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

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.

Management of Relapsed-Refractory Multiple Myeloma in the Era of Advanced Therapies: Evidence-Based Recommendations for Routine Clinical Practice

Multiple myeloma (MM) is the second most common hematologic malignancy in adults worldwide. Over the past few years, major therapeutic advances have improved progression-free and overall survival, as well as quality of life. Despite this recent progress, MM remains incurable in the vast majority of cases. Patients eventually relapse and become refractory to multiple drug classes, making long-term management challenging. In this review, we will focus on the treatment paradigm of relapsed/refractory MM (RRMM) in the era of advanced therapies emphasizing the available novel modalities that have recently been incorporated into routine practice, such as chimeric antigen receptor T-cell therapy, bispecific antibodies, and other promising approaches. We will also discuss major factors that influence the selection of appropriate drug combinations or cellular therapies, such as relapse characteristics, and other disease and patient related parameters. Our goal is to provide insight into the currently available and experimental therapies for RRMM in an effort to guide the therapeutic decision-making process.

Relapsed/Refractory Multiple Myeloma: A Review of Available Therapies and Clinical Scenarios Encountered in Myeloma Relapse

Multiple myeloma remains an incurable disease with the usual disease course requiring induction therapy, autologous stem cell transplantation for eligible patients, and long-term maintenance. Risk stratification tools and cytogenetic alterations help inform individualized therapeutic choices for patients in hopes of achieving long-term remissions with preserved quality of life. Unfortunately, relapses occur at different stages of the course of the disease owing to the biological heterogeneity of the disease. Addressing relapse can be complex and challenging as there are both therapy- and patient-related factors to consider. In this broad scoping review of available therapies in relapsed/refractory multiple myeloma (RRMM), we cover the pharmacologic mechanisms underlying active therapies such as immunomodulatory agents (IMiDs), proteasome inhibitors (PIs), monoclonal antibodies (mAbs), traditional chemotherapy, and Venetoclax. We then review the clinical data supporting the use of these therapies, organized based on drug resistance/refractoriness, and the role of autologous stem cell transplant (ASCT). Approaches to special situations during relapse such as renal impairment and extramedullary disease are also covered. Lastly, we look towards the future by briefly reviewing the clinical data supporting the use of chimeric antigen receptor (CAR-T) therapy, bispecific T cell engagers (BITE), and Cereblon E3 Ligase Modulators (CELMoDs).

How I Treat Relapsed Multiple Myeloma

Despite recent advances multiple myeloma remains an incurable disease for most of the patients and initial remission will be followed by relapses requiring therapy. For many, there will be several remissions and relapses until resistance develops to all available therapies. With the introduction of several new agents, myeloma treatment has changed drastically and there are new options for the management of relapsed or refractory disease, including new drug classes with distinct mechanisms of action and cellular therapies. However, resistance to major drug classes used in first line remain the most critical factor for the choice of treatment at relapse. Continuous lenalidomide-based therapy is used extensively at first line and resistance to lenalidomide has become the key factor for the choice of salvage therapy. Daratumumab is increasingly used in first line and soon patients that relapse while on daratumumab will become a common challenge. Three-drug regimens are standard approach to manage relapsed disease. Adding drugs with new mechanisms of activity can improves outcomes and overcomes class resistance but, until now, while the biology is important, can offer only limited guidance for the choice of therapy.

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.

Optimising cardiovascular care of patients with multiple myeloma

Multiple myeloma (MM) is the third most common haematological malignancy, with increasing prevalence over recent years. Advances in therapy have improved survival, changing the clinical course of MM into a chronic condition and meaning that management of comorbidities is fundamental to improve clinical outcomes. Cardiovascular (CV) events affect up to 7.5% of individuals with MM, due to a combination of patient, disease and treatment-related factors and adversely impact survival. MM typically affects older people, many with pre-existing CV risk factors or established CV disease, and the disease itself can cause renal impairment, anaemia and hyperviscosity, which exacerabate these further. Up to 15% of patients with MM develop systemic amyloidosis, with prognosis determined by the extent of cardiac involvement. Management of MM generally involves administration of multiple treatment lines over several years as disease progresses, with many drug classes associated with adverse CV effects including high rates of venous and arterial thrombosis alongside heart failure. Recommendations for holistic management of patients with MM now include routine baseline risk stratification including ECG and echocardiography and administration of thromboprophylaxis drugs for patients treated with immunomodulatory drugs. Close surveillance of high-risk patients with collaboration between haematology and cardiology is required, with prompt investigation in the event of CV symptoms, in order to identify and treat complications early. Decisions regarding discontinuation of cardiotoxic therapies should be made in a multidisciplinary setting, taking into account the severity of the complication, prognosis, expected benefits and the availability of effective alternatives.

Carfilzomib, bendamustine, and dexamethasone in patients with advanced multiple myeloma: The EMN09 phase 1/2 study of the European Myeloma Network

BACKGROUND

Combined therapy with carfilzomib, bendamustine, and dexamethasone was evaluated in this multicenter phase 1/2 trial conducted within the European Myeloma Network (EMN09 trial).

METHODS

Sixty-three patients with relapsed/refractory multiple myeloma who had received ≥2 lines of prior therapy were included. The phase 1 portion of the study determined the maximum tolerated dose of carfilzomib with bendamustine set at 70 mg/m² on days 1 and 8. After 8 cycles, responding patients received maintenance therapy with carfilzomib and dexamethasone until progression.

RESULTS

On the basis of the phase 1 results, the recommended phase 2 dose for carfilzomib was 27 mg/m² twice weekly in weeks 1, 2, and 3. Fifty-two percent of patients achieved a partial response or better, and 32% reached a very good partial response or better. The clinical benefit rate was 93%. After a median follow-up of 21.9 months, the median progression-free survival was 11.6 months, and the median overall survival was 30.4 months. The reported grade ≥3 hematologic adverse events (AEs) were lymphopenia (29%), neutropenia (25%), and thrombocytopenia (22%). The main nonhematologic grade ≥3 AEs were pneumonia, thromboembolic events (10%), cardiac AEs (8%), and hypertension (2%).

CONCLUSIONS

In heavily pretreated patients who have relapsed/refractory multiple myeloma, combined carfilzomib, bendamustine, and dexamethasone is an effective treatment option administered in the outpatient setting. Infection prophylaxis and attention to patients with cardiovascular predisposition are required.

Belantamab Mafodotin to Treat Multiple Myeloma: A Comprehensive Review of Disease, Drug Efficacy and Side Effects

Multiple myeloma (MM) is a hematologic malignancy characterized by excessive clonal proliferation of plasma cells. The treatment of multiple myeloma presents a variety of unique challenges due to the complex molecular pathophysiology and incurable status of the disease at this time. Given that MM is the second most common blood cancer with a characteristic and unavoidable relapse/refractory state during the course of the disease, the development of new therapeutic modalities is crucial. Belantamab mafodotin (belamaf, GSK2857916) is a first-in-class therapeutic, indicated for patients who have previously attempted four other treatments, including an anti-CD38 monoclonal antibody, a proteosome inhibitor, and an immunomodulatory agent. In November 2017, the FDA designated belamaf as a breakthrough therapy for heavily pretreated patients with relapsed/refractory multiple myeloma. In August 2020, the FDA granted accelerated approval as a monotherapy for relapsed or treatment-refractory multiple myeloma. The drug was also approved in the EU for this indication in late August 2020. Of note, belamaf is associated with the following adverse events: decreased platelets, corneal disease, decreased or blurred vision, anemia, infusion-related reactions, pyrexia, and fetal risk, among others. Further studies are necessary to evaluate efficacy in comparison to other standard treatment modalities and as future drugs in this class are developed.

Chemotherapy-based regimens in multiple myeloma in 2020

Multiple myeloma (MM) represents the second-most common hematologic malignancy. In the 1980s, induction therapy with alkylating agents, such as anthracyclines and steroids, as well as high-dose chemotherapy followed by autologous stem cell transplantation were the main therapeutic approaches for MM. Since the introduction of more effective drugs, such as proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies and histone deacetylase inhibitor, the new therapeutic algorithm allows of achieving a significantly improvement of prognosis. Numerous regimens, which differently combine these new agents, have been developed and tested in clinical trials. The results of these new regimens are reported each year. In this variegated new contest, old chemotherapeutic drugs still maintain an overriding weight, especially when beneficially combined with new drugs. Also, this is particular true in specific situations, such as extramedullary manifestations, in which tumor mass reduction becomes an urgent clinical need, or in case of chemotherapy-induced stem-cell mobilization. Moreover, melphalan represents the gold standard conditioning regimen since 2002, either alone or, possibly in the next future, in combination with busulfan. Finally, new chemotherapeutic agents with new mechanisms of action, such as melflufen, are in early experimental phase.

Treatment of relapsed and refractory multiple myeloma

The therapeutic strategy for relapsed and refractory multiple myeloma (RRMM) integrates a holistic approach regarding patient, disease, and drug-related factors. Patient-related factors include age, frailty status, and underlying comorbidities, especially cardiovascular and renal diseases and peripheral neuropathies that affect tolerability to multiple drug combinations or transplantations. Disease-related factors encompass these multiple patient-related factors, particularly the aggressiveness of the disease and cytogenetics. Regarding drug-related factors, the approval of novel proteasome inhibitors (such as carfilzomib and ixazomib), immunomodulatory agents (such as pomalidomide), monoclonal antibodies (such as daratumumab and elotuzumab), and new classes of drugs increasingly makes the choice treatment more complex and necessitates a comprehensive summary and an update of the efficacy and toxicities of each antimyeloma drug and its combinations. Further, careful monitoring of the side effects and supportive care throughout the course of treatment are important to achieve better outcomes for patients with RRMM.

Bendamustine With Dexamethasone in Relapsed/Refractory Systemic Light-Chain Amyloidosis: Results of a Phase II Study

PURPOSE

No established treatments exist for relapsed/refractory systemic light-chain (AL) amyloidosis. Bendamustine has shown potential in the treatment of multiple myeloma. We conducted a phase II, multicenter trial to assess the efficacy and safety of bendamustine with dexamethasone (ben-dex) in patients with persistent or progressive AL amyloidosis after ≥ 1 prior therapy.

METHODS

The trial enrolled 31 patients who received bendamustine on days 1 and 2 (100 mg/m² intravenously) with 40 mg of weekly dexamethasone in 28-day cycles until disease progression or up to 6 cycles after complete hematologic response. The primary objective was the rate of partial hematologic response (PR) or better.

RESULTS

Patients received a median of 4 cycles (range, 2-12 cycles) with 57% of patients achieving a PR or better (11% complete response, 18% very good PR). The overall organ response was 29% among the 24 patients who had measurable organ involvement. Treatment was well tolerated with no grade 5 treatment-related adverse events (AEs). Sixty-five percent of patients had a therapy-related grade 3-4 AE. The most common AEs included myelosuppression, fatigue, and nausea/vomiting. The median overall survival was 18.2 months (95% CI, 11.3 to 43.8 months), and hematologic response was associated with prolonged survival (P = .0291). The median progression-free survival was 11.3 months (95% CI, 5.0 to 15.4 months).

CONCLUSION

Overall, ben-dex is a viable treatment option with substantial efficacy and limited toxicity for patients with pretreated AL amyloidosis who have limited therapeutic options. This trial was registered at (ClinicalTrials.gov identifier: NCT01222260).

Silencing of SENP2 in Multiple Myeloma Induces Bortezomib Resistance by Activating NF-κB Through the Modulation of IκBα Sumoylation

The proteasome inhibitor bortezomib is the most successfully applied chemotherapeutic drug for treating multiple myeloma. However, its clinical efficacy reduced due to resistance development. The underlying molecular mechanisms of bortezomib resistance are poorly understood. In this study, by combining in silico analysis and sgRNA library based drug resistance screening assay, we identified SENP2 (Sentrin/SUMO-specific proteases-2) as a bortezomib sensitive gene and found its expression highly downregulated in bortezomib resistant multiple myeloma patient's samples. Furthermore, down regulation of SENP2 in multiple myeloma cell line RPMI8226 alleviated bortezomib induced cell proliferation inhibition and apoptosis, whereas, overexpression of SENP2 sensitized these cells to bortezomib treatment. We further demonstrate that knockdown of SENP2 in RPMI8226 cells increased SUMO2 conjugated IκBα that resulted in the activation of NF-κB. Taken together, we report that silencing of SENP2 and consequent activation of NF-κB through the modulation of IκBα sumoylation as a novel mechanism inducing bortezomib resistance in multiple myeloma.

How I treat a refractory myeloma patient who is not eligible for a clinical trial

Myeloma patients not eligible for clinical trials have many treatment options. Choosing the next best therapy starts with careful assessment of the biology and dynamics of the disease at relapse, as well as the condition and situation of the patient. Fit patients should be considered for triplet regimens, whereas intermediate and frail patients warrant dose-reduced triplets or doublets. An indolent serologic relapse may be treated with dose intensification, especially in a maintenance situation, whereas a rapid relapse requires a more aggressive approach with drug class change or a second-generation immunomodulatory drug (IMID) or proteasome inhibitor (PI). Monoclonal antibodies, in combination with PIs and IMIDs, have proven highly efficacious in early and late relapse. Key elements of supportive care include infection prevention, bone health, thromboprophylaxis, and management of active symptoms, such as pain and distress.

Coexistence Of A Huge Venous Thromboembolism And Bleeding Tendency In Cytokine Release Syndrome During CAR-T Therapy

Chimeric antigen receptor (CAR)-modified T cell therapy is increasingly administered for hematological malignancies. Cytokine release syndrome (CRS) is a common and severe complication of CAR-T therapy. In the present case, a 62-year-old male patient was diagnosed with relapsed and refractory multiple myeloma (RRMM). Treated with CART-CD19/BCMA therapy, his symptoms remitted, during which occasional but severe CRS associated with coagulation disorder still appeared, as evidenced by the coexistence of a huge thrombosis and bleeding tendency. Through the First Generation Sequencing, we extracted genomic DNA from the patient’s peripheral blood to analyze the distribution of polymorphism at the –572C/G site of the promoter of IL-6 gene. The results showed that the genotype of –572C/G promoter polymorphism was CC, indicating that high level of IL-6 and –572C/G polymorphism might be associated with the risk of thrombotic disorders. We concluded that immediate diagnosis and appropriate treatment of coagulopathy could reduce CRS-related mortality.

Pixantrone demonstrates significant in vitro activity against multiple myeloma and plasma cell leukemia

Treatment results for multiple myeloma and plasma cell leukemia have considerably improved, but cure remains elusive and establishing new therapeutic approaches constitutes a major unmet clinical need. We analyzed the anti-myeloma properties of the aza-anthracenedione pixantrone which has been successfully used in a phase III study for the treatment of patients with aggressive non-Hodgkin's lymphoma as monotherapy as well as in combination regimes in vitro and in an adapted in vivo model (ex ovo chicken chorioallantoic membrane (CAM) assay). Pixantrone significantly inhibited proliferation and metabolic activity of all investigated myeloma cell lines. Importantly, anti-myeloma effects were more pronounced in tumor cell lines than in stromal cells, mesenchymal stem cells, and peripheral blood mononuclear cells of healthy controls. Apoptosis of myeloma cell lines was observed only after a 7-day incubation period, indicating a fast cytostatic and a slower cytotoxic effect of this drug. Pixantrone reduced the viability of primary plasma cells of patients and induced downregulation of myeloma-cell growth in the CAM assay. Additionally, we demonstrate in vitro synergism between pixantrone and the histone deacetylase inhibitor panobinostat with respect to its anti-proliferative features. From these data, we conclude that systematic investigations of the clinical usefulness of pixantrone in the framework of controlled clinical trials are clearly indicated (e.g., in penta-refractory patients).

High-Risk Multiple Myeloma: Integrated Clinical and Omics Approach Dissects the Neoplastic Clone and the Tumor Microenvironment

Multiple myeloma (MM) is a genetically heterogeneous disease that includes a subgroup of 10–15% of patients facing dismal survival despite the most intensive treatment. Despite improvements in biological knowledge, MM is still an incurable neoplasia, and therapeutic options able to overcome the relapsing/refractory behavior represent an unmet clinical need. The aim of this review is to provide an integrated clinical and biological overview of high-risk MM, discussing novel therapeutic perspectives, targeting the neoplastic clone and its microenvironment. The dissection of the molecular determinants of the aggressive phenotypes and drug-resistance can foster a better tailored clinical management of the high-risk profile and therapy-refractoriness. Among the current clinical difficulties in MM, patients’ management by manipulating the tumor niche represents a major challenge. The angiogenesis and the stromal infiltrate constitute pivotal mechanisms of a mutual collaboration between MM and the non-tumoral counterpart. Immuno-modulatory and anti-angiogenic therapy hold great efficacy, but variable and unpredictable responses in high-risk MM. The comprehensive understanding of the genetic heterogeneity and MM high-risk ecosystem enforce a systematic bench-to-bedside approach. Here, we provide a broad outlook of novel druggable targets. We also summarize the existing multi-omics-based risk profiling tools, in order to better select candidates for dual immune/vasculogenesis targeting.

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.

Lenalidomide in combination with bendamustine and prednisolone in relapsed/refractory multiple myeloma: results of a phase 2 clinical trial (OSHO-#077)

INTRODUCTION

While lenalidomide monotherapy is established for relapsed and/or refractory multiple myeloma (MM) treatment, combination therapies including lenalidomide are still under investigation in a number of phase 2/3 studies. In the current study, a treatment regime of lenalidomide (Revlimid^®), bendamustine and prednisolone (RBP) was tested in patients with relapsed/refractory MM.

METHODS

In the previously completed phase 1 study RBP with a dose of 75 mg/m² bendamustine days 1-2, prednisolone 100 mg days 1-4 and 25 mg lenalidomide days 1-21 was well tolerated.

RESULTS

Between July 2011 and September 2013, 25 patients were included in this analysis. The median number of previous treatments was 1 (range 1-2). Twenty-two patients (88%) responded after at least two cycles of RBP (one sCR, five nCR, eight VGPR and eight PR). The median time to first haematological response was 28 days, and median time to best response was 56 days. Due to increased haematological toxicity a dose reduction in most patients required in subsequent cycles of therapy. The median progression-free and overall survival was 22 and 38 months, respectively. In conclusion RBP is a highly effective therapy for patients with relapsed/refractory MM. In contrast to our phase 1 study, dose reduction was necessary in many patients because of haematological toxicity.

Therapy for Relapsed Multiple Myeloma: Guidelines From the Mayo Stratification for Myeloma and Risk-Adapted Therapy

Life expectancy in patients with multiple myeloma is increasing because of the availability of an increasing number of novel agents with various mechanisms of action against the disease. However, the disease remains incurable in most patients because of the emergence of resistant clones, leading to repeated relapses of the disease. In 2015, 5 novel agents were approved for therapy for relapsed multiple myeloma. This surfeit of novel agents renders management of relapsed multiple myeloma more complex because of the occurrence of multiple relapses, the risk of cumulative and emergent toxicity from previous therapies, as well as evolution of the disease during therapy. A group of physicians at Mayo Clinic with expertise in the care of patients with multiple myeloma regularly evaluates the evolving literature on the biology and therapy for multiple myeloma and issues guidelines on the optimal care of patients with this disease. In this article, the latest recommendations on the diagnostic evaluation of relapsed multiple myeloma and decision trees on how to treat patients at various stages of their relapse (off study) are provided together with the evidence to support them.

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.

Multiple myeloma treatment at relapse after autologous stem cell transplantation: A practical analysis

Over the past decade, significant advances have been made in the field of multiple myeloma. Introduction of the so-called novel agents, proteasome inhibitors (PI) and immunomodulatory drugs (IMiD), and improved supportive care have resulted in significantly better outcome. Standard first line treatment in fit patients include PI and IMiD based induction, high dose melphalan with autologous hematopoietic stem cell transplantation (ASCT) and consolidation/maintenance. However, despite these progresses MM remains incurable for the majority of patients and most patients will relapse. Next generation PI (carfilzomib, ixazomib) and IMiD (pomalidomide) and new therapeutic classes: monoclonal antibody (elotuzumab, daratumumab) and pan-deacetylase inhibitors (panobinostat) have been successfully evaluated in relapse multiple myeloma. Some of these new agents are now approved for multiple myeloma treatment at relapse. However choosing the most appropriate treatment at relapse may be difficult. This review sum up the most important studies and provide evidence to choose the most relevant therapeutic strategy for relapse after ASCT, based on disease, patient and previous treatment related parameters.

Multiple myeloma: patient outcomes in real-world practice

With increasing number of therapies available for the treatment of multiple myeloma, it is timely to examine the course of patients' journeys. We investigated patient characteristics, treatment durations and outcomes, and symptom burden across the treatment pathway in Belgium, France, Germany, Italy, Spain, Switzerland and the UK. In total, 435 physicians retrospectively reviewed 4997 patient charts. Profiles of patients diagnosed with multiple myeloma during the last 12 months were similar across countries; bone pain was the most common presentation. Median duration of first-line therapy was 6 months, followed by a median treatment-free interval of 10 months; both these decreased with increasing lines of therapy, as did time to progression. Depth of response, as assessed by the treating physician, also decreased with each additional line of therapy: 74% of patients achieved at least a very good partial response at first line, compared with only 11% at fifth line. Deeper responses were associated with longer time to progression, although these were physician-judged. Toxicities and co-morbidities increased with later treatment lines, and were more likely to have led to discontinuation of treatment. These real-world data provide an insight into patient outcomes and treatment decisions being made in clinical practice.

Prolonged Response in Patient With Multiply Relapsed B-cell Acute Lymphoblastic Leukemia and Monosomy-7 to Bortezomib, Lenalidomide, and Dexamethasone

Isolated monosomy-7, a rare cytogenetic abnormality in patients with pediatric acute lymphoblastic leukemia (ALL), portends a worse prognosis. Despite improvements in treatment, outcomes for patients with relapsed ALL remain poor. Novel treatments adopted from the B-cell malignancy multiple myeloma may have a role in treatment of ALL. Bortezomib is one such agent currently in phase III trials for B and T ALL. This study presents a patient with B-cell ALL and monosomy-7 who relapsed off therapy. The combination of bortezomib, lenalidomide, and dexamethasone was used to attain remission before bone marrow transplant after conventional relapse therapy failed. A recurrence after bone marrow transplant was controlled for a prolonged period with the same therapy. The case supports the hypothesis that bortezomib, lenalidomide, and dexamethasone should be further explored in the treatment of B-cell ALL with monosomy-7.

A single-center retrospective analysis of first-line therapy of multiple myeloma with bendamustine-bortezomib-dexamethasone

The aim of this retrospective study was to evaluate the efficacy and toxicity profile of bendamustine, bortezomib, and dexamethasone (BBD) combination treatment of patients with newly diagnosed multiple myeloma (MM). BBD treatment had a response rate of 80% regarding patients with ≥ partial response (PR). Median time to best response was 87.5 days and PFS was 22 months. Median of OS was not reached. PFS of non-responding patients was significantly shortened compared to those with ≥ PR. No statistically significant differences were determined concerning age (≥ vs. < 68 years) and ISS stage (ISS stage I/II vs. III). Grade 3 hematological effects and grade 3/4 non-hematological effects occurred in 20% and 35% of patients, respectively. Most pronounced hematological adverse event was leukopenia, the most severe non-hematological ones affected the cardiovascular system. In summary, BBD treatment was of acceptable efficacy in patients with newly diagnosed MM and exhibited rather low toxicity.

Multiple myeloma in the marrow: pathogenesis and treatments

Multiple myeloma (MM) is a B cell malignancy resulting in osteolytic lesions and fractures. In the disease state, bone healing is limited owing to increased osteoclastic and decreased osteoblastic activity, as well as an MM-induced forward-feedback cycle where bone-embedded growth factors further enhance tumor progression as bone is resorbed. Recent work on somatic mutation in MM tumors has provided insight into cytogenetic changes associated with this disease; the initiating driver mutations causing MM are diverse because of the complexity and multitude of mutations inherent in MM tumor cells. This manuscript provides an overview of MM pathogenesis by summarizing cytogenic changes related to oncogenes and tumor suppressors associated with MM, reviewing risk factors, and describing the disease progression from monoclonal gammopathy of undetermined significance to overt MM. It also highlights the importance of the bone marrow microenvironment (BMM) in the establishment and progression of MM, as well as associated MM-induced bone disease, and the relationship of the bone marrow to current and future therapeutics. This review highlights why understanding the basic biology of the healthy and diseased BMM is crucial in the quest for better treatments and work toward a cure for genetically diverse diseases such as MM.

Current and emerging triplet combination therapies for relapsed and refractory multiple myeloma

Despite significant improvement in outcomes have been observed for multiple myeloma (MM) patients over the past 10-15 years, mainly due to the introduction of novel agents targeting the tumor clone and the bone marrow microenvironment, treatment of refractory and/or relapsed (RR) disease remains a challenge, particularly for patients who have failed prior bortezomib- and lenalidomide-based therapies. More recently, new drugs with different mechanisms of action, including second generation proteasome inhibitors, third generation immunomodulatory drugs, histone deacetylase inhibitors and monoclonal antibodies, have been developed and are under investigation, further increasing treatment options for RRMM patients. Overall, novel agent-based triplet combinations demonstrated superior response rates and prolonged disease control when compared with two-drug regimens in several randomized clinical trials, without adding any relevant additional toxicity. Salvage triplet therapies are likely to play a key role in overcoming drug-resistance and hold promise to further improve long-term outcomes of RRMM patients.

New pharmacotherapy options for multiple myeloma

INTRODUCTION

Novel agents and the availability of autologous stem-cell transplantation have revolutionized the treatment of patients with multiple myeloma. First-generation novel agents namely thalidomide, lenalidomide, and bortezomib have significantly improved response and survival of patients. Second-generation novel agents such as pomalidomide, carfilzomib, and monoclonal antibodies are being tested both in the newly diagnosed and relapse settings, and results are promising.

AREAS COVERED

In this review article, the main results derived from Phase III trials with thalidomide, lenalidomide, and bortezomib for the treatment of myeloma patients, both at diagnosis and at relapse, are summarized. Data about second-generation novel agents such as pomalidomide and carfilzomib are also reported. Newer effective drugs currently under investigation and the promising results with monoclonal antibodies are described.

EXPERT OPINION

The availability of new effective drugs has considerably increased the treatment options for myeloma patients. A sequential approach including induction, transplantation (when possible), consolidation, and maintenance is an optimal strategy to achieve disease control and prolong survival. Despite these improvements, the best combination, the optimal sequence, and the proper target of newer drugs need to be defined.

An update in treatment options for multiple myeloma in nontransplant eligible patients

INTRODUCTION

Despite the fact that multiple myeloma (MM) is still an incurable disease, the outcome of patients who are eligible and ineligible for high-dose therapy has dramatically improved with the introduction of novel agents, that is proteasome inhibitors (PIs) and immunomodulatory agents (IMiDs). However, this improvement is often not seen in elderly patients (above 75 years).

AREAS COVERED

This review will focus on the impact of known prognostic factors in elderly MM patients, and risk factors to identify frail elderly patients. Furthermore, data on known and novel PIs and IMiDs, as well as data on other promising novel treatment strategies, chosen based on current practice and anticipated timely approval, will be discussed. Novel treatment strategies include the use of monoclonal antibodies, such as elotuzumab, daratumumab, SAR650984 and more targeted therapies, such as histone deacetylase inhibitors, kinesin spindle protein inhibitors, and selective inhibitors of nuclear export.

EXPERT OPINION

Besides efficacy of treatment, toxicity and quality of life play an important role in treatment choice. Treatment and treatment dosing for the frail elderly as well as risk factors to identify the frail elderly require further consideration, as these patients frequently do not benefit from these novel agents due to early discontinuation of treatment due to toxicity.

Clinical characteristics of patients with relapsed multiple myeloma

Although survival outcomes have improved over the last decade for patients with multiple myeloma (MM), few patients remain free of disease and most inevitably relapse. Selecting a treatment for patients with relapsed MM is challenging given the number and diversity of regimens patients may have previously received, which can affect subsequent therapeutic choices. Importantly, a number of patient- and disease-related factors can also have an effect on treatment choice, treatment efficacy, and tolerability; thus, an understanding of the heterogeneity of patients in the setting of relapsed MM is important for appropriate treatment selection. Here, we review select patient and disease characteristics reported in key interventional and observational studies in relapsed MM (including age, sex, race, and the presence of high-risk disease, renal impairment, or peripheral neuropathy at baseline) to examine common and disparate features of patients with relapsed MM. As therapeutic regimens can have varying efficacy and/or tolerability in patients depending on these factors, we also provide treatment recommendations for patients with select baseline characteristics.

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.

Treatment options for relapsed and refractory multiple myeloma

Over the last few decades, significant improvement in outcomes has been observed for myeloma patients, mainly as a result of the use of currently available approved antimyeloma agents, along with combining autologous stem cell transplantation in the treatment of myeloma. With more targeted agents in development, the treatment of a myeloma patient at relapse has become complicated and, as a consequence, results in vast heterogeneity in treatment patterns. Although a consensus on the timing of initiation of treatment, the choice of agents to be used, and the role of transplant is less clear, we describe an evidence-based approach and the factors to consider upon relapse. We describe additional newer agents and targets that are under development, with the goal of achievement of durable remissions for myeloma patients.

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.

Trial Watch: Proteasomal inhibitors for anticancer therapy

The so-called "ubiquitin-proteasome system" (UPS) is a multicomponent molecular apparatus that catalyzes the covalent attachment of several copies of the small protein ubiquitin to other proteins that are generally (but not always) destined to proteasomal degradation. This enzymatic cascade is crucial for the maintenance of intracellular protein homeostasis (both in physiological conditions and in the course of adaptive stress responses), and regulates a wide array of signaling pathways. In line with this notion, defects in the UPS have been associated with aging as well as with several pathological conditions including cardiac, neurodegenerative, and neoplastic disorders. As transformed cells often experience a constant state of stress (as a result of the hyperactivation of oncogenic signaling pathways and/or adverse microenvironmental conditions), their survival and proliferation are highly dependent on the integrity of the UPS. This rationale has driven an intense wave of preclinical and clinical investigation culminating in 2003 with the approval of the proteasomal inhibitor bortezomib by the US Food and Drug Administration for use in multiple myeloma patients. Another proteasomal inhibitor, carfilzomib, is now licensed by international regulatory agencies for use in multiple myeloma patients, and the approved indications for bortezomib have been extended to mantle cell lymphoma. This said, the clinical activity of bortezomib and carfilzomib is often limited by off-target effects, innate/acquired resistance, and the absence of validated predictive biomarkers. Moreover, the antineoplastic activity of proteasome inhibitors against solid tumors is poor. In this Trial Watch we discuss the contribution of the UPS to oncogenesis and tumor progression and summarize the design and/or results of recent clinical studies evaluating the therapeutic profile of proteasome inhibitors in cancer patients.

Bendamustine in combination with thalidomide and dexamethasone is a viable salvage option in myeloma relapsed and/or refractory to bortezomib and lenalidomide

Treatment options are limited in myeloma relapsed or refractory to both bortezomib and lenalidomide (double-relapsed/refractory multiple myeloma; DRMM). Bendamustine is an antitumour agent that has efficacy in relapsed myeloma. We retrospectively analysed data from 30 DRMM patients who received a combination of bendamustine, thalidomide and dexamethasone (BTD) in 28-day treatment cycles. Bendamustine was administered with a cumulative dose of up to 200 mg/m(2). Thalidomide (50-150 mg) was given daily as tolerated, and dexamethasone was given at an equivalent dose of up to 160 mg per cycle. A median of 5 (2-9) treatment cycles were administered per patient. Twenty-six patients (87 %) achieved stable disease or better. At a median follow-up time of 12.1 (2.3-21.5) months, median (95 % CI) progression-free survival and overall survival were 4.0 (2.6-5.3) months and 7.2 (5.2-9.2) months, respectively. The most common grade 3-4 adverse events were haematological: anaemia (n = 8, 34.8 %), neutropenia (n = 16, 69.6 %) and thrombocytopenia (n = 10, 43.5 %). Non-haematological toxicities included pain (n = 3, 13.0 %), infection (n = 7, 30.4 %) and sensory neuropathy (n = 1, 4.3 %). We propose that BTD is a viable salvage treatment option for DRMM patients.

Bendamustine and prednisone in combination with bortezomib (BPV) in the treatment of patients with newly diagnosed/untreated multiple myeloma

INTRODUCTION

Bortezomib is a proteasome inhibitor that has shown important clinical efficacy either as a single agent or in combination in patients with multiple myeloma (MM). In the present protocol, bortezomib was combined with bendamustine and prednisone, in order to assess the efficacy and safety of this combination therapy in patients with newly diagnosed/untreated MM.

METHODS

Between June 2006 and October 2013, 49 patients with newly diagnosed/untreated MM were treated with bendamustine 60 mg/m(2) on days 1 and 2, bortezomib 1.3 mg/m(2) on days 1, 4, 8 and 11, and prednisone 100 mg on days 1, 2, 4, 8 and 11 bendamustine, prednisone and bortezomib (BPV) once every 21 days. Patients were divided into three groups: group A (n = 19) consisted of patients with normal renal function or mild dysfunction (eGFR ≥ 60 ml/min), group B (n = 15) patients with moderate or severe renal dysfunction (eGFR 15-59 ml/min) and group C (n = 15) patients with renal failure/dialysis (eGFR <15 ml/min).

RESULTS

A median number of two (range 1-5) BPV treatment cycles were given to the patients. The majority of the patients (n = 40, 82 %) responded after at least one cycle of BPV therapy with five stringent complete responses (CRs), nine near complete responses, 12 very good partial responses and 14 partial responses. Five patients had MR, three stable and one progressive disease. After a median observation time of 13 months, progression-free survival (PFS) and overall survival (OS) at 12 months were 92 and 94 %, respectively, for patients with normal renal function or mild renal dysfunction (group A) and 83 and 93 %, respectively, for patients with moderate or severe renal dysfunction (group B). Outcome for these patients was slightly better but not statistically significantly better than that for patients with renal failure/dialysis (group C), who had a PFS, and OS of 66 % (p = 0.08) and 73 % (p = 0.05), respectively. These results indicate that this BPV combination is feasible, effective and well tolerated in patients with newly diagnosed MM and normal or impaired renal function.

Salvage therapy of multiple myeloma: the new generation drugs

During the past decade, overall results of treatment of multiple myeloma (MM) have been improved and survival curves are now significantly better with respect to those obtained with historical treatment. These improvements are linked to a deeper knowledge of the biology of disease and to the introduction in clinical practice of drugs with different mechanism of action such as proteasome inhibitors and immunomodulatory drugs (IMiDs). However, MM remains in most cases an incurable disease. For patients who relapse after treatment with novel agents, the prognosis is dismal and new drugs and therapeutic strategies are required for continued disease control. In this review, we summarize new insights in salvage therapy for relapsed/refractory MM as emerging from recent clinical trials exploring the activity of bendamustine, new generation proteasome inhibitors, novel IMiDs, monoclonal antibodies, and drugs interfering with growth pathways.