may have a role as a bridge to a novel regimen in heavily pretreated patients with MM.

AL amyloidosis: advances in diagnostics and treatment

AL amyloidosis (light chain; previously also called primary amyloidosis) is a systemic disease characterized by an amyloid deposition process affecting many organs, and which still has unsatisfactory survival of patients. The monoclonal light chains kappa (κ) or lambda (λ) or their fragments form the fibrils that deposit and accumulate in different tissues. Renal involvement is very frequent in AL amyloidosis and can lead to the development of nephrotic syndrome followed by renal failure in some cases. AL amyloidosis ultimately leads to destruction of tissues and progressive disease. With recent advances in the treatment, the importance of an early diagnosis of amyloidosis and correct assessment of its type is high. Histologic confirmation is based on Congo red detection of amyloid deposits in tissues but AL amyloidosis must also be distinguished from other systemic forms of amyloidoses with renal involvement, such as AA amyloidosis, amyloidosis with heavy chain deposition, fibrinogen Aα or ALECT2 (leukocyte chemotactic factor 2) deposition. Immunofluorescence (IF) plays a key role here. IF on formalin-fixed paraffin-embedded tissue after protease digestion, immunohistochemistry or laser microdissection with mass spectrometry should complete the diagnosis in unclear cases. Standard treatment with melphalan and prednisolone or with cyclophosphamide and dexamethasone has been replaced with newer drugs used for the treatment of multiple myeloma—bortezomib, carfilzomib and ixazomib or thalidomide, lenalidomide and pomalidomide. High-dose melphalan supported by autologous stem cell transplantation remains the therapeutic option for patients with low-risk status. These new treatment options prolong survival from months to years and improve the prognosis in a majority of patients.

A look at treatment strategies for relapsed multiple myeloma

INTRODUCTION

Multiple myeloma treatment considerably improved during the past decade, thanks to novel effective drugs, a better understanding of myeloma biology and clonal heterogeneity, and an improved management of toxicities. The choice of regimen at relapse is usually based on prior response, toxicities, age and comorbidities of relapsed patients. Areas covered: A review was performed of the most recent and effective therapeutic strategies for the relapsed myeloma setting, by documenting the latest clinical evidence from phase II and III clinical trials. Of note, new drugs, such as carfilzomib, ixazomib, pomalidomide, daratumumab and elotuzumab, alone or in combinations in doublet or triplet regimens, have greatly increased the treatment armamentarium against myeloma. Expert commentary: Impressive results have been obtained with new drugs in relapsed patients. Besides number of prior therapies and previous response, other factors play a crucial role in the selection of therapy. Re-challenge with previous drugs can be adopted if previous responses lasted at least 6 months and therapy had induced low toxicity. Patients' risk status can further help to appropriately select therapy at relapse, and clinical trials will allow physicians to use newer targeted therapies and immune-therapies, thus delaying palliative approaches to later relapse stages.

Clinical Outcomes Related to the Use of Bendamustine Therapy for Multiple Myeloma Patients Relapsed/Refractory to Immunomodulatory Drugs and Proteasome Inhibitors

Objective:

Multiple myeloma patients who are relapsed or refractory to both proteasome inhibitors (PIs) and immunomodulatory drugs (IMiDs) have been reported to have poor outcomes. Bendamustine has been reported to have an antitumor effect in newly diagnosed as well as relapsed/refractory multiple myeloma (RRMM). The aim of this retrospective study was to evaluate the efficacy of bendamustine therapy in heavily pretreated MM patients who were refractory to PIs and IMiDs.

Materials and Methods:

Nineteen RRMM patients treated either with bendamustine and steroids (n=13) or a combination of bendamustine with novel drugs (n=6) were included. The median number of previous treatment lines was 5 (minimum-maximum: 3-8) and median time from diagnosis was 6 years (minimum-maximum: 1-16). All of the patients were resistant to at least one of the IMiDs and one of the PIs. Bendamustine was given at doses ranging from 90 mg/m² to 120 mg/m² on days 1 and 2 of 28-day cycles.

Results:

A median of 2 (minimum-maximum: 1-8) treatment cycles was administered per patient. The toxicity of bendamustine was mild and mostly of hematological origin. No complete remission was achieved. There was partial remission and stable disease in 21% and 11% of the patients, respectively. Sixty-eight percent of patients had progressive disease. The median progression-free survival and overall survival was 2 and 4 months, respectively.

Conclusion:

Bendamustine therapy was well tolerated but showed limited anti-myeloma activity in heavily pretreated patients who were refractory to IMiDs and PIs.

Bendamustine hydrochloride in patients with B-cell malignancies who have comorbidities - is there an optimal dose?

INTRODUCTION

The majority of patients with non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL) present with comorbidities. Many of them are poor candidates for intensive chemo-immunotherapy regimens, such as FCR (fludarabine, cyclophosphamide, rituximab). Still, most clinical trials aim to enroll 'fit' patients, who poorly represent the community oncology population. Areas covered: In the past decade, bendamustine hydrochloride, a cytotoxic agent with structural similarities to both alkylating agents and purine analogs, has received widespread use in therapy of NHL and CLL, and has demonstrated a relatively favorable toxicity profile. However, bendamustine has not been well studied in patients with hematologic malignancies who have comorbidities. Here we review the clinical data on use of bendamustine in older and unfit patients with NHL and CLL, and analyze whether there is an optimal dose of bendamustine in patients who have significant comorbidities, including renal dysfunction. Expert commentary: Reduced intensity regimens of bendamustine are effective in CLL patients with comorbidities and renal dysfunction. Even with the introduction of targeted therapies, bendamustine will likely continue to be an important therapeutic option in patients with comorbidities because of its tolerability, efficacy and cost.

Retreatment with Bendamustine-Bortezomib-Dexamethasone in a Patient with Relapsed/Refractory Multiple Myeloma

The clinical management of relapsed/refractory multiple myeloma and the correct choice of the most suitable therapy in heavily pretreated and fragile patients are tough clinical issues for clinicians. In advanced phases of disease, the choice of available therapies becomes very poor, and the retreatment with previously adopted and effective therapy, although unpredictable, could be an effective option. In this report, we describe the clinical history of a patient, previously treated with 9 lines of therapy, refractory to bortezomib and IMIDs, for whom the retreatment with bendamustine resulted in a stable disease with good quality of life.

Bendamustine, etoposide and dexamethasone to mobilize peripheral blood hematopoietic stem cells for autologous transplantation in patients with multiple myeloma

Chemotherapeutic agents without cross-resistance to prior therapies may enhance PBSC collection and improve patient outcomes by exacting a more potent direct antitumor effect before autologous stem cell transplant. Bendamustine has broad clinical activity in transplantable lymphoid malignancies, but concern remains over the potential adverse impact of this combined alkylator-nucleoside analog on stem cell mobilization. We performed a prospective, nonrandomized phase II study including 34 patients with multiple myeloma (MM) (n=34; International Staging System (ISS) stages I (35%), II (29%) and III (24%); not scored (13%)) to evaluate bendamustine's efficacy and safety as a stem cell mobilizing agent. Patients received bendamustine (120 mg/m2 IV days 1, 2), etoposide (200 mg/m2 IV days 1-3) and dexamethasone (40 mg PO days 1- 4) (bendamustine, etoposide and dexamethasone (BED)) followed by filgrastim (10 μg/kg/day SC; through collection). All patients (100%) successfully yielded stem cells (median of 21.60 × 106/kg of body weight; range 9.24-55.5 × 106/kg), and 88% required a single apheresis. Six nonhematologic serious adverse events were observed in 6 patients including: neutropenic fever (1, grade 3), bone pain (1, grade 3) and renal insufficiency (1, grade 1). In conclusion, BED safely and effectively mobilizes hematopoietic stem cells.

Bendamustine in heavily pre-treated multiple myeloma patients: Results of a retrospective analysis from the Korean Multiple Myeloma Working Party

Background

Bendamustine may be a potential treatment option for patients with myeloma, but little is known about the utility of bendamustine as a salvage treatment, especially in Asian patients.

Methods

We performed a multicenter retrospective study of patients with relapsed or refractory myeloma who received bendamustine and prednisone.

Results

The records of 65 heavily pre-treated patients, who had undergone bortezomib and lenalidomide treatment (median number of previous treatments: 5), were analyzed. The median time from diagnosis to bendamustine treatment was 3.8 years, and the median patient age was 63 years (range, 38‒77 yr). The responses to the last treatment before bendamustine were refractory disease (N=52, 80%) or disease progression from partial response (N=13, 20%). Twenty-three patients responded to the treatment, with an overall response rate of 35% (23/65), and the median number of bendamustine treatment cycles was two (range, 1‒5 cycles). The median overall survival after bendamustine treatment was 5.5 months and the overall survival rate in responders to bendamustine was significantly better than that in non-responders (P=0.036).

Conclusion

Bendamustine may be a potential salvage treatment to extend survival in a select group of heavily pre-treated patients with relapsed or refractory myeloma.

Bendamustine, lenalidomide, and dexamethasone (BRD) is highly effective with durable responses in relapsed multiple myeloma

Bendamustine is a multifunctional alkylating agent with single agent activity in myeloma. We designed the current phase 1/2 trial to determine the maximum tolerated doses (MTD) of bendamustine that can be safely combined with lenalidomide and dexamethasone and to assess the safety and efficacy of the combination. Patients with relapsed MM following at least 1 prior therapy, but no more than four lines of prior therapy and with measurable disease were enrolled. Bendamustine 75 mg/m(2) given on days 1 and 2, lenalidomide 25 mg given days 1-21 and dexamethasone 40 mg on days 1, 8, 15, and 22, was the recommended Phase 2 dose. Seventy-one patients were accrued: 21 on Phase 1 and 50 on Phase 2. The median age was 62.3 years; patients had a median of three prior lines of therapy (range 1-4), with over 70% of the patients having received prior lenalidomide, bortezomib, and/or peripheral blood stem cell transplant. Thirty-four of 70 (49%) patients had a confirmed partial response or better, including 20 patients (29%) with a very good partial response or better. An additional 4 patients had a minor response, translating to an overall 55% clinical benefit rate. Grade 3 or higher toxicity was seen in 96% of patients, with ≥grade 3 hematologic in 94% and nonhematologic in 50%. The median progression free survival was 11.8 months and the median duration of response was 23 months. The combination of bendamustine, lenalidomide, and dexamethasone is very effective in relapsed multiple myeloma with high response rates and durable responses

Optimal use of bendamustine in hematologic disorders: Treatment recommendations from an international consensus panel - an update

Bendamustine has achieved widespread international regulatory approval and is a standard agent for the treatment for chronic lymphocytic leukemia (CLL), indolent non-Hodgkin lymphoma and multiple myeloma. Since approval, the number of indications for bendamustine has expanded to include aggressive non-Hodgkin lymphoma and Hodgkin lymphoma and novel targeted therapies, based on new bendamustine regimens/combinations, are being developed against CLL and lymphomas. In 2010, an international panel of bendamustine experts met and published a set of recommendations on the safe and effective use of bendamustine in patients suffering from hematologic disorders. In 2014, this panel met again to update these recommendations since the clarification of issues including optimal dosing and management of bendamustine-related toxicities. The aim of this report is to communicate the latest consensus on the use of bendamustine, permitting the expansion of its safe and effective administration, particularly in new combination therapies.

Recommendations on the clinical use of bendamustine in lymphoproliferative syndromes and multiple myeloma

Bendamustine is an increasingly used hybrid alkylating agent that is active in lymphoid neoplasias via a novel mechanism of action. There are some pending questions about its use in clinical practice because of its developmental features. A consensus panel of several leading Spanish hematologists with broad experience in the clinical use of bendamustine has established recommendations for the management and treatment of hematological patients with bendamustine based on available clinical data and the experience of the participants. These recommendations address the dose and treatment regimen for different clinical indications, the management of toxicity, and support therapy. This article contains the conclusions of this consensus panel, which are intended to serve as guidelines for the use of bendamustine.

Bendamustine in multiple myeloma

The advent of high-dose melphalan with autologous stem-cell transplantation (ASCT), the availability of novel agents such as thalidomide, lenalidomide (immunomodulatory drugs or IMiDs) and bortezomib (proteasome inhibitor) and improvements in supportive care have allowed to increase overall survival in multiple myeloma (MM) patients; nevertheless, MM remains an incurable pathology. For this reason, newer agents are required for continued disease control. Bendamustine is an old drug rediscovered in the last decade. In fact, its unique mechanism of action with structural similarities to both alkylating agents and antimetabolities, but which is not cross-resistant to alkylating agents, has reawakened interest in the use of this drug in the treatment of MM. Studies have proven the safety and efficacy of bendamustine administered alone or in combination with new drugs in both upfront and relapse/refractory settings of MM patients, including those with renal impairment. Moreover, bendamustine has been successfully used as conditioning for autologous stem-cell transplantation. Finally, the use of bendamustine does not compromise peripheral blood stem-cell collection. This drug is generally well tolerated, with the majority of adverse events being due to myelosuppression. Non-haematological adverse events are infrequent and usually mild.

Bendamustine, thalidomide and dexamethasone combination therapy for relapsed/refractory myeloma patients: results of the MUKone randomized dose selection trial

There is a significant unmet need in effective therapy for relapsed myeloma patients once they become refractory to bortezomib and lenalidomide. While data from the front line setting suggest bendamustine is superior to melphalan, there is no information defining optimal bendamustine dose in multiply-treated patients. We report a multi-centre randomized two-stage phase 2 trial simultaneously assessing deliverability and activity of two doses of bendamustine (60 mg/m2 vs. 100 mg/m2) days 1 and 8, thalidomide (100 mg) days 1-21 and low dose dexamethasone (20 mg) days 1, 8, 15 and 22 of a 28-d cycle. Ninety-four relapsing patients were treated on trial, with a median three prior treatment lines. A pre-planned interim deliverability and activity assessment led to closure of the 100 mg/m2 arm due to excess cytopenias, and led to amendment of entry criteria for cytopenias. Non-haematological toxicities including thromboembolism and neurotoxicity were infrequent. In the 60 mg/m2 arm, treatment was deliverable in 61.1% subjects and the partial response rate was 46.3% in the study eligible population, with 7.5 months progression-free survival. This study demonstrates bendamustine at 60 mg/m2 twice per month with thalidomide and dexamethasone is deliverable for repeated cycles in heavily pre-treated myeloma patients and has substantial clinical activity.

Efficacy and tolerability of bendamustine, bortezomib and dexamethasone in patients with relapsed-refractory multiple myeloma: a phase II study

Bendamustine demonstrated synergistic efficacy with bortezomib against multiple myeloma (MM) cells in vitro and seems an effective treatment for relapsed-refractory MM (rrMM). This phase II study evaluated bendamustine plus bortezomib and dexamethasone (BVD) administered over six 28-day cycles and then every 56 days for six further cycles in patients with rrMM treated with ⩽4 prior therapies and not refractory to bortezomib. The primary study end point was the overall response rate after four cycles. In total, 75 patients were enrolled, of median age 68 years. All patients had received targeted agents, 83% had 1–2 prior therapies and 33% were refractory to the last treatment. The response rate⩾partial response (PR) was 71.5% (16% complete response, 18.5% very good PR, 37% partial remission). At 12 months of follow-up, median time-to-progression (TTP) was 16.5 months and 1-year overall survival was 78%. According to Cox regression analysis, only prior therapy with bortezomib plus lenalidomide significantly reduced TTP (9 vs 17 months; hazard ratio=4.5; P=0.005). The main severe side effects were thrombocytopenia (30.5%), neutropenia (18.5%), infections (12%), neuropathy (8%) and gastrointestinal and cardiovascular events (both 6.5%). The BVD regimen is feasible, effective and well-tolerated in difficult-to-treat patients with rrMM.

An old drug with a new future: bendamustine in multiple myeloma

INTRODUCTION

Bendamustine is a unique bifunctional alkylating agent with promising activity in multiple myeloma (MM). It is currently licensed in Europe for use as frontline treatment with prednisolone for patients with MM who are unsuitable for transplantation and who are contraindicated for thalidomide and bortezomib therapy.

AREAS COVERED

Studies evaluating the safety and efficacy of bendamustine administered alone or in combination in both the upfront and relapse settings of MM patients, including those with renal insufficiency, were reviewed. The use of bendamustine as conditioning for autologous stem-cell transplantation and the possibility of stem-cell mobilization after bendamustine therapy are discussed.

EXPERT OPINION

Bendamustine seems to be efficacious either in monotherapy or in combination with other drugs in previously treated or untreated patients. This is due to its unique mechanism of action including its ability to activate apoptosis and inhibit mitotic checkpoints, making it potentially more effective than other alkylating agents. Moreover, it has an acceptable toxicity profile and is suitable for patients with renal impairment. Finally, this drug does not seem to compromise the possibility of achieving a stem-cell mobilization. Nonetheless, data from Phase III studies demonstrating its effectiveness in terms of overall survival are not yet available.

A phase 1 study of bendamustine and melphalan conditioning for autologous stem cell transplantation in multiple myeloma

Bendamustine has efficacy in multiple myeloma with a toxicity profile limited to myelosuppression. We hypothesized that adding bendamustine to autologous stem cell transplant conditioning in myeloma would enhance response without significant additional toxicity. We conducted a phase 1 trial adding escalating doses of bendamustine to the current standard conditioning of melphalan 200 mg/m(2). Twenty-five subjects were enrolled into 6 cohorts. A maximum tolerated dose was not encountered and the highest dose level cohort of bendamustine 225 mg/m(2) + melphalan 200 mg/m(2) was expanded to further evaluate safety. Overall, there was no transplant related mortality and only one grade 4 dose-limiting toxicity was observed. Median number of days to neutrophil and platelet engraftment were 11 (range, 9 to 14) and 13 (range, 10 to 21), respectively. Disease responses at day +100 posttransplantation were progression in 5 (21%), partial response in 1 (4%), very good partial response in 7 (33%), complete response in 1 (4%), and stringent complete response in 9 (38%). Six patients (24%) with pre-existing high-risk disease died from progressive myeloma during study follow-up, all at or beyond 100 days after autologous stem cell transplant. Bendamustine up to a dose of 225 mg/m(2) added to autologous stem cell transplantation conditioning with high-dose melphalan in patients with multiple myeloma did not exacerbate expected toxicities.

Bendamustine overcomes resistance to melphalan in myeloma cell lines by inducing cell death through mitotic catastrophe

Melphalan has been a mainstay of multiple myeloma (MM) therapy for many years. However, following treatment with this alkylator, malignant plasma cells usually escape both apoptosis and cell cycle control, and acquire drug-resistance resulting in tumor progression. Bendamustine is being used in MM patients refractory to conventional DNA-damaging agents, although the mechanisms driving this lack of cross-resistance are still undefined. Here, we investigated the molecular pathway of bendamustine-induced cell death in melphalan-sensitive and melphalan-resistant MM cell lines. Bendamustine affected cell survival resulting in secondary necrosis, and prompted cell death primarily through caspase-2 activation. Also, bendamustine blocked the cell cycle in the G2/M phase and induced micronucleation, erratic chromosome spreading and mitotic spindle perturbations in melphalan-resistant MM cells. In these cells, both Aurora kinase A (AURKA) and Polo-like kinase-1 (PLK-1), key components of the spindle-assembly checkpoint, were down-regulated following incubation with bendamustine, whereas levels of Cyclin B1 increased as a consequence of the prolonged mitotic arrest induced by the drug. These findings indicate that, at least in vitro, bendamustine drives cell death by promoting mitotic catastrophe in melphalan-resistant MM cells. Hence, activation of this alternative pathway of cell death may be a novel approach to the treatment of apoptosis-resistant myelomas.

United Kingdom Myeloma Forum (UKMF) position statement on the use of bendamustine in myeloma

Bendamustine is a unique bifunctional alkylating agent with promising activity in myeloma. Despite the increasing number of studies demonstrating its efficacy in both the upfront and relapse settings, including patients with renal insufficiency, the optimal use of bendamustine, in terms of dosage, schedule and combination with other agents, has yet to be defined. It is currently licensed for use as frontline treatment with prednisolone for patients with myeloma who are unsuitable for transplantation and who are contraindicated for thalidomide and bortezomib. Studies in relapsed/refractory patients are currently ongoing with other combinations. Given the increasing data to date, the UK Myeloma Forum believes that bendamustine with steroids alone or in combination with a novel agent could be considered for patients with multiply relapsed myeloma. This document provides guidance for the use of bendamustine for patients with myeloma until the results of definitive studies are available.

Multiple myeloma: improved outcomes with new therapeutic approaches

PURPOSE OF REVIEW

Nearly all patients with multiple myeloma will eventually relapse; and, thus, it is critical to identify new treatments that increase therapeutic options for these patients. This review highlights the newest approaches with already approved drugs for treating this common B-cell malignancy.

RECENT FINDINGS

Most patients with multiple myeloma in both the frontline and relapsed/refractory settings are now treated with a combination of dexamethasone with the proteasome inhibitor bortezomib and/or an immunomodulatory agent thalidomide or lenalidomide. However, alkylating agents including melphalan, cyclophosphamide and most recently bendamustine as well as anthracyclines, especially the pegylated liposomal doxorubicin, have shown high response rates and prolonged remissions when combined with these agents. There are emerging data showing the importance of maintenance therapy especially with lenalidomide. Because of the marked improvement in survival of multiple myeloma during the past decade, there has been a renewed emphasis on developing therapies that are not only effective but also well tolerated. Alternative dosing, scheduling and routes of administration of already approved drugs have proven effective in accomplishing these goals.

SUMMARY

The availability of drugs with different mechanisms that produce anti-multiple myeloma effects and also show synergistic effects has paved the way for more effective and safer combinations and led to multiple myeloma patients living longer with improved quality of lives.

Results From a Prospective, Open-Label, Phase II Trial of Bendamustine in Refractory or Relapsed T-Cell Lymphomas: The BENTLY Trial

Purpose

To determine the efficacy and safety of bendamustine as a single agent in refractory or relapsed T-cell lymphomas.

Patients and Methods

Patients with histologically confirmed peripheral T-cell lymphoma (PTCL) or cutaneous T-cell lymphoma who progressed after one or more lines of prior chemotherapy received bendamustine at 120 mg/m2 per day on days 1 through 2 every 3 weeks for six cycles. The primary end point was overall response rate (ORR). Secondary end points were duration of response (DOR), progression-free survival (PFS), and overall survival (OS).

Results

Of the 60 patients included, 27 (45%) were refractory to their last prior chemotherapy, and the median duration of the best previous response was 6.6 months. Histology was predominantly angioimmunoblastic lymphadenopathy and PTCL not otherwise specified. The disease was disseminated in the majority of patients (87%). The median number of previous lines of chemotherapy was one (range, one to three). Twenty patients (33%) received fewer than three cycles of bendamustine, mostly because of disease progression. In the intent-to-treat population, the ORR was 50%, including complete response in 17 patients (28%) and partial response in 13 patients (22%). Bendamustine showed consistent efficacy independent of major disease characteristics. The median values for DoR, PFS, and OS were 3.5, 3.6, and 6.2 months, respectively. The most frequent grade 3 to 4 adverse events were neutropenia (30%), thrombocytopenia (24%), and infections (20%).

Conclusion

Bendamustine showed an encouraging high response rate across the two major PTCL subtypes, independent of age and prior treatment, with acceptable toxicity in refractory or relapsed T-cell lymphoma.