Bortezomib, melphalan, and prednisone versus bortezomib, thalidomide, and prednisone as induction therapy followed by maintenance treatment with bortezomib and thalidomide versus bortezomib and prednisone in elderly patients with untreated multiple myeloma: a randomised trial

Multiple myeloma: 2014 Update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Multiple myeloma accounts for approximately 10% of hematologic malignancies.

DIAGNOSIS

The diagnosis requires 10% or more clonal plasma cells on bone marrow examination or a biopsy proven plasmacytoma plus evidence of associated end-organ damage. If end-organ damage is not present, the presence of 60% or more clonal plasma cells in the marrow is also considered as myeloma.

RISK STRATIFICATION

In the absence of concurrent trisomies, patients with 17p deletion, t(14;16), and t(14;20) are considered to have high-risk myeloma. Patients with t(4;14) translocation are considered intermediate-risk. All others are considered as standard-risk. Risk-adapted initial therapy: Standard-risk patients can be treated with lenalidomide plus low-dose dexamethasone (Rd), or a bortezomib-containing triplet such as bortezomib, cyclophosphamide, dexamethasone (VCD). Intermediate-risk and high-risk patients require a bortezomib-based triplet regimen. In eligible patients, initial therapy is given for approximately 4 months followed by autologous stem cell transplantation (ASCT). Standard risk patients can opt for delayed ASCT if stem cells can be cryopreserved. In patients who are not candidates for transplant, initial therapy is given for approximately 12 to 18 months. Maintenance therapy: After initial therapy, lenalidomide maintenance is considered for standard risk patients who are not in very good partial response or better, while maintenance with a bortezomib-based regimen should be considered in patients with intermediate or high risk myeloma. Management of refractory disease: Patients with indolent relapse can be treated first with 2-drug or 3-drug combinations. Patients with more aggressive relapse often require therapy with a combination of multiple active agents.

Lenalidomide and dexamethasone in transplant-ineligible patients with myeloma

BACKGROUND

The combination melphalan-prednisone-thalidomide (MPT) is considered a standard therapy for patients with myeloma who are ineligible for stem-cell transplantation. However, emerging data on the use of lenalidomide and low-dose dexamethasone warrant a prospective comparison of the two approaches.

METHODS

We randomly assigned 1623 patients to lenalidomide and dexamethasone in 28-day cycles until disease progression (535 patients), to the same combination for 72 weeks (18 cycles; 541 patients), or to MPT for 72 weeks (547 patients). The primary end point was progression-free survival with continuous lenalidomide-dexamethasone versus MPT.

RESULTS

The median progression-free survival was 25.5 months with continuous lenalidomide-dexamethasone, 20.7 months with 18 cycles of lenalidomide-dexamethasone, and 21.2 months with MPT (hazard ratio for the risk of progression or death, 0.72 for continuous lenalidomide-dexamethasone vs. MPT and 0.70 for continuous lenalidomide-dexamethasone vs. 18 cycles of lenalidomide-dexamethasone; P<0.001 for both comparisons). Continuous lenalidomide-dexamethasone was superior to MPT for all secondary efficacy end points, including overall survival (at the interim analysis). Overall survival at 4 years was 59% with continuous lenalidomide-dexamethasone, 56% with 18 cycles of lenalidomide-dexamethasone, and 51% with MPT. Grade 3 or 4 adverse events were somewhat less frequent with continuous lenalidomide-dexamethasone than with MPT (70% vs. 78%). As compared with MPT, continuous lenalidomide-dexamethasone was associated with fewer hematologic and neurologic toxic events, a moderate increase in infections, and fewer second primary hematologic cancers.

CONCLUSIONS

As compared with MPT, continuous lenalidomide-dexamethasone given until disease progression was associated with a significant improvement in progression-free survival, with an overall survival benefit at the interim analysis, among patients with newly diagnosed multiple myeloma who were ineligible for stem-cell transplantation. (Funded by Intergroupe, Francophone du Myélome and Celgene; FIRST ClinicalTrials.gov number, NCT00689936; European Union Drug Regulating Authorities Clinical Trials number, 2007-004823-39.).

Therapeutic advancements in multiple myeloma

Multiple myeloma survival has significantly improved in the latest years due to a broad spectrum of novel agents available for treatment. The introduction of thalidomide, bortezomib, and lenalidomide together with autologous stem-cell transplantation has considerably increased complete remission rate and progression-free survival resulting ultimately in prolonged survival in myeloma patients. Moreover, novel strategies of treatment such as consolidation and maintenance are being used to further implement responses. Finally, a number of new drugs such as carfilzomib and pomalidomide are already in clinical practice, making the future of myeloma patients brighter.

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.

Bortezomib in multiple myeloma: systematic review and clinical considerations

We conducted a systematic review to determine the appropriate use of bortezomib alone or in combination with other agents in patients with multiple myeloma (mm). We searched medline, embase, the Cochrane Library, conference proceedings, and the reference lists of included studies. We analyzed randomized controlled trials and systematic reviews if they involved adult mm patients treated with bortezomib and if they reported on survival, disease control, response, quality of life, or adverse effects. Twenty-six unique studies met the inclusion criteria. For patients with previously untreated mm and for candidates for transplantation, we found a statistically significant benefit in time to progression [hazard ratio (hr): 0.48, p < 0.001; and hr: 0.63, p = 0.006, respectively] and a better response with a bortezomib than with a non-bortezomib regimen (p < 0.001). Progression-free survival was longer with bortezomib and thalidomide than with thalidomide alone (p = 0.01). In non-candidates for transplantation, a significant benefit in overall survival was observed with a bortezomib regimen (hr compared with a non-bortezomib regimen: 0.61; p = 0.008), and in transplantation candidates receiving bortezomib, the response rate was improved after induction (p = 0.004) and after a first transplant (p = 0.016). In relapsed or refractory mm, overall survival (p = 0.03), time to progression (hr: 1.82; p = 0.000004), and progression-free survival (hr: 1.69; p = 0.000026) were significantly improved with bortezomib and pegylated liposomal doxorubicin (compared with bortezomib alone), and bortezomib monotherapy was better than dexamethasone alone (hr: 0.77; p = 0.027). Bortezomib combined with thalidomide and dexamethasone was better than either bortezomib monotherapy or thalidomide with dexamethasone (p < 0.001). In previously untreated or in relapsed or refractory mm patients, bortezomib-based therapy has improved disease control and, in some patients, overall survival.

SMART designs in cancer research: Past, present, and future

BACKGROUND

Cancer affects millions of people worldwide each year. Patients require sequences of treatment based on their response to previous treatments to combat cancer and fight metastases. Physicians provide treatment based on clinical characteristics, changing over time. Guidelines for these individualized sequences of treatments are known as dynamic treatment regimens (DTRs) where the initial treatment and subsequent modifications depend on the response to previous treatments, disease progression, and other patient characteristics or behaviors. To provide evidence-based DTRs, the Sequential Multiple Assignment Randomized Trial (SMART) has emerged over the past few decades.

PURPOSE

To examine and learn from past SMARTs investigating cancer treatment options, to discuss potential limitations preventing the widespread use of SMARTs in cancer research, and to describe courses of action to increase the implementation of SMARTs and collaboration between statisticians and clinicians.

CONCLUSION

There have been SMARTs investigating treatment questions in areas of cancer, but the novelty and perceived complexity has limited its use. By building bridges between statisticians and clinicians, clarifying research objectives, and furthering methods work, there should be an increase in SMARTs addressing relevant cancer treatment questions. Within any area of cancer, SMARTs develop DTRs that can guide treatment decisions over the disease history and improve patient outcomes.

Estimation of optimal dynamic treatment regimes

BACKGROUND

Recent advances in medical research suggest that the optimal treatment rules should be adaptive to patients over time. This has led to an increasing interest in studying dynamic treatment regime, a sequence of individualized treatment rules, one per stage of clinical intervention, which maps present patient information to a recommended treatment. There has been a recent surge of statistical work for estimating optimal dynamic treatment regimes from randomized and observational studies. The purpose of this article is to review recent methodological progress and applied issues associated with estimating optimal dynamic treatment regimes.

METHODS

We discuss sequential multiple assignment randomized trials, a clinical trial design used to study treatment sequences. We use a common estimator of an optimal dynamic treatment regime that applies to sequential multiple assignment randomized trials data as a platform to discuss several practical and methodological issues.

RESULTS

We provide a limited survey of practical issues associated with modeling sequential multiple assignment randomized trials data. We review some existing estimators of optimal dynamic treatment regimes and discuss practical issues associated with these methods including model building, missing data, statistical inference, and choosing an outcome when only non-responders are re-randomized. We mainly focus on the estimation and inference of dynamic treatment regimes using sequential multiple assignment randomized trials data. Dynamic treatment regimes can also be constructed from observational data, which may be easier to obtain in practice; however, care must be taken to account for potential confounding.

Subcutaneous bortezomib for multiple myeloma treatment: patients' benefits

The use of novel agents such as thalidomide, lenalidomide, and bortezomib has considerably improved the outcome of multiple myeloma patients. Besides greater biological activity, these drugs unfortunately have also been associated with greater toxicity. To evaluate the positive effect on the quality of life of patients, driven by both the tolerability and antimyeloma activity of bortezomib, we analyzed data that have been published concerning different strategies used to improve its tolerability as once weekly and/or subcutaneous administration.

Novel agents and new therapeutic approaches for treatment of multiple myeloma

This review summarizes the therapeutic strategies and the drugs actually in development for the management of myeloma patients. Multiple myeloma is caused by the expansion of monoclonal plasma cells and secretion of M-protein (immunoglobulins, Bence Jones protein and free light chains). Multiple myeloma still remains an incurable disease with a high incidence rate in the elderly, despite the introduction of several new therapeutic agents (bortezomib, lenalidomide and thalidomide) which have changed its natural history. The high heterogeneity of this disease leads to large differences in clinical responses to treatments. Thus, the choice of the best treatment is a difficult issue. However, the introduction of new drugs has made it possible to achieve high response rates and good quality responses with long-term disease control. Interactions between tumor cells and their bone marrow microenvironment play a pivotal role in the development, maintenance, and progression of myeloma, inducing also drug resistance. These knowledges have improved treatment options, leading to the approval of new drugs which not only target the malignant cell itself, but also its microenvironment. These agents are in preclinical/early clinical evaluation and they appear to further improve disease control, but their use is still not approved outside of clinical trials.

Inference about the expected performance of a data-driven dynamic treatment regime

BACKGROUND

A dynamic treatment regime (DTR) comprises a sequence of decision rules, one per stage of intervention, that recommends how to individualize treatment to patients based on evolving treatment and covariate history. These regimes are useful for managing chronic disorders, and fit into the larger paradigm of personalized medicine. The Value of a DTR is the expected outcome when the DTR is used to assign treatments to a population of interest.

PURPOSE

The Value of a data-driven DTR, estimated using data from a Sequential Multiple Assignment Randomized Trial, is both a data-dependent parameter and a non-smooth function of the underlying generative distribution. These features introduce additional variability that is not accounted for by standard methods for conducting statistical inference, for example, the bootstrap or normal approximations, if applied without adjustment. Our purpose is to provide a feasible method for constructing valid confidence intervals (CIs) for this quantity of practical interest.

METHODS

We propose a conceptually simple and computationally feasible method for constructing valid CIs for the Value of an estimated DTR based on subsampling. The method is self-tuning by virtue of an approach called the double bootstrap. We demonstrate the proposed method using a series of simulated experiments.

RESULTS

The proposed method offers considerable improvement in terms of coverage rates of the CIs over the standard bootstrap approach.

LIMITATIONS

In this article, we have restricted our attention to Q-learning for estimating the optimal DTR. However, other methods can be employed for this purpose; to keep the discussion focused, we have not explored these alternatives.

CONCLUSION

Subsampling-based CIs provide much better performance compared to standard bootstrap for the Value of an estimated DTR.

Advances in multiple myeloma therapy during two past decades

Multiple myeloma (MM) is a clonal B-cell malignancy characterized by aberrant expansion of plasma cells within bone marrow and extramedullary sites. It is one of the most common haematological malignancies; it accounts for 1.4% of all tumours and is responsible for 2% of cancer-related mortality. Over the last decades, the paradigm of MM therapy has changed dramatically - from the conventional combination of oral melphatan + prednisone, high-dose chemotherapy with stem cell (ASCT) support for younger patients to the present paradigm with the use of one (or more) of 3 major new targeted agents - the first-in class proteasome inhibitor bortezomib, the immunomodulatory drug thalidomide, and its more potent derivative lenalidomide. Their use as a part of initial therapy is associated with high overall response rates as well as high rates of complete response (CR), both for elderly patients unable to undergo ASCT and for younger patients treated prior to ASCT. Altogether, the advent of novel agents has resulted in a 50% improvement in median survival. Moreover, the development of new drug classes based on preclinical rationale and the introduction of next-generation agents are likely to further expand treatment options and improve outcomes for especially relapsed MM. This review highlights important historic landmarks as well as more recent events that have played an important role in the evolution of myeloma targeted therapy.

The choice of regimens based on bortezomib for patients with newly diagnosed multiple myeloma

Introduction

Bortezomib has significantly improved multiple myeloma (MM) response rates, but strategies for choosing bortezomib-based regimens for initial MM therapy are not standardized. Here, we describe four bortezomib-based therapies in Chinese MM patients to determine the optimal chemotherapeutic approach.

Methods

Newly diagnosed symptomatic MM patients at three hematological centers between February 1, 2006 and May 31, 2013 were treated with therapies including bortezomib plus dexamethasone (PD) or combinations of PD with either adriamycin (PAD), cyclophosphamide (PCD) or thalidomide (PTD) for every 28 days.

Results

The overall response rate of all the 215 eligible patients was 90.2%. The ORR for PCD, PAD, PTD and PD were 97.4%, 93.2%, 85.3% and 77.8% while the effects with VGPR or better were 63.7%, 62.7%, 44.2% and 37.8%, respectively. The effect of ORR, VGPR and CR/nCR for the PCD regimen was better than the PD protocol. Median PFS for all patients was 29.0 months with significant differences observed among treatment groups. Median OS of all the patients was not reached, but three-drug combinations were superior to PD alone. Frequently observed toxicities were neutropenia, thrombocytopenia, fatigue, infection, herpes zoster, and peripheral neuropathy. The incidence of peripheral neuropathy (PN) in PTD group was significantly higher than other three groups, especially grade 2–3 PN. Treatment with anti-viral agent acyclovir significantly reduced the incidence of herpes zoster.

Conclusions

Our experience indicated that bortezomib-based regimens were effective and well-tolerated in the Chinese population studied; three-drug combinations PCD, PAD were superior to PD, especially with respect to PCD.

The future of autologous stem cell transplantation in myeloma

Autologous stem cell transplantation (ASCT) has long been considered frontline therapy for newly diagnosed myeloma patients. This Spotlight examines the role of ASCT in the era of novel drugs and argues that ASCT should continue to be considered for eligible patients. A combination of novel drugs with ASCT in a sequential treatment approach can attain long-term survival and perhaps cure a subset of patients. ASCT will likely remain an important platform to develop curative strategies in the foreseeable future.

Incorporating novel agents in the management of elderly myeloma patients

In recent years, the treatment of multiple myeloma has undergone significant changes. The availability of novel agents bortezomib, thalidomide and lenalidomide considerably improved the outcome of patients. The advantages related to the use of novel agents have been shown in various studies in patients eligible and ineligible for transplant. In elderly patients, novel agents have also revolutionized the treatment paradigm and have replaced the traditional melphalan-prednisone regimen. A sequential approach consisting of an induction regimen associated with a high rate of complete response, followed by consolidation/maintenance therapy, induces a profound cytoreduction and delays relapse, thus improving survival. Patients older than 75 years or who are otherwise vulnerable are more susceptible to adverse events. In this setting, less toxic regimens and appropriate dose-reductions should be adopted. This article provides an overview of the main trials for transplant-ineligible multiple myeloma patients. Recommendations on how to manage unfit patients and treatment-related toxicities are also provided.

Bortezomib cumulative dose, efficacy, and tolerability with three different bortezomib-melphalan-prednisone regimens in previously untreated myeloma patients ineligible for high-dose therapy

Substantial efficacy has been demonstrated with bortezomib-melphalan-prednisone in phase III studies in transplant-ineligible myeloma patients using various twice-weekly and once-weekly bortezomib dosing schedules. In VISTA, the regimen comprised four 6-week twice-weekly cycles, plus five 6-week once-weekly cycles. In the GIMEMA MM-03-05 study, the bortezomib-melphalan-prednisone regimen was either per VISTA ('GIMEMA twice-weekly'), or comprised nine 5-week once-weekly cycles ('GIMEMA once-weekly'). In the GEM2005MAS65 study, the regimen comprised one 6-week twice-weekly cycle, plus five 5-week once-weekly cycles. We evaluated the cumulative bortezomib dose administered during bortezomib-melphalan-prednisone, as well as efficacy and tolerability, using patient-level study data. Over all bortezomib-melphalan-prednisone cycles (nine in VISTA/GIMEMA; six in GEM2005MAS65), the median cumulative bortezomib dose administered was 38.5, 42.1, 40.3, and 32.9 mg/m(2) in VISTA, GIMEMA twice-weekly, GIMEMA once-weekly, and GEM2005MAS65, respectively, and the respective proportions of planned bortezomib dose actually delivered were 57.0%, 62.3%, 86.1%, and 90.4%. Response rates following bortezomib-melphalan-prednisone were 74-87% and appeared generally similar between studies. Three-year survival rates were 67.9-75.7% across studies. Grade 3/4 peripheral neuropathy rates were 13% in VISTA and 14% in GIMEMA twice-weekly, but were lower at 2% in GIMEMA once-weekly and 7% in GEM2005MAS65. Discontinuations and bortezomib dose reductions due to peripheral neuropathy were reduced in GIMEMA once-weekly versus VISTA and GIMEMA twice-weekly. Exclusive or predominant use of once-weekly bortezomib dosing in GIMEMA once-weekly and GEM2005MAS65 resulted in high efficacy, comparable with that demonstrated in VISTA, and similar cumulative bortezomib dose with reduced toxicity. Trials are registered with ClinicalTrials.gov: VISTA (Identifier:00111319), GIMEMA MM-03-05 (Identifier:01063179), and GEM2005MAS65 (Identifier:00443235).

Bortezomib, melphalan, prednisone (VMP) versus melphalan, prednisone, thalidomide (MPT) in elderly newly diagnosed multiple myeloma patients: A retrospective case-matched study

Novel agents in combination with melphalan and prednisone (MP) significantly improved progression-free survival (PFS) and overall survival (OS) in multiple myeloma (MM). Randomized trials comparing MP plus bortezomib (VMP) versus MP plus thalidomide (MPT) are lacking. Nine hundred and fifty-six elderly (>65 years) newly diagnosed MM patients from six European randomized trials were retrospectively analyzed and matched for age, albumin, and beta2-microglobulin at diagnosis, 296 patients were selected from the VMP groups, and 294 from MPT. Complete response rate was 21% in the VMP patients and 13% in the MPT patients (P = 0.007). After a median follow-up of 34 months (range, 1-92), VMP significantly prolonged both PFS (median 32.5 vs. 22.9 months, HR 0.65; 95% CI 0.52-0.82; P < 0.001) and OS (median 79.7 vs. 45.1 months, HR 0.44; 95% CI 0.32-0.59; P < 0.001) in comparison with MPT. The benefit in terms of OS of the VMP group was quite similar among patients with different risk factors defined by sex, ISS, ECOG performance status, or serum creatinine but not among patients ≥ 75 years. Multivariate analysis confirmed that VMP was an independent predictor of longer PFS and OS. In a control-case matched analysis, PFS and OS were prolonged in patients who received VMP in comparison with those treated with MPT.

Prognostic value of deep sequencing method for minimal residual disease detection in multiple myeloma

We assessed the prognostic value of minimal residual disease (MRD) detection in multiple myeloma (MM) patients using a sequencing-based platform in bone marrow samples from 133 MM patients in at least very good partial response (VGPR) after front-line therapy. Deep sequencing was carried out in patients in whom a high-frequency myeloma clone was identified and MRD was assessed using the IGH-VDJH, IGH-DJH, and IGK assays. The results were contrasted with those of multiparametric flow cytometry (MFC) and allele-specific oligonucleotide polymerase chain reaction (ASO-PCR). The applicability of deep sequencing was 91%. Concordance between sequencing and MFC and ASO-PCR was 83% and 85%, respectively. Patients who were MRD(-) by sequencing had a significantly longer time to tumor progression (TTP) (median 80 vs 31 months; P < .0001) and overall survival (median not reached vs 81 months; P = .02), compared with patients who were MRD(+). When stratifying patients by different levels of MRD, the respective TTP medians were: MRD ≥10(-3) 27 months, MRD 10(-3) to 10(-5) 48 months, and MRD <10(-5) 80 months (P = .003 to .0001). Ninety-two percent of VGPR patients were MRD(+). In complete response patients, the TTP remained significantly longer for MRD(-) compared with MRD(+) patients (131 vs 35 months; P = .0009).

Mechanism of immunomodulatory drugs' action in the treatment of multiple myeloma

Although immunomodulatory drugs (IMiDs), such as thalidomide, lenalidomide, and pomalidomide, are widely used in the treatment of multiple myeloma (MM), the molecular mechanism of IMiDs' action is largely unknown. In this review, we will summarize recent advances in the application of IMiDs in MM cancer treatment as well as their effects on immunomodulatory activities, anti-angiogenic activities, intervention of cell surface adhesion molecules between myeloma cells and bone marrow stromal cells, anti-inflammatory activities, anti-proliferation, pro-apoptotic effects, cell cycle arrest, and inhibition of cell migration and metastasis. In addition, the potential IMiDs' target protein, IMiDs' target protein's functional role, and the potential molecular mechanisms of IMiDs resistance will be discussed. We wish, by presentation of our naive discussion, that this review article will facilitate further investigation in these fields.

Efficacy of Subcutaneous Bortezomib in the Management of Patients with Multiple Myeloma or Relapsed Mantle Cell Lymphoma

The identification of the ubiquitin–proteasome system as a new therapeutic target has been one of the most recent successes in cancer treatment. The development and clinical approval of the first-in-class proteasome inhibitor, bortezomib has revolutionized the treatment of multiple myeloma (MM) and mantle cell lymphoma (MCL). In MM, bortezomib is now integrated in induction, conditioning, consolidation, maintenance, and salvage treatment protocols. Bortezomib-based regimens provide high remission rates and confer significant survival advantage compared to conventional chemotherapy in both the bone marrow transplant and non-transplant setting. In MCL, overall response rates in patients who have received at least one prior therapy range from 30 to 45%, even in chemotherapy resistant patients. Clinical trials to further improve the sequencing of bortezomib-containing combination therapies are ongoing. Until recently, intravenous injection was the standard route of bortezomib administration. However, severe adverse side effects, peripheral neuropathy in particular, were observed in up to 16% of MM patients and up to 54% of MCL patients treated with intravenous bortezomib, with grade 3 and 4 in 11 and 12% of patients, respectively. Moreover, complete remission rates, if at all, are low and duration of response is short both in MM and MCL. These limitations may be overcome by changing the method of bortezomib administration as well as by rationally combining bortezomib with other therapeutic agents. Indeed, recent data demonstrate that subcutaneous bortezomib administration is non-inferior to intravenous administration, with an improved systemic safety profile, good local tolerance, and a more convenient route of administration. Based on these data, subcutaneous bortezomib injection was approved as a supplemental new drug application for all approved indications in MM and MCL after at least one prior therapy. More than 30 clinical trials in MM and MCL are currently ongoing to evaluate the efficacy and safety profile of subcutaneous bortezomib also in induction, maintenance, and salvage therapy.

Bortezomib in combination with thalidomide or lenalidomide or doxorubicin regimens for the treatment of multiple myeloma: a meta-analysis of 14 randomized controlled trials

The aim of the study was to evaluate the clinical efficacy and safety of bortezomib-based regimens for the treatment of multiple myeloma through meta-analysis. The literature on three classes of bortezomib-based regimens - bortezomib and thalidomide (VT), bortezomib and lenalidomide (VR) and bortezomib and doxorubicin (VD) - was systematically retrieved and analyzed. The initial search yielded 4896 citations, of which 14 randomized controlled trials (RCTs) (a total of 5379 patients enrolled) met the pre-specified inclusion criteria. The results indicated that the VT regimen had an improved benefit in complete remission (CR) and overall response rate (ORR), but not in progression-free survival (PFS), overall survival (OS) and major grade III/IV adverse events such as peripheral neuropathy, thrombotic events and infection. In contrast, the VD regimen had an improved CR with fewer thrombotic events, while PFS, OS, ORR and the other adverse events showed no significant difference. No significant difference was observed in CR, ORR and major grade III/IV adverse events when comparing the VR regimen with bortezomib and cyclophosphamide (VC), but patients receiving VR regimen therapy had obviously longer PFS and OS.

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.

Treatment with bortezomib-based regimens improves overall response and predicts for survival in patients with primary or secondary plasma cell leukemia: Analysis of the Greek myeloma study group

Plasma cell leukemia (PCL) is a rare and aggressive plasma cell disorder, with poor outcome. Bortezomib-based regimens (BBR) are highly effective in myeloma, but there is limited information about their efficacy and safety in PCL. Thus, we retrospectively collected data from 42 consecutive PCL patients (25 with primary PCL-pPCL and 17 with secondary PCL-sPCL) to explore the role of BBR in this entity. BBR were administered in 29 of 42 patients, while 6 of 25 patients with pPCL underwent autologous transplantation. Objective response (≥partial response) was significantly higher in patients treated with BBR versus conventional therapies (69% vs. 30.8%, P = 0.04); 27.5% of patients treated with BBR achieved at least very good partial response (vgPR). The highest ORR was observed in pPCL patients treated with BBR (88.9%; ≥vgPR: 33.3%). In BBR-group, grade 3 of 4 hematological, neurological and renal toxicity and neutropenic infections were observed in 41.4%, 7%, 3.4%, and 31%, respectively. With a median follow-up of 51 months, median overall survival (OS) for patients treated with BBR versus conventional therapies was 13 versus 2 months (P < 0.007). Median OS of patients with pPCL and sPCL treated with BBR was 18 and 7 months, respectively (P < 0.001). In the multivariate analysis normal PLTs, treatment with BBR and high quality response were the only powerful predictors for survival. Our study carrying the longest reported median follow-up, demonstrated that treatment of PCL with BBR induces high response rates and prolongs survival over conventional therapies, regardless of additional autologous transplantation rescue or established high risk features, with manageable toxicity.

Incidence and risk of cardiotoxicity associated with bortezomib in the treatment of cancer: a systematic review and meta-analysis

Background

We conducted a systematic review and meta-analysis to clarify the incidence and risk of cardiotoxicity associated with bortezomib in cancer patients.

Methods

Databases from PubMed, Web of Science and abstracts presented at ASCO meeting up to July 31, 2013 were searched to identify relevant studies. Eligible studies included prospective phase II and III trials evaluating bortezomib in cancer patients with adequate data on cardiotoxicity. Statistical analyses were conducted to calculate the summary incidence, odds ratio (OR) and 95% confidence intervals (CIs) by using either random effects or fixed effect models according to the heterogeneity of included studies.

Results

A total of 5718 patients with a variety of malignancies from 25 clinical trials were included in our analysis. The incidence of all-grade and high-grade cardiotoxicity associated with bortezomib was 3.8% (95%CI: 2.6–5.6%) and 2.3% (1.6–3.5%), with a mortality of 3.0% (1.4–6.5%). Patients treated with bortezomib did not significantly increase the risk of all-grade (OR 1.15, 95%CI: 0.82–1.62, p = 0.41) and high-grade (OR 1.13, 95%CI: 0.58–2.24, p = 0.72) cardiotoxicity compared with patients treated with control medication. Sub-group analysis showed that the incidence of cardiotoxicity varied with tumor types, treatment regimens and phases of trials. No evidence of publication bias was observed.

Conclusions

The use of bortezomib does not significantly increase the risk of cardiotoxicity compared to control patients. Further studies are recommended to investigate this association and risk differences among different tumor types, treatment regimens and phases of trials.

Bortezomib-melphalan-prednisone-thalidomide followed by maintenance with bortezomib-thalidomide compared with bortezomib-melphalan-prednisone for initial treatment of multiple myeloma: updated follow-up and improved survival

PURPOSE

Bortezomib-melphalan-prednisone (VMP) has improved overall survival in multiple myeloma. This randomized trial compared VMP plus thalidomide (VMPT) induction followed by bortezomib-thalidomide maintenance (VMPT-VT) with VMP in patients with newly diagnosed multiple myeloma.

PATIENTS AND METHODS

We randomly assigned 511 patients who were not eligible for transplantation to receive VMPT-VT (nine 5-week cycles of VMPT followed by 2 years of VT maintenance) or VMP (nine 5-week cycles without maintenance).

RESULTS

In the initial analysis with a median follow-up of 23 months, VMPT-VT improved complete response rate from 24% to 38% and 3-year progression-free-survival (PFS) from 41% to 56% compared with VMP. In this analysis, median follow-up was 54 months. The median PFS was significantly longer with VMPT-VT (35.3 months) than with VMP (24.8 months; hazard ratio [HR], 0.58; P < .001). The time to next therapy was 46.6 months in the VMPT-VT group and 27.8 months in the VMP group (HR, 0.52; P < .001). The 5-year overall survival (OS) was greater with VMPT-VT (61%) than with VMP (51%; HR, 0.70; P = .01). Survival from relapse was identical in both groups (HR, 0.92; P = .63). In the VMPT-VT group, the most frequent grade 3 to 4 adverse events included neutropenia (38%), thrombocytopenia (22%), peripheral neuropathy (11%), and cardiologic events (11%). All of these, except for thrombocytopenia, were significantly more frequent in the VMPT-VT patients.

CONCLUSION

Bortezomib and thalidomide significantly improved OS in multiple myeloma patients not eligible for transplantation.

International Myeloma Working Group consensus statement for the management, treatment, and supportive care of patients with myeloma not eligible for standard autologous stem-cell transplantation

PURPOSE

To provide an update on recent advances in the management of patients with multiple myeloma who are not eligible for autologous stem-cell transplantation.

METHODS

A comprehensive review of the literature on diagnostic criteria is provided, and treatment options and management of adverse events are summarized.

RESULTS

Patients with symptomatic disease and organ damage (ie, hypercalcemia, renal failure, anemia, or bone lesions) require immediate treatment. The International Staging System and chromosomal abnormalities identify high- and standard-risk patients. Proteasome inhibitors, immunomodulatory drugs, corticosteroids, and alkylating agents are the most active agents. The presence of concomitant diseases, frailty, or disability should be assessed and, if present, treated with reduced-dose approaches. Bone disease, renal damage, hematologic toxicities, infections, thromboembolism, and peripheral neuropathy are the most frequent disabling events requiring prompt and active supportive care.

CONCLUSION

These recommendations will help clinicians ensure the most appropriate care for patients with myeloma in everyday clinical practice.

Multiple myeloma maintenance therapy: a review of the pharmacologic treatment

Over the last decade, numerous drug therapies have emerged for the treatment of multiple myeloma including immunomodulating agents namely thalidomide, lenalidomide, and pomalidomide and proteasome inhibitors namely bortezomib and carfilzomib. These agents have transformed the treatment of multiple myeloma and the role of high-dose chemotherapy followed by stem cell transplantation in the treatment of the disease. There are now studies that evaluate the use of drug therapy as maintenance following autologous stem cell transplantation; these studies have shown improvements in surrogate endpoints such as progression-free survival. Studies that have evaluated thalidomide or lenalidomide maintenance therapy have demonstrated an overall survival (OS) benefit in individuals with multiple myeloma who received high-dose chemotherapy followed by stem cell transplantation. A meta-analysis of thalidomide maintenance therapy did show a possible late survival benefit. The use of dexamethasone, thalidomide, lenalidomide, or combination bortezomib with thalidomide in patients who did not undergo transplantation demonstrated progression-free survival benefit; although there was no OS advantage for these agents in this population. There are a number of important considerations when selecting a drug therapy strategy for maintenance therapy which includes practical considerations such as route of administration and frequency of administration. Additionally, patient-specific elements such as potential toxicities, end-organ function, quality of life, cytogenetics, and previous treatment should be considered. Additional studies are needed to elicit the timing for initiation and duration of maintenance therapy, determine the role of cytogenetics, further characterize possible resistance patterns, and determine the combinations necessary to achieve an optimal increase in OS. Until more data are available, the risks and benefits should be evaluated on a patient-specific basis when deciding to initiate maintenance therapy or observation.

The role of histone deacetylase inhibitors in patients with relapsed/refractory multiple myeloma

Clinical outcomes for patients with multiple myeloma (MM) have improved substantially since the introduction of novel agents including the proteasome inhibitor bortezomib and the immunomodulatory drugs thalidomide and lenalidomide. However, most patients with MM eventually relapse, and prognosis remains poor among patients with relapsed and/or refractory disease. Combination therapy using agents with different mechanisms of action is emerging as an attractive treatment approach in oncology to increase efficacy and/or overcome resistance to standard treatment regimens. This review discusses unmet needs in the treatment of MM and the development of histone deacetylase inhibitors as a treatment modality for MM.

Frontline therapy for multiple myeloma: a concise review of the evidence based on randomized clinical trials

The past decade has seen significant progress in the development of new and effective therapies for multiple myeloma. Stem cell transplantation and the introduction of novel agents, such as thalidomide, lenalidomide, and bortezomib, have significantly improved outcomes of myeloma patients. In the current review, we analyzed the available data provided by published randomized clinical trials for the frontline therapy of myeloma patients. We attempted to assess the relative contribution and impact of these new therapies in the setting of both, transplant eligible and transplant ineligible patients.

Optimal management of elderly patients with myeloma

Many advances have been made in the treatment of patients with multiple myeloma including elderly subjects. The introduction of novel agents, such as thalidomide, lenalidomide, bortezomib, have revolutionized the treatment paradigm of this neoplasm, and second-generation molecules are currently being tested to offer patients a wider variety of treatment options and to improve outcome. The efficacy of a regimen should be carefully balanced against its toxicity profile. Elderly patients are particularly susceptible to adverse events that may lead to early treatment discontinuation. Thus, a more accurate distinction within the elderly population and a more appropriate treatment allocation is necessary. Here we describe the major and more recent treatment options available today for elderly patients with multiple myeloma.

Initial treatment of transplant-ineligible patients in multiple myeloma

Over two-thirds of newly diagnosed multiple myeloma are over 65 years. The treatment goals for the non-transplant-eligible patients should be to prolong survival by achieving the best response, while ensuring quality of life. New upfront treatment combinations based on first generation of novel proteasome inhibitors and immunomodulatory drugs plus alkylating agents, the historical platform, have significantly improved outcomes in the past 10 years. Other non-alkylator induction regimens, essentially lenalidomide plus low-dose dexamethasone are also available and provide a novel backbone that may be combined with novel second- and third-generation drugs. Data indicate that prolonged treatment extends the progression-free survival. In summary, this group requires individualized and dose-modified regimens to improve tolerability and efficacy, while maintaining their quality of life.

The effects of bortezomib on bone disease in patients with multiple myeloma

Bortezomib has demonstrated substantial activity in the treatment of patients with multiple myeloma and is widely incorporated into treatment strategies across the different settings. It is interesting to note that data are accumulating to suggest that the activity of bortezomib extends beyond the tumor cell and microenvironment to encompass effects on bone metabolism. Indeed, data from both the preclinical and clinical settings have suggested that bortezomib directly stimulates osteoblast growth and differentiation, while also inhibiting osteoclast development and activity. Notably, in the clinical setting, the bone anabolic effects of bortezomib could be demonstrated by the healing of lytic lesions as noted in some patients. These results are of importance because bone disease is a hallmark of myeloma and therefore any agent that combines antimyeloma activity with positive effects on bone is of substantial interest. However, further studies are needed to establish how the agent should be used for the treatment of patients with bone disease.

Phytohemagglutinin-induced IL2 mRNA in whole blood can predict bortezomib-induced peripheral neuropathy for multiple myeloma patients

The proteasome inhibitor bortezomib has revolutionized the treatment of multiple myeloma. However, bortezomib-induced peripheral neuropathy (BiPN) is a serious complication that compromises clinical outcome. If patients with a risk of developing BiPN could be predicted, physicians might prefer weekly, reduced-dose, or subcutaneous approaches. To seek biomarkers for BiPN, we conducted a multicenter prospective study using a simple and unique system. Multiple myeloma patients received twice-weekly or weekly 1.3 mg/m(2) bortezomib intravenously, and a 2-ml sample of whole blood was obtained before treatment and 2-3 days and 1-3 weeks after the first dose. Induction of gene expression was then quantified by real-time PCR. Of a total of 64 enrolled patients, 53 patient samples qualified for mRNA analysis. The BiPN grade was associated with phytohemagglutinin-induced IL2, IFNG and TNFSF2, as well as with lipopolysaccharide-induced IL6 levels. More importantly, of the 19 patients showing a 3-fold increase in phytohemagglutinin-induced IL2, 14 did not suffer from BiPN (73.7% prediction), whereas of the 34 patients with a <3-fold increase, 23 experienced BiPN (67.6% prediction). Therefore, we concluded that pretreatment of phytohemagglutinin-induced IL2 mRNA levels in whole blood serve as a promising biomarker for predicting BiPN, and this finding warrants validation in a larger study.

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 old drug with a new future: bendamustine in multiple myeloma

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Risk of secondary primary malignancies in maintenance therapy for multiple myeloma

SUMMARY There have been many advances in the treatment of patients with multiple myeloma over the past decade. As a result, the average life expectancy of patients with MM has improved. New medications, including immunomodulatory drugs (thalidomide, lenalidomide and pomalidomide) and proteasome inhibitors (bortezomib and carfilzomib) have entered clinical practice. On average, these medications are easier to tolerate than traditional chemotherapy allowing for long-term use of these drugs in a maintenance fashion. Clinical trials have appeared to establish the benefit of lower dose maintenance therapy for MM patients after induction chemotherapy and/or autologous stem cell transplant. These medications have been shown to improve not only the progression-free survival of patients, but also improve their overall survival compared with observation alone in some pivotal studies. With long-term maintenance therapy, a notable increase in secondary primary malignancies has been described. The exact mechanism behind this increase is uncertain, but may relate to the persistence of CD34+ cells in the setting of continued immunomodulatory exposure. Despite the concern of secondary primary malignancies, the risk:benefit ratio still favors maintenance therapy in many patients with multiple myeloma.