Characterisation of haematological profiles and low risk of thromboembolic events with bortezomib in patients with relapsed multiple myeloma

A systematic review and meta-analysis of carfilzomib-associated thrombocytopenia as an adverse event in patients with multiple myeloma

Background

Carfilzomib is a second-generation proteasome inhibitor (PI) used for combination therapy with dexamethasone and/or lenalidomide in patients with relapsed or refractory multiple myeloma. Reports indicate that PIs have a unique toxicity profile that includes thrombocytopenia as a hematologic adverse event; however, its occurrence has not yet been quantified systematically.

Objectives

The main objective of our systematic review and meta-analysis is to investigate the incidence of thrombocytopenia in patients with multiple myeloma after treatment with carfilzomib.

Design

Selection of studies and meta-analysis of trials was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement.

Data sources and methods

Two investigators performed an independent literature search of PubMed, Web of Science, SciFinder, the Cochrane Central Register of Controlled Trials, as well as the US and EU clinical trials registries. The cumulative incidence and overall relative risk were calculated with the random effect model using RevMan and R statistical software.

Results

The analysis included a total of 9237 patients, 2516 patients in single-arm studies and 6721 patients in randomized controlled trials (RCTs). A total of 47 studies were included; among these, 14 were RCTs. Analysis of currently available data showed that treatment with carfilzomib may increase the incidence of all-grade thrombocytopenia, and this correlated with the dose used. With supportive therapy alone, the incidence is 26%. The addition of carfilzomib to the treatment results in a 37% increase in incidence, whereas with bortezomib, the increase is slightly lower at 34%. Surprisingly, when treatment with carfilzomib and bortezomib was compared, bortezomib was found to be more likely to exacerbate high-grade thrombocytopenia (7%) than carfilzomib (3%).

Conclusion

Clarification of these associations suggests that clinicians should be aware of the potential risk of high-grade thrombocytopenia occurring and monitor patients closely to take appropriate measures.

Trial registration

Registered in PROSPERO under the number CRD42022314378.

Selinexor in multiple myeloma

INTRODUCTION

Selinexor, an XPO1 inhibitor, has emerged as a promising therapeutic option in the challenging landscape of relapsed/refractory multiple myeloma (RRMM).

AREAS COVERED

This article provides a review of selinexor, with a focus on available clinical studies involving MM patients and its safety profile. Clinical trials, such as STORM and BOSTON, have demonstrated its efficacy, particularly in combination regimens, showcasing notable overall response rates (ORR) and prolonged median progressionfree survival (mPFS). Selinexor's versatility is evident across various combinations, including carfilzomibdexamethasone (XKd), lenalidomidedexamethasone (XRd), and pomalidomidedexamethasone (XPd), with efficacy observed even in tripleclass refractory and highrisk patient populations. However, challenges, including resistance mechanisms and adverse events, necessitate careful management. Realworld evidence also underscores selinexor's effectiveness in RRMM, though dose adjustments and supportive measures remain crucial. Ongoing trials are exploring selinexor in diverse combinations and settings, including pomalidomidenaïve patients and postautologous stem cell transplant (ASCT) maintenance.

EXPERT OPINION

The evolving landscape of selinexor's role in the sequencing of treatment for RRMM, its potential in highrisk patients, including those with extramedullary disease, as revealed in the most recent international meetings, and ongoing investigations signal a dynamic era in myeloma therapeutics. Selinexor emerges as a pivotal component in multidrug strategies and innovative combinations.

Venous thromboembolism prophylaxis and multiple myeloma patients in real-life: Results of a large survey and clinical guidance recommendations from the IFM group

Venous thromboembolism (VTE) remains a critical issue in the management of patients with multiple myeloma (MM), particularly when immunomodulatory drugs (IMiDs) combined with dexamethasone therapy are being prescribed as first-line and relapse therapy. One possible explanation for the persistent high rates of VTE, is the use of inappropriate thromboprophylaxis strategies for patients starting antimyeloma treatment. To tackle the issue, the Intergroupe francophone du myélome (IFM) offered convenient guidance for VTE thromboprophylaxis in MM patients initiating systemic therapy. This guidance is mainly supported by the results of a large survey on the clinical habits regarding VTE of physicians who are substantially involved in daily care of MM patients. VTE prophylaxis should be considered for all patients treated with IMiDs in combination with dexamethasone, in the absence of significant comorbidities, such as renal failure or bleeding risk. Anticoagulant should be preferred to antiplatelet agents for thromboprophylaxis. Despite the absence of large randomized controlled trials comparing those attitudes/options, available data on direct oral anticoagulants, which are already used in daily management of MM patients, are consistent with their potential usefulness for VTE prophylaxis in such patients. However, in order to implement a personalized continuous improvement strategy, clinicians must to be organized to collect all the data regarding this management. In other situations, thromboprophylaxis should be evaluated by using risk models and after careful evaluation of the risk/benefit ratio.

Thrombosis in multiple myeloma: risk stratification, antithrombotic prophylaxis, and management of acute events. A consensus-based position paper from an ad hoc expert panel

The introduction of new therapeutic agents for multiple myeloma (MM), including proteasome inhibitors, immunomodulatory drugs, and monoclonal antibodies, has improved the outcomes of patients but, in parallel, has changed the frequency and epidemiology of thrombotic events. Thrombosis is now a significant cause of morbidity and mortality in MM patients, and optimal thromboprophylaxis is far from being reached. Moving from the recognition that the above issue represents an unmet clinical need, an expert panel assessed the scientific literature and composed a framework of recommendations for improving thrombosis control in patients who are candidates for active treatment for MM. The panel generated key clinical questions using the criterion of clinical relevance through a Delphi process. It explored four domains, i.e., thrombotic risk factors and risk stratification, primary thromboprophylaxis, management of acute thrombotic events, and secondary thromboprophylaxis. The recommendations issued may assist hematologists in minimizing the risk of thrombosis and guarantee adherence to treatment in patients with MM who are candidates for active treatment.

A Kunitz-type inhibitor from tick salivary glands: A promising novel antitumor drug candidate

Salivary glands are vital structures responsible for successful tick feeding. The saliva of ticks contains numerous active molecules that participate in several physiological processes. A Kunitz-type factor Xa (FXa) inhibitor, similar to the tissue factor pathway inhibitor (TFPI) precursor, was identified in the salivary gland transcriptome of Amblyomma sculptum ticks. The recombinant mature form of this Kunitz-type inhibitor, named Amblyomin-X, displayed anticoagulant, antiangiogenic, and antitumor properties. Amblyomin-X is a protein that inhibits FXa in the blood coagulation cascade and acts via non-hemostatic mechanisms, such as proteasome inhibition. Amblyomin-X selectively induces apoptosis in cancer cells and promotes tumor regression through these mechanisms. Notably, the cytotoxicity of Amblyomin-X seems to be restricted to tumor cells and does not affect non-tumorigenic cells, tissues, and organs, making this recombinant protein an attractive molecule for anticancer therapy. The cytotoxic activity of Amblyomin-X on tumor cells has led to vast exploration into this protein. Here, we summarize the function, action mechanisms, structural features, pharmacokinetics, and biodistribution of this tick Kunitz-type inhibitor recombinant protein as a promising novel antitumor drug candidate.

Adverse event management in the TOURMALINE-MM3 study of post-transplant ixazomib maintenance in multiple myeloma

The phase 3, double-blind, placebo-controlled TOURMALINE-MM3 study (NCT02181413) demonstrated improved progression-free survival with ixazomib maintenance versus placebo post autologous stem cell transplant (ASCT) in multiple myeloma patients. We report additional safety data from TOURMALINE-MM3 to inform adverse event (AE) management recommendations. Patients were randomized 3:2 to receive ixazomib (n = 395) or placebo (n = 261) on days 1, 8, and 15 of 28-day cycles for ~ 2 years or until progressive disease/toxicity. The initial 3-mg ixazomib dose was escalated to 4 mg in cycle 5, if tolerated in cycles 1-4. Safety was a secondary endpoint assessed in all treated patients; AEs were graded using Common Terminology Criteria for AEs v4.03. The rate of grade ≥ 3 AEs was higher in the ixazomib arm (19%) than in the placebo arm (5%), but the rate of discontinuation due to AEs was similar (7% vs. 5%). For AEs of clinical interest, rates were higher with ixazomib versus placebo: nausea 39% versus 15%, vomiting 27% versus 11%, diarrhea 35% versus 24%, thrombocytopenia 13% versus 3%, and peripheral neuropathy 19% versus 15%. However, the majority of events were low-grade, manageable with supportive therapy or dose reduction, and reversible, and did not result in discontinuation. There was no evidence of cumulative, long-term, or late-onset toxicity with ixazomib maintenance. Ixazomib is an efficacious and tolerable option for post-ASCT maintenance. AEs associated with ixazomib maintenance can be managed in the context of routine post-ASCT supportive care due to the limited additional toxicity. ClinicalTrials.gov NCT02181413.

Venous thromboembolism risk with contemporary lenalidomide-based regimens despite thromboprophylaxis in multiple myeloma: A systematic review and meta-analysis

BACKGROUND

Thromboprophylaxis is routinely used with lenalidomide-based regimens in multiple myeloma because of a substantial risk of venous thromboembolism (VTE). However, little is known about the incidence of VTE with contemporary lenalidomide-based regimens. The objective of the current study was to estimate the incidence of VTE despite thromboprophylaxis with currently used lenalidomide-based regimens in patients with myeloma.

METHODS

The Ovid MEDLINE, Embase, and Cochrane databases were queried from study inception to January 2019 for keywords to cover the following concepts: "lenalidomide," "venous thromboembolism," and "multiple myeloma." Phase 1, 2, and 3 clinical trials evaluating lenalidomide-based regimens with thromboprophylaxis were included. The pooled incidence rate of VTE was estimated using a random-effects model.

RESULTS

The search generated 1372 citations, with 51 clinical trials and 9069 patients included for analysis. The most common thromboprophylaxis agents were aspirin, low-molecular-weight heparin or warfarin, administered either per risk-stratification or at investigators' discretion. The pooled incidence of VTE in trials of patients who had newly diagnosed and relapsed/refractory myeloma was 6.2% (95% CI, 5.4%-7.1%) over median treatment durations ranging from 2 to 34 cycles, which translated into 1.2 VTE events per 100 patient-cycles (95% CI, 0.9-1.7 VTE events per 100 patient-cycles). Among contemporary regimens, the risk of VTE was low with combined lenalidomide and low-dose dexamethasone (0.2 [95% CI, 0.1-0.6] events/100 patient-cycles) and lenalidomide maintenance (0.0 [95% CI, 0.0-0.7] events per 100 patient-cycles). VTE risk was higher with combined lenalidomide and low-dose dexamethasone plus proteasome inhibitors (1.3 [95% CI, 0.7-2.3] events per 100 patient-cycles).

CONCLUSIONS

Despite adequate thromboprophylaxis, lenalidomide-based regimens have a substantial risk of VTE in controlled clinical trial settings. Further studies are needed on new thromboprophylaxis strategies with regimens that have a high VTE risk.

Proteostasis In The Endoplasmic Reticulum: Road to Cure

The endoplasmic reticulum (ER) is an interconnected organelle that is responsible for the biosynthesis, folding, maturation, stabilization, and trafficking of transmembrane and secretory proteins. Therefore, cells evolve protein quality-control equipment of the ER to ensure protein homeostasis, also termed proteostasis. However, disruption in the folding capacity of the ER caused by a large variety of pathophysiological insults leads to the accumulation of unfolded or misfolded proteins in this organelle, known as ER stress. Upon ER stress, unfolded protein response (UPR) of the ER is activated, integrates ER stress signals, and transduces the integrated signals to relive ER stress, thereby leading to the re-establishment of proteostasis. Intriguingly, severe and persistent ER stress and the subsequently sustained unfolded protein response (UPR) are closely associated with tumor development, angiogenesis, aggressiveness, immunosuppression, and therapeutic response of cancer. Additionally, the UPR interconnects various processes in and around the tumor microenvironment. Therefore, it has begun to be delineated that pharmacologically and genetically manipulating strategies directed to target the UPR of the ER might exhibit positive clinical outcome in cancer. In the present review, we summarize recent advances in our understanding of the UPR of the ER and the UPR of the ER-mitochondria interconnection. We also highlight new insights into how the UPR of the ER in response to pathophysiological perturbations is implicated in the pathogenesis of cancer. We provide the concept to target the UPR of the ER, eventually discussing the potential of therapeutic interventions for targeting the UPR of the ER for cancer treatment.

Cardiovascular Complications Associated with Multiple Myeloma Therapies: Incidence, Pathophysiology, and Management

PURPOSE OF REVIEW

Multiple myeloma is a common hematologic malignancy characterized by recurrent relapsing disease course requiring use of various therapies. Over the past few decades, significant advancements in the treatment of myeloma have occurred including routine use of proteasome inhibitors and immunomodulatory drugs. These have effectively improved survival; however, some also have increased risk of cardiovascular toxicity. Here, we will review the incidence, pathophysiology, and management of cardiovascular complications associated with antimyeloma agents.

RECENT FINDINGS

Cardiovascular complications associated with myeloma treatment are common. These cardiovascular complications include accelerated hypertension, ischemic heart disease, congestive heart failure, arrhythmia, pulmonary hypertension, venous thromboembolism, and arterial thromboembolism. Thromboprophylactic strategies during treatment with immunomodulatory agents and screening strategies to detect changes in myocardial function prior to the development of overt heart failure have occurred. Cardiovascular complications associated with proteasome inhibitors and immunomodulatory drugs are an important component in supportive care of patients with myeloma. The incidence of cardiotoxicity is high, and, as such, early intervention and collaborative efforts between cardiologists and oncologists to mitigate and effectively manage these complications are imperative. Additional studies are needed to clarify the underlying pathophysiology and evaluate effective strategies for prevention and treatment.

Bortezomib therapy in a real-world setting in patients with relapsed or refractory multiple myeloma

Bortezomib is a proteasome inhibitor, approved for treating newly diagnosed and relapsed multiple myeloma (MM). This realworld, multicenter, observational, non-interventional study of bortezomib was designed to collect and analyze prospective data in Taiwanese patients with relapsed or refractory MM. The primary endpoints included clinical effectiveness outcomes (disease response, disease progression [PD], time-to-response, time-toprogression, response duration, and overall survival [OS]). Secondary endpoints were safety and healthcare resource utilization.

Total 100 patients (median [range] age 64.9 [37.0-85.5] years) were enrolled; 47 patients completed the study. Of the withdrawn patients (n=53), there were 48 deaths (PD-related death: n=35, adverse events [AEs]-related: n=12, other reason: n=1), and 5 due to loss to follow-up. Four patients in Cycle 1, 6 patients each in Cycle 2 and 5, 7 in Cycle 3, 10 patients in Cycle 4, 5 patients in Cycle 6, and 3 patients each in Cycle 7 and 8 achieved overall response during the study. Time-to-response was 4.68 months (95%CI: 3.2, NE) and response duration was 10.08 months (95%CI: 2.3, 28.6). Median OS was 9.8 months (95%CI: 3.8, 13.7), and median time-to-progression was 11.3 months (95%CI: 6.2, 20.2). Most common non-hematological AEs were diarrhea (n=32) and hypoesthesia (n=25); most common hematological AE was thrombocytopenia (n=18).

Efficacy and safety profile of bortezomib in Taiwanese patients with MM was similar to global and other Asian population. Study provides a critical insight on use of bortezomib in realworld clinical practice, which can be helpful for Taiwanese healthcare providers’ decision-making processes.

Preclinical evaluation of Amblyomin-X, a Kunitz-type protease inhibitor with antitumor activity

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Amblyomin-X is a recombinant protein with selective antitumor activity, causing tumor reduction in vivo.

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Acute and subchronic toxicity studies shows low toxicity in healthy mice, with reversible adverse effects.

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Amblyomin-X toxicity profile was defined.

Amblyomin-X, a Kunitz-type protease inhibitor, is a recombinant protein that selectively induces apoptosis in tumor cells and promotes tumor reduction in vivo in melanoma animal models. Furthermore, Amblyomin-X was able to drastically reduce lung metastasis in a mice orthotopic kidney tumor model. Due to its antitumor activity, Amblyomin-X potential to become a new drug is currently under investigation, therefore the aim of the present study was to perform preclinical assays to evaluate Amblyomin-X toxicity in healthy mice. Exploratory toxicity assays have shown that treatment with 512 mg/kg of Amblyomin-X lead to animal mortality, therefore two groups of treatment were evaluated in the present work: in the acute toxicity assay, animals were injected once with doses ranging from 4 to 256 mg/kg of Amblyomin-X, while in the subacute toxicity assay, animals were injected with 0.25, 0.57 and 1 mg/kg of Amblyomin-X daily, during 28 days. Following this treatment regimens, Amblyomin-X did not cause any mortality; moreover, toxicity signs were discrete, reversible and observed only at the higher doses, thus establishing a safety profile for administration in mice, which can be further used to determine the dose translation of this novel drug candidate for treatment in other species.

The power of proteasome inhibition in multiple myeloma

INTRODUCTION

Proteasome inhibitors (PIs) are therapeutic backbones of multiple myeloma treatment, with PI-based therapies being standards of care throughout the treatment algorithm. Proteasome inhibition affects multiple critical signaling pathways in myeloma cells and interacts synergistically with mechanisms of action of other conventional and novel agents, resulting in substantial anti-myeloma activity and at least additive effects. Areas covered: This review summarizes the biologic effects of proteasome inhibition in myeloma and provides an overview of the importance of proteasome inhibition to the current treatment algorithm. It reviews key clinical data on three PIs, specifically bortezomib, carfilzomib, and ixazomib; assesses ongoing phase 3 trials with these agents; and looks ahead to the increasingly broad role of both approved PIs and PIs under investigation in the frontline and relapsed settings. Expert commentary: Progress to date with PIs in multiple myeloma has been impressive, but there remain unmet needs and challenges, as well as increasing opportunities to optimize the use of these agents. Understanding discrepancies between PIs in terms of efficacy and safety profile is a key goal of ongoing research, along with proteomics-based efforts to identify potential biomarkers of sensitivity and resistance, thereby enabling increasingly personalized treatment approaches in the future.

Dose and Schedule Selection of the Oral Proteasome Inhibitor Ixazomib in Relapsed/Refractory Multiple Myeloma: Clinical and Model-Based Analyses

Background

The oral proteasome inhibitor ixazomib has been approved by regulatory authorities around the world, including in the United States and the European Union, for the treatment of patients with multiple myeloma (MM) who have received at least one prior therapy, based on the pivotal phase III TOURMALINE-MM1 study.

Objective

The objective of this study was to quantitatively characterize the benefit–risk profile of ixazomib in relapsed/refractory MM in support of the approved dose and schedule.

Methods

We report early-phase study data and exposure–response analyses of TOURMALINE-MM1 data that support the selection of the recommended ixazomib dose and schedule.

Results

Single-agent ixazomib studies showed a favorable efficacy/safety profile with weekly versus twice-weekly dosing; a phase I/II study of ixazomib in combination with lenalidomide and dexamethasone (IRd) identified a weekly ixazomib dose that offered an acceptable efficacy/safety profile. In IRd exposure–response analyses from TOURMALINE-MM1, ixazomib systemic exposure was not a significant predictor of progression-free survival or probability of response. Significant associations were observed between ixazomib exposure and the probability of grade ≥3 anemia and thrombocytopenia, and grade ≥2 diarrhea, fatigue, nausea, peripheral neuropathy, and rash. Additionally, higher ixazomib exposure was associated with lower lenalidomide relative dose intensity.

Conclusions

These analyses support a favorable benefit–risk profile for weekly ixazomib 4.0 mg on days 1, 8, and 15 of 28-day cycles, which was selected for the phase III TOURMALINE registration program.

Trial Registration Numbers

ClinicalTrials.gov NCT00932698, NCT00963820, NCT01217957, NCT01564537

Electronic supplementary material

The online version of this article (doi:10.1007/s11523-017-0524-3) contains supplementary material, which is available to authorized users.

Bortezomib-based therapy for transplant-ineligible East Asian patients with newly diagnosed mantle-cell lymphoma

Introduction

This subgroup analysis of the LYM-3002 Phase III study (NCT00722137) investigated whether substituting bortezomib for vincristine in frontline R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) therapy could improve outcomes in East Asian patients with newly diagnosed mantle-cell lymphoma (MCL).

Materials and methods

A total of 121 East Asian patients from China, Taiwan, Japan, and the Republic of Korea with stage II–IV MCL who were ineligible or not considered for stem-cell transplantation were enrolled to six to eight 21-day cycles of R-CHOP or VR-CAP (R-CHOP with bortezomib replacing vincristine).

Results

The primary end point was progression-free survival. After a median follow-up of 42.4 months, median progression-free survival in East Asian patients was 13.9 (R-CHOP) versus 28.6 (VR-CAP) months (HR 0.7, P=0.157; 43% improvement with VR-CAP). Secondary end points (R-CHOP vs VR-CAP), including complete response rate (47% vs 63%), duration of complete response (median 16.6 vs 46.7 months), and treatment-free interval (median 21 vs 46.5 months), were improved with VR-CAP. VR-CAP was associated with increased but manageable toxicity. The most frequent adverse events were hematologic toxicities.

Conclusion

VR-CAP was effective in East Asian patients with newly diagnosed MCL, and could be considered for patients in whom stem-cell transplantation is not an option.

The proteasome and proteasome inhibitors in multiple myeloma

Proteasome inhibitors are one of the most important classes of agents to have emerged for the treatment of multiple myeloma in the past two decades, and now form one of the backbones of treatment. Three agents in this class have been approved by the United States Food and Drug Administration-the first-in-class compound bortezomib, the second-generation agent carfilzomib, and the first oral proteasome inhibitor, ixazomib. The success of this class of agents is due to the exquisite sensitivity of myeloma cells to the inhibition of the 26S proteasome, which plays a critical role in the pathogenesis and proliferation of the disease. Proteasome inhibition results in multiple downstream effects, including the inhibition of NF-κB signaling, the accumulation of misfolded and unfolded proteins, resulting in endoplasmic reticulum stress and leading to the unfolded protein response, the downregulation of growth factor receptors, suppression of adhesion molecule expression, and inhibition of angiogenesis; resistance to proteasome inhibition may arise through cellular responses mediating these downstream effects. These multiple biologic consequences of proteasome inhibition result in synergistic or additive activity with other chemotherapeutic and targeted agents for myeloma, and proteasome inhibitor-based combination regimens have become established as a cornerstone of therapy throughout the myeloma treatment algorithm, incorporating agents from the other key classes of antimyeloma agents, including the immunomodulatory drugs, monoclonal antibodies, and histone deacetylase inhibitors. This review gives an overview of the critical role of the proteasome in myeloma and the characteristics of the different proteasome inhibitors and provides a comprehensive summary of key clinical efficacy and safety data with the currently approved proteasome inhibitors.

Efficacy and tolerability of bortezomib and dexamethasone in newly diagnosed multiple myeloma

Background:

Outcome in multiple myeloma (MM) has improved substantially over recent years as a result of the availability of multiple novel agents with acceptable safety profile.

Study Design:

Prospective observational study at a tertiary care institute.

Methods:

Twenty-five newly diagnosed patients of MM were treated with bortezomib and dexamethasone induction with monitoring for response and safety, followed by peripheral blood autologous stem cell transplant (PBASCT) in eligible patients or maintenance.

Results:

Out of 25 patients, 32% attained complete response (CR), 56% very good partial response (VGPR), 4% PR, and 8% showed no response. The overall response rate was 92%. In our study, 56% of patients showed hematological side effects, out of which thrombocytopenia was seen in 32%, anemia in 16%, and leukopenia in 8%. Six patients developed bortezomib-induced peripheral neuropathy, out of which four had grade 1 (66.66%), one had grade 2 (16.66%), and 1 (16.66%) had grade 3 toxicity. Sixteen patients were eligible for PBASCT, out of which eight patients received this therapy while as remaining eight patients opted for two more cycles of induction therapy followed by maintenance. After completing 18 months of maintenance, all the eight patients who underwent PBASCT were in CR. Out of the 15 patients who did not receive PBASCT five attained CR, eight VGPR while as two patients relapsed.

Conclusion:

Bortezomib plus dexamethasone is highly effective and well-tolerated regimen for frontline treatment of MM with a higher quality of response in an advanced stage and renal failure patients.

Pharmacokinetic study of bortezomib administered intravenously in Taiwanese patients with multiple myeloma

This phase 4, single-arm, non-randomized, open-label, post approval commitment study evaluated the pharmacokinetics and safety of bortezomib in Taiwanese patients with multiple myeloma. Patients (≥20 years) with measurable secretory multiple myeloma (serum monoclonal IgG ≥10, IgA/IgE ≥5, IgD ≥0.5 g/L, IgM present [regardless of level], and urine M protein of ≥200 mg/24 h) received intravenous bortezomib 1.3 mg/m² , twice weekly for 2 weeks, followed by a 10-day resting phase (days 12 to 21). Pharmacokinetics and safety were assessed at pre-specified time points. All enrolled patients (n = 18, men: 11; women: 7) completed the study. Mean (SD) C_max (maximum observed plasma concentration) on day 11 was 266 (77.5) ng/mL, approximately 60% higher compared with non-Asian patients receiving a similar bortezomib regimen but with overlapping ranges. Because of the protracted terminal phase, half-life (t_1/2 ), area under the plasma concentration-time curve from time 0 to infinity (AUC_∞ ), volume of distribution (V_z ), and systemic clearance were not assessable. All patients experienced treatment-emergent adverse events (TEAEs); 78% were drug-related. Most commonly reported TEAEs were thrombocytopenia (n = 11 [61%]), neutropenia (n = 9 [50%]), leukopenia (n = 6 [33%]), and diarrhoea (n = 6 [33%]); the most common serious adverse event was pneumonia (n = 2 [11%]). One patient had a dose reduction due to a TEAE of thrombocytopenia. Overall, bortezomib exposure (AUC) in Taiwanese patients (AUC_last [SD]: 230 [147] ng·h/mL) with twice weekly intravenous administration was comparable with non-Asian population (AUC_last [SD]: 241 [82] ng·h/mL). Bortezomib treatment was associated with manageable toxicity profile and did not limit the continuity of therapy.

[Multiple myeloma and venous thrombosis. Which thromboprophylaxis should be given?]

Multiple myeloma is a malignant plasma cells dyscrasia that mainly affects patients older than 65 years. These patients are at a higher risk for venous thromboembolism (VTE) because of cancer status, intrinsic risk factors, and exposure to prothrombotic therapies. The risk for VTE appears higher during the first months of myeloma treatment and decreases over time. Exposure to immunomodulatory drugs (IMIDs) such as thalidomide or lenalidomide in association with high doses of dexamethasone or anthracyclin-based chemotherapy is associated with a four-fold increased risk for VTE. Low-dose aspirin, preventive-dose of low molecular weight heparin (LMWH) or vitamin K antagonists were tested for primary prevention of VTE in myeloma patients receiving chemotherapy. The International Myeloma Working Group (IMWG) suggests stratifying VTE risk to decide which patients should receive VTE prevention. Then, the IMWG suggests giving low-dose aspirin to low VTE risk patients and LMWH or vitamin K antagonists to patients at high risk for VTE. For daily practice, it seems reasonable to start preventive doses of LMWH for 3 to 6 months in ambulatory myeloma patients receiving combined therapy with IMID and in all myeloma patients admitted to hospital.

Clinical outcomes of venous thromboembolism with dalteparin therapy in multiple myeloma patients

This study focused on the clinical outcomes in multiple myeloma (MM) patients with venous thromboembolism (VTE) who received low-molecular-weight heparin (dalteparin) therapy. Changes in D-dimer levels before and after VTE were also evaluated. Among 549 patients treated with various chemotherapeutic agents, a total of 52 (9.47%) patients including 32 newly diagnosed with MM and 16 with relapsed/refractory MM developed VTE, 48 of whom received dalteparin. Among the 48 treated patients, 37 (77%) had proximal deep vein thrombosis (DVT), four had (8%) pulmonary embolism (PE), and seven (15%) had both DVT and PE. In 32 patients with available paired samples (at baseline and VTE occurrence), significant conversion of D-dimer levels from 2.2 ± 0.4 mg/L to 11.8 ± 1.6 mg/L (P < 0.001) was observed, which decreased from 10.9 ± 0.4 mg/L to 1.9 ± 0.6 mg/L one month after initiating dalteparin therapy. A total of 44 patients received dalteparin with a median duration of 4.2 months (range, 2.7-9.4), and four patients were discontinued early due to death (n = 3) and major bleeding (n = 1). After a median follow-up of 9.0 months (range, 0.7-35.8) since the first VTE episode, five patients showed recurrence of VTE with a cumulative incidence of 17.5 ± 7.9%. Major bleeding occurred in three patients. In summary, dalteparin seems to be a promising drug for the treatment of VTE in MM. In addition, the significant difference in D-dimer levels observed before occurrence of VTE and after dalteparin treatment may suggest the usefulness of D-dimer testing as a surrogate marker for VTE in MM patients.

Phase I study of carfilzomib, lenalidomide, vorinostat, and dexamethasone in patients with relapsed and/or refractory multiple myeloma

Research has shown that proteasome inhibitors (e.g., carfilzomib), immunomodulatory agents (e.g., lenalidomide), histone deacetylase inhibitors (e.g., vorinostat) and corticosteroids (e.g., dexamethasone) have synergistic anti-multiple myeloma (MM) activity. This phase I dose-escalation study evaluated a regimen combining carfilzomib, lenalidomide, vorinostat and dexamethasone (QUAD) in patients with relapsed and/or refractory MM. Seventeen patients received carfilzomib (15, 20, or 20/27 mg/m(2) ; 30-min infusion; days 1, 2, 8, 9, 15, 16), lenalidomide (15 or 25 mg; days 1-21), vorinostat (300 or 400 mg; days 1-7, 15-21), and dexamethasone (40 mg; days 1, 8, 15, 22) in 28-d cycles. No dose-limiting toxicities were observed; the maximum tolerated dose was not reached. The maximum administered dose was carfilzomib 20/27 mg/m(2) , lenalidomide 25 mg, vorinostat 400 mg, and dexamethasone 40 mg. Common grade ≥3 adverse events included neutropenia (53%), thrombocytopenia (53%) and anaemia (41%). The overall response rate was 53%: 12% of patients achieved a very good partial response (PR) and 41% of patients achieved a PR. At a median follow-up of 10 months, median progression-free survival was 12 months and median overall survival was not reached. Treatment with QUAD was feasible and had encouraging activity in patients with relapsed and/or refractory MM.

Bortezomib-based therapy for newly diagnosed mantle-cell lymphoma

BACKGROUND

The proteasome inhibitor bortezomib was initially approved for the treatment of relapsed mantle-cell lymphoma. We investigated whether substituting bortezomib for vincristine in frontline therapy with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) could improve outcomes in patients with newly diagnosed mantle-cell lymphoma.

METHODS

In this phase 3 trial, we randomly assigned 487 adults with newly diagnosed mantle-cell lymphoma who were ineligible or not considered for stem-cell transplantation to receive six to eight 21-day cycles of R-CHOP intravenously on day 1 (with prednisone administered orally on days 1 to 5) or VR-CAP (R-CHOP regimen, but replacing vincristine with bortezomib at a dose of 1.3 mg per square meter of body-surface area on days 1, 4, 8, and 11). The primary end point was progression-free survival.

RESULTS

After a median follow-up of 40 months, median progression-free survival (according to independent radiologic review) was 14.4 months in the R-CHOP group versus 24.7 months in the VR-CAP group (hazard ratio favoring the VR-CAP group, 0.63; P<0.001), a relative improvement of 59%. On the basis of investigator assessment, the median durations of progression-free survival were 16.1 months and 30.7 months, respectively (hazard ratio, 0.51; P<0.001), a relative improvement of 96%. Secondary end points were consistently improved in the VR-CAP group, including the complete response rate (42% vs. 53%), the median duration of complete response (18.0 months vs. 42.1 months), the median treatment-free interval (20.5 months vs. 40.6 months), and the 4-year overall survival rate (54% vs. 64%). Rates of neutropenia and thrombocytopenia were higher in the VR-CAP group.

CONCLUSIONS

VR-CAP was more effective than R-CHOP in patients with newly diagnosed mantle-cell lymphoma but at the cost of increased hematologic toxicity. (Funded by Janssen Research and Development and Millennium Pharmaceuticals; LYM-3002 ClinicalTrials.gov number, NCT00722137.).

Clinical use of proteasome inhibitors in the treatment of multiple myeloma

Multiple myeloma (MM) is an incurable hematological malignancy characterized by the clonal proliferation of neoplastic plasma cells. The use of proteasome inhibitors in the treatment of MM has led to significant improvements in outcomes. This article reviews data on the use of the two approved proteasome inhibitors (bortezomib and carlfilzomib), as well as newer agents under development. Emphasis is placed on the clinical use of proteasome inhibitors, including management of side effects and combination with other agents.

Improved response rates with bortezomib in relapsed or refractory multiple myeloma: an observational study in Chinese patients

INTRODUCTION

Bortezomib, a novel proteasome inhibitor, is approved for the treatment of relapsed multiple myeloma (MM). Efficacy and safety of bortezomib is well known; however, it was necessary to validate the data in patients with different ethnic backgrounds. The efficacy and safety of bortezomib was assessed in patients from China with relapsed/refractory MM in a real-world scenario.

METHODS

This prospective, non-interventional, observational study enrolled both male and female Chinese patients, aged ≥18 years and diagnosed with relapsed or refractory MM. Administration of intravenous bortezomib at 1.3 mg/m2 was recommended twice a week for 2 weeks (days 1, 4, 8 and 11), followed by a 10-day rest period (maximum of 8 cycles) and a follow-up every 12 weeks for 3 years. Efficacy assessments included best response, objective response rate (ORR), time to response, duration of response, and overall survival. Safety was also assessed.

RESULTS

A total of 517 patients were enrolled with a median age of 58.7 years. Patients predominantly had immunoglobulin G type (46.2%) and stage III (47.8%) myeloma. Overall, 202 (42.3%) patients had partial response as best response, ORR was 88.9% and the proportion of patients exhibiting complete response was 24.7%. The median time to response observed was 27 (21-40) days. Median time to progression was 415 days and median overall survival was 475 days. Thrombocytopenia (14.4%) was the most common adverse event.

CONCLUSION

Bortezomib demonstrated clinical response in majority of patients and was well tolerated in this observational study in Chinese patients with relapsed/refractory MM.

Phase 1 study of weekly dosing with the investigational oral proteasome inhibitor ixazomib in relapsed/refractory multiple myeloma

Proteasome inhibition is an effective treatment strategy for multiple myeloma. With improving survival, attention is increasingly focusing on ease of administration and toxicity profile. Ixazomib is an investigational, orally bioavailable 20S proteasome inhibitor. Sixty patients with relapsed and/or refractory multiple myeloma were enrolled on this phase 1 trial to evaluate safety and tolerability and determine the maximum tolerated dose (MTD) of single-agent, oral ixazomib given weekly for 3 of 4 weeks. Upon MTD determination, patients were enrolled to 4 different cohorts based on relapsed/refractory status and prior bortezomib and carfilzomib exposure. The MTD was determined to be 2.97 mg/m(2). Dose-limiting toxicities were grade 3 nausea, vomiting, and diarrhea in 2 patients, and grade 3 skin rash in 1 patient. Common drug-related adverse events were thrombocytopenia (43%), diarrhea (38%), nausea (38%), fatigue (37%), and vomiting (35%). The observed rate of peripheral neuropathy was 20%, with only 1 grade 3 event reported. Nine (18%) patients achieved a partial response or better, including 8 of 30 (27%) evaluable patients treated at the MTD. Pharmacokinetic studies suggested a long terminal half-life of 3.6 to 11.3 days, supporting once-weekly dosing. This trial was registered at www.clinicaltrials.gov as #NCT00963820.

Phase 1 study of twice-weekly ixazomib, an oral proteasome inhibitor, in relapsed/refractory multiple myeloma patients

Ixazomib is the first investigational oral proteasome inhibitor to be studied clinically. In this phase 1 trial, 60 patients with relapsed/refractory multiple myeloma (median of 4 prior lines of therapy; bortezomib, lenalidomide, thalidomide, and carfilzomib/marizomib in 88%, 88%, 62%, and 5%, respectively) received single-agent ixazomib 0.24 to 2.23 mg/m(2) (days 1, 4, 8, 11; 21-day cycles). Two dose-limiting toxicities (grade 3 rash; grade 4 thrombocytopenia) occurred at 2.23 mg/m(2). The maximum tolerated dose was 2.0 mg/m(2), which 40 patients received in 4 expansion cohorts. Patients received a median of 4 cycles (range, 1-39); 18% received ≥12 cycles. Eighty-eight percent had drug-related adverse events, including nausea (42%), thrombocytopenia (42%), fatigue (40%), and rash (40%); drug-related grade ≥3 events included thrombocytopenia (37%) and neutropenia (17%). Grade 1/2 drug-related peripheral neuropathy occurred in 12% (no grade ≥3). Two patients died on the study (both considered unrelated to treatment). The terminal half-life of ixazomib was 3.3 to 7.4 days; plasma exposure increased proportionally with dose (0.48-2.23 mg/m(2)). Among 55 response-evaluable patients, 15% achieved partial response or better (76% stable disease or better). These findings have informed the subsequent clinical development of ixazomib in multiple myeloma. This trial was registered at www.clinicaltrials.gov as #NCT00932698.

Proteasome inhibitors in the treatment of multiple myeloma

Proteasome inhibition has been shown to be an effective strategy for the treatment of multiple myeloma, as demonstrated by the clinical activity of the first-in-class agent bortezomib. Recently, the second-generation proteasome inhibitor carfilzomib has been approved in the USA in the relapsed and refractory setting, and several other investigational agents are in clinical development, including MLN9708, marizomib, oprozomib and delanzomib. Here, the authors provide a comprehensive review of the key role of proteasome inhibitors in the myeloma treatment pathway, and highlight the similarities and differences in pharmacology, routes of administration, and efficacy and safety profiles between bortezomib, carfilzomib and investigational agents. The authors also evaluate the potential for further improving myeloma treatment through the ongoing development of novel proteasome inhibitors.

Authorising bortezomib treatment prior to reviewing haematology results: a step toward home administration

Bortezomib treatment requires four visits to a chemotherapy unit in each 21-day cycle. Analysis of the Day 1 full blood count could allow clinicians to predict the risk of Grade 4 thrombocytopenia, thus negating the need to review the full blood count prior to each dose. The freedom to administer bortezomib without reviewing full blood count results on each treatment day could minimise appointment times and be a step toward home administration. A prospective study of treatment authorisation following a full toxicity assessment and full blood count results from the previous treatment day was undertaken. The full blood count results from 27 patients, receiving 381 doses revealed 12 treatment episodes where bortezomib was administered in the presence of Grade 4 thrombocytopenia. One instance of bleeding and two episodes of neutropenic sepsis were detected during toxicity assessments and treatment was not administered. Only one instance of Grade 4 thrombocytopenia was reported on any other treatment day when the Day 1 platelet count was greater than 75 × 10(9) units/l. From this data, Day 1 full blood count parameters were derived, which minimise the risk of Grade 4 haematological toxicity on subsequent treatment days, allowing clinicians to identify suitable patients for administration of bortezomib prior to reviewing full blood count results. When platelet counts on Day 1 are greater than 75 × 10(9) units/l and neutrophil counts are greater than 1.0 × 10(9) units/l, the administration of bortezomib can be authorised without the need for review of the full blood count on subsequent days of that cycle.

Bortezomib for the treatment of previously untreated multiple myeloma

Management of multiple myeloma (MM) has been drastically changed in the last 10 years thanks to the introduction of novel agents, which, combined with the backbone of classical chemotherapy, have led to a significant improvement in disease control. Bortezomib is the first reversible proteasome inhibitor approved for the treatment of MM, with wide synergism in vitro and in vivo with a plethora of drugs active for MM. In patients eligible for autologous stem cell transplantation (ASCT), the achievement of complete response or very good partial response before ASCT is associated with prolonged progression-free and overall survival. Thus, the goal of induction regimens should include, at least for younger patients, a continued improvement of the quality and depth of the achieved response. This article is focused on reviewing the major efforts in frontline therapy for MM, including bortezomib-containing induction regimens in patients either eligible or ineligible for ASCT.

An historic perspective of proteasome inhibition

The ubiquitin-proteasome system (UPS) and associated signaling pathways are regarded today as an exciting area of development for novel therapeutics. However, two decades ago, following the discovery and elucidation of ubiquitin and the 26S proteasome as key mediators of protein turnover, the concept of inhibiting the UPS was not even considered a feasible therapeutic approach due to the assumption that inhibition of this pathway would have widespread deleterious effects. Subsequent clinical developments with the first-in-class proteasome inhibitor bortezomib have radically overturned that view, with the proteasome now recognized as a validated target and proteasome inhibition demonstrated to be a highly successful treatment for a number of hematologic malignancies. Here we provide a historic perspective on the emergence of proteasome inhibition, sharing some of the lessons learned along the way. We describe the development of bortezomib and the elucidation of the effects of its novel mechanism of action, and place the cutting-edge work described elsewhere in this issue in the context of these historic developments.

How to maintain patients on long-term therapy: understanding the profile and kinetics of adverse events

Thalidomide, lenalidomide, and bortezomib have considerably improved the survival of patients with multiple myeloma. These agents have specific adverse event (AE) profiles, and it is especially important to consider severe AEs that may lead to premature discontinuation, negatively affecting outcomes. AEs of particular concern are peripheral neuropathy (associated with thalidomide and bortezomib), venous thromboembolism (associated with thalidomide and lenalidomide), and myelosuppression (associated with lenalidomide and bortezomib). AEs are usually predictable and easily managed with monitoring, appropriate dose adjustments, and supportive care. AEs are generally transient, occurring early in the course of treatment, providing evidence for the feasibility of continuous therapy.

A prospective, international phase 2 study of bortezomib retreatment in patients with relapsed multiple myeloma

Multiple myeloma (MM) typically follows a relapsing course with many patients requiring multiple therapies. This single-arm phase 2 study prospectively evaluated the efficacy and safety of bortezomib retreatment in MM patients who had relapsed after achieving at least a partial response (≥ PR) to prior bortezomib-based therapy. Patients aged ≥ 18 years, with measurable, secretory MM, who relapsed ≥ 6 months after prior bortezomib treatment were eligible. Patients received up to eight cycles of bortezomib (± dexamethasone). The primary endpoint was best confirmed response at retreatment; secondary endpoints included duration of response (DOR), time to progression (TTP), and safety. Adverse events (AEs) were graded by National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. A total of 130 patients (median of two prior lines of therapy) were enrolled and received retreatment. At retreatment, 28% and 72% of patients received bortezomib and bortezomib-dexamethasone, respectively. Overall response rate was 40%. In patients who achieved ≥ PR, median DOR and TTP were 6.5 and 8.4 months, respectively. Thrombocytopenia was the most common grade ≥ 3 AE (35%). Forty percent of patients experienced neuropathy events, which improved and resolved in a median of 1.5 and 8.9 months, respectively. In conclusion, bortezomib retreatment was effective and tolerable in relapsed MM patients, with no evidence of cumulative toxicities.

Risk and management of thrombosis in multiple myeloma

Patients diagnosed with multiple myeloma have an increased risk of venous thrombosis. This may be due to various risk factors, including disease specific factors, changes in coagulation and fibrinolysis factors and circulating prothrombotic microparticles. More recent studies have indicated that also arterial thrombosis, including acute myocardial infarction and stroke do occur more frequently in these patients. Studies on etiological factors contributing to the development of thrombosis will be reviewed in this article. In addition we will focus on the prevention and management of arterial and venous thrombosis in patients with multiple myeloma.

Thrombosis in hematologic malignancies: risks and consequences

SUMMARY Thrombotic complications in hematologic malignancies have been found to be high among the various forms of cancer. Thrombosis not only increases the morbidity, but also has an adverse impact on survival. The pathogenesis among the different forms of hematologic malignancies is reviewed in this article. The thrombogenicity of the individual malignant cells, the tumor burden, treatment modalities and presence of comorbidities are among the major risk factors. These factors vary with the acute leukemias, lymphomas, multiple myeloma and myeloproliferative neoplasms. The thrombogenetic factors in the more common hematologic malignancies are discussed. Results of recent randomized controlled clinical trials are beginning to provide data for meaningful therapeutic guidelines on thromboprophylaxis. They also enable the clinician to assess the risk factors in each individual patient. More clinical trials are needed to provide better risk stratification and to devise risk-adapted treatment regimens.

Lenalidomide for the treatment of relapsed and refractory multiple myeloma

Lenalidomide is an amino-substituted derivative of thalidomide with direct antiproliferative and cytotoxic effects on the myeloma tumor cell, as well as antiangiogenic activity and immunomodulatory effects. Together with the introduction of bortezomib and thalidomide, lenalidomide has significantly improved the survival of patients with relapsed and refractory myeloma. The most common adverse events associated with lenalidomide include fatigue, skin rash, thrombocytopenia, and neutropenia. In addition, when lenalidomide is combined with dexamethasone or other conventional cytotoxic agents, there is an increase in the incidence of venous thromboembolic events. There is now evidence that continued treatment with lenalidomide has a significant impact on survival by improving the depth and duration of response. This highlights the value of adverse event management and appropriate dose adjustments to prevent toxicity, and of allowing continued treatment until disease progression. In this review, we will discuss the different lenalidomide-based treatment regimens for patients with relapsed/refractory myeloma. This is accompanied by recommendations of how to manage and prevent adverse events associated with lenalidomide-based therapy.

Perifosine plus bortezomib and dexamethasone in patients with relapsed/refractory multiple myeloma previously treated with bortezomib: results of a multicenter phase I/II trial

PURPOSE

Novel agents have improved patient outcome in relapsed or relapsed/refractory multiple myeloma (MM). Preclinical data show that the novel signal transduction modulator, perifosine, enhances the cytotoxicity of dexamethasone and bortezomib. Clinical data suggest that perifosine in combination with dexamethasone has activity in relapsed or relapsed/refractory MM.

PATIENTS AND METHODS

In a phase I/II study, perifosine in combination with bortezomib with or without dexamethasone was prospectively evaluated in 84 patients with relapsed or relapsed/refractory MM. All were heavily pretreated and bortezomib exposed; 73% were refractory to bortezomib, and 51% were refractory to bortezomib and dexamethasone. The dose selected for the phase II study was perifosine 50 mg/d plus bortezomib 1.3 mg/m(2), with the addition of low-dose dexamethasone at 20 mg if progression occurred on perifosine plus bortezomib alone.

RESULTS

An overall response rate (ORR; defined as minimal response or better) of 41% was demonstrated with this combination in 73 evaluable patients, including an ORR of 65% in bortezomib-relapsed patients and 32% in bortezomib-refractory patients. Therapy was generally well tolerated; toxicities, including gastrointestinal adverse effects and fatigue, proved manageable. No treatment-related mortality was seen. Median progression-free survival was 6.4 months, with a median overall survival of 25 months (22.5 months in bortezomib-refractory patients).

CONCLUSION

Perifosine-bortezomib ± dexamethasone demonstrated encouraging activity in heavily pretreated bortezomib-exposed patients with advanced MM. A phase III trial is underway comparing perifosine-bortezomib plus dexamethasone with bortezomib-dexamethasone in patients with relapsed/refractory MM previously treated with bortezomib.

Treatment options for relapsed and refractory multiple myeloma

Treatment options for patients with relapsed myeloma have benefited from the development of new targeted agents. The use of bortezomib, thalidomide, and lenalidomide have dramatically changed outcomes for patients with relapsed myeloma. New agents are also in development, on the basis of preclinical rationale, as well as combinations of conventional and novel agents. Together each of these treatment approaches are being tested in phase I, II, and III clinical trials, with the goal of prolonged duration of remission and, ultimately, improved overall survival.

Tanespimycin and bortezomib combination treatment in patients with relapsed or relapsed and refractory multiple myeloma: results of a phase 1/2 study

This open-label, dose escalation, multicentre phase 1/2 trial was undertaken to determine the safety and tolerability of the heat shock protein 90 (HSP90) inhibitor tanespimycin (100-340 mg/m(2) )+ bortezomib (0·7-1·3 mg/m(2) ) given on days 1, 4, 8 and 11 in each 21-d cycle. Phase 2 expansion occurred at the highest tested dose of tanespimycin at 340 mg/m(2) and bortezomib at 1·3 mg/m(2) . Seventy-two patients (median age, 60 years) with relapsed or relapsed and refractory multiple myeloma (MM) were enrolled; 63 patients (89%) completed the study. Tanespimycin in combination with bortezomib was well tolerated; few patients experienced significant neutropenia, constipation and anorexia (<10%), and no patients developed severe peripheral neuropathy. Among 67 efficacy-evaluable patients, there were 2 (3%) complete responses and 8 (12%) partial responses, for an objective response rate (ORR) of 27%, including 8 (12%) minimal responses. Response rates were highest among bortezomib-naive patients and proved durable in all patient subgroups, including those with bortezomib-refractory disease. Pharmacodynamic analyses indicated that tanespimycin plus bortezomib effectively inhibited the proteasome, as evidenced by decreased 20S proteasome activity, and inhibited HSP90, as reflected by increased HSP70 expression. The results of this study support additional studies of this combination approach in MM.

Practical management of adverse events in multiple myeloma: can therapy be attenuated in older patients?

The current standard of care for elderly patients with newly diagnosed multiple myeloma is melphalan and prednisone (MP) in combination with either bortezomib (VMP) or thalidomide (MPT), with lenalidomide plus dexamethasone increasingly being employed. The addition of bortezomib or thalidomide to the established MP regimen significantly improves outcomes and prolongs survival in elderly and transplant-ineligible patients. However, these benefits are accompanied by increases in treatment-related adverse events (AEs), which may be particularly pronounced in older individuals. Patients receiving bortezomib as part of a VMP regimen commonly experience transient and cyclical thrombocytopenia and neutropenia, along with gastrointestinal AEs. Fortunately, these AEs can be managed with appropriate supportive care and, when necessary, adjustments in dose. Peripheral neuropathy (PN) is the most important side effect of bortezomib, and although it is reversible in a high proportion of patients, it affects their quality of life. Furthermore, PN can require temporary or permanent withholding of bortezomib, which will reduce treatment efficacy. PN is also a common adverse effect of thalidomide; thromboembolic events are also a key concern, requiring thromboprophylaxis in patients receiving thalidomide in combination. For lenalidomide in combination with dexamethasone, the most clinically important adverse effects are hematologic toxicity (particularly neutropenia) and thromboembolic events. Recent phase III studies in newly diagnosed elderly patients are providing further insight into the most appropriate treatment regimens to maximize outcomes and minimize toxicity in individual patients. Of note, once-weekly bortezomib dosing (in combination with MP±T) was shown to reduce the incidence of peripheral neuropathy and gastrointestinal events compared with twice-weekly dosing, while maintaining efficacy. Elderly patients may be less able to withstand the AEs associated with newer treatment regimens and combinations of multiple drugs, and may experience greater declines in quality of life and, subsequently, reduced treatment adherence. It is therefore critical that these patients are closely monitored and any emergent AEs promptly and appropriately managed. For very elderly, frail patients, tailored therapy, reduced intensity regimens, and adverse event management are necessary to encourage treatment adherence and reduce discontinuation. This article will provide practical guidance on the management of bortezomib-, thalidomide-, and lenalidomide-associated AEs, to maximize treatment feasibility and active drug delivered, and thus help minimize toxicity and maximize outcomes.

Low venous thromboembolic risk with bortezomib in multiple myeloma and potential protective effect with thalidomide/lenalidomide-based therapy: review of data from phase 3 trials and studies of novel combination regimens

Patients with multiple myeloma (MM) are at elevated risk of venous thromboembolism (VTE), specifically deep vein thrombosis (DVT) and pulmonary embolism (PE). VTE risk in MM is increased by various patient- and disease-related factors. The type of anti-MM therapy represents a key factor, with a substantially elevated VTE risk in patients treated with the immunomodulatory drugs (IMiDs) thalidomide or lenalidomide in combination with dexamethasone and/or chemotherapy; VTE risk with lenalidomide-dexamethasone is further increased with concomitant erythropoietin. By contrast, treatment with the proteasome inhibitor bortezomib, alone or in combination, does not increase VTE risk; rates of DVT/PE do not appear affected by the use of erythropoiesis-stimulating agents. Bortezomib has shown antihemostatic effects in patients with relapsed or refractory MM, which supports that it exerts antithrombotic actions and thus potentially provides a protective effect in combination with regimens with an elevated VTE risk. Herein, we review data from phase 3 trials of bortezomib- and/or IMiD-based therapy in frontline MM, together with other studies of novel combination regimens. Despite the confounding effect of variable VTE prophylaxis, bortezomib-based regimens were typically associated with DVT/PE rates of ≤5%, similar to those seen with melphalan-prednisone and dexamethasone, whereas IMiD-based bortezomib-free regimens were generally associated with higher rates. Direct comparisons of regimens of thrombogenic potential with or without bortezomib demonstrated lower VTE risk with bortezomib. Between-study comparisons of VTE risk support these findings. Taken together, these data confirm the low VTE risk associated with bortezomib and support a potential protective effect of bortezomib in combination with IMiD-based regimens associated with elevated VTE risk.

Characterization of haematological parameters with bortezomib-melphalan-prednisone versus melphalan-prednisone in newly diagnosed myeloma, with evaluation of long-term outcomes and risk of thromboembolic events with use of erythropoiesis-stimulating agents: analysis of the VISTA trial

Although haematological toxicities, such as anaemia, are common in multiple myeloma (MM), no clear consensus exists on the use and impact of erythropoiesis-stimulating agents (ESA) on outcomes in MM. This analysis characterizes haematological toxicities and associated interventions in the phase III VISTA (Velcade(®) as Initial Standard Therapy in Multiple Myeloma: Assessment with Melphalan and Prednisone) study of bortezomib plus melphalan/prednisone (VMP, n = 344) versus MP (n = 338) in previously untreated MM patients ineligible for high-dose therapy, and evaluates the impact of ESA use or red-blood-cell (RBC) transfusions on outcomes and thromboembolic risk. Incidence of haematological toxicities was similar with VMP and MP; similar rates of interventions and associated complications (e.g. bleeding, febrile neutropenia) were observed. Two hundred thirty three patients received ESA; 204 had RBC transfusions. Frequency of thromboembolic events was low and not affected by ESA use. Median time-to progression (TTP) was similar between ESA/non-ESA [hazard ratio: 1·03 (95% confidence interval 0·76-1·39); P = 0·8478] in both arms (VMP: 19·9/not reached; MP: 15·0/17·5 months). Three-year overall survival (OS) rates were similar between ESA/non-ESA in each arm. Patients receiving RBC transfusions had significantly shorter OS (P < 0·0001) versus non-RBC-transfusion patients. In conclusion, bortezomib did not add to melphalan haematological toxicity. Concomitant ESA use with VMP/MP in previously untreated MM patients did not adversely affect TTP or OS, or increase thromboembolic risk. However, RBC transfusion was associated with significantly shorter survival.

The efficacy and safety of bortezomib and dexamethasone as a maintenance therapy in patients with advanced multiple myeloma who are responsive to salvage bortezomib-containing regimens

BACKGROUND

Although treatment for multiple myeloma (MM) has considerably improved in the past decade, MM continues to be an incurable hematological malignancy that causes most patients to eventually relapse and die from their illness. Thus, the identification of effective salvage strategies remains a priority.

METHODS

In this trial, the authors evaluated the safety and efficacy of bortezomib and dexamethasone [V: on days 1 and 15 (1.3 mg/mq); D: on days 1-2 and 15-16, every 28-day cycle until progression (20 mg/d)] as maintenance therapy (MT) in patients with advanced MM who responded to salvage therapy that used a bortezomib-containing regimen.

RESULTS

Forty-nine MM patients were enrolled in this study between October of 2004 and April of 2008. All patients who were included in this study were responsive to a prior salvage therapy with bortezomib and had a measurable disease. The bortezomib and dexamethasone MT improved the quality of responses to complete remission in 4 patients and very good partial response in 3 patients. In addition, 10 patients experienced at least a 50% improvement in their symptoms. The median time to progression (TTP) was 16 months with a progression-free survival of 61% after 1 year. The overall response after 1 year was 76%, and the cumulative incidence of death due to disease progression, which was adjusted for competitive risk events, was 14%. Non-dose-limiting toxicities included neuropathy (predominantly grade 1), herpes zoster reactivation, pneumonia, and gastrointestinal affections (constipation and diarrhea). Three patients developed grade 2 neuropathy, which required a bortezomib dose reduction to 1.0 mg/mq. No grade 3 or 4 toxicities were recorded.

CONCLUSIONS

The use of bortezomib and dexamethasone as MT in advanced MM was effective and well tolerated. The twice-monthly bortezomib infusion appeared to reduce the incidence of grade 3 and 4 neuropathies in comparison to similar experiences in other settings.