Maintenance therapy with alternate-day prednisone improves survival in multiple myeloma patients

The role of high-dose chemotherapy followed by peripheral blood stem cell transplantation for the treatment of multiple myeloma

The management of multiple myeloma has changed significantly over the past 10 years. The results obtained with conventional chemotherapy were disappointing; however the use of high dose therapy (HDT) and stem cell transplantation has significantly improved survival. Autologous, allogeneic and tandem transplantation, along with different conditioning regimens, have been studied in an attempt to optimise and further improve outcomes. This review summarises the role of stem cell transplantation in multiple myeloma. The advent of novel therapies such as thalidomide, lenalidomide and bortezomib have started to redefine the role of peripheral stem cell transplantation, however, further study is needed to better understand how to most effectively use these agents in multiple myeloma in conjunction with HDT.

[New therapeutic strategies for multiple myeloma. Efficacy and cost-effectiveness analyses]

The objective of the present article is the review of the most important therapeutic innovations in the treatment of multiple myeloma in terms of efficacy and cost-effectiveness. Besides autologous transplant with peripheral-blood stem-cell, thalidomide establishes as one of the most powerful therapeutic tools in induction and maintenance treatment and together with lenalidomide and bortezomib as therapy for relapsing/refractory multiple myeloma. Considering, the last named situation thalidomide can be an adequate therapeutical option in combination with dexamethasone. Under a strictly pharmacoeconomic point of view, lenalidomide and bortezomib seem to be additional alternatives in patients previously treated with thalidomide.

Treatment of newly diagnosed multiple myeloma

Multiple myeloma (MM) is the second most common oncohematologic disease. Most patients are older than 65 years at diagnosis, and different therapeutic options are available depending on the age of the patient. For those younger than 65 years, autologous stem cell transplantation is the standard of care, whereas in older patients the better choice is conventional chemotherapy. The introduction of thalidomide, bortezomib, and lenalidomide, which target MM cells and the bone marrow microenvironment, has changed the therapeutic options in newly diagnosed patients with MM.

Frontline treatment in multiple myeloma patients not eligible for stem-cell transplantation

Melphalan-prednisone-thalidomide (MPT) currently appears to be the treatment of choice for a large proportion of elderly patients ineligible for autologous stem-cell transplantation (ASCT). It seems certain that in the near future melphalan-prednisone-Velcade (MPV) and melphalan-prednisone-lenalidomide (MPR) will also be proved superior to melphalan-prednisone (MP), thus providing three therapeutic options (MPT, MPV and MPR) in this patient group with multiple myeloma (MM). These therapeutic options could lead to more personalized treatment approaches, based on patient comorbidities, as the three novel therapies have somewhat different toxicity profiles. MP would be appropriate for only a minority of patients with poor performance status and/or significant comorbidities, such as severe neuropathy or a contraindication to anticoagulants. Questions regarding the relative efficacy of melphalan-based regimens versus dexamethasone-based regimens (preferably with low-dose dexamethasone) will require randomized phase-III trials. More intensive approaches with new drug combinations or with the incorporation of polyethylene glycolated (PEGylated) liposomal doxorubicin will also require additional studies. Additionally, the important issue of maintenance treatment needs to be further investigated, especially in elderly patients.

Clinically relevant end points and new drug approvals for myeloma

This manuscript summarizes the recommendations of the American Society of Hematology/US Food and Drug Administration Workshop on Clinical Endpoints in Multiple Myeloma, which brought together clinical investigators in multiple myeloma, the United States Food and Drug Administration, pharmaceutical companies, patient advocates and other concerned scientists and physicians to provide guidance, consensus and consistency in the definition of clinically relevant end points to expedite new drug approvals for multiple myeloma in the appropriate trial design settings. This manuscript will therefore be a most valuable resource to provide the framework for the design of appropriate clinical trial strategies for more rapid new drug approval in myeloma.

Management of multiple myeloma: the changing landscape

Many changes have been incorporated into the approach to multiple myeloma over the last few years, due to improvements in our understanding of the disease biology. New diagnostic and prognostic criteria from the International Myeloma Working Group have clarified the initial clinical approach to this disease. The prognostic impact of chromosomal abnormalities is now recognized, and the detection of specific abnormal cytogenetics is beginning to influence therapeutic decisions. The introduction of the novel agents thalidomide, bortezomib and lenalidomide has expanded treatment options at different points in the disease course; these agents are being evaluated in conjunction with conventional chemotherapy and stem cell transplantation. This report highlights some of the key recent findings in multiple myeloma, and describes areas for future research.

Lenalidomide in Myeloma

The standard treatment approach to symptomatic myeloma consists of induction therapy, consolidation with high-dose chemotherapy and autologous hematopoietic stem cell transplantation in appropriate patients, maintenance therapy, and salvage therapy. Salvage therapy is of particular importance because not all patients respond to primary therapy, and relapse is virtually universal in responding patients. Newer agents such as thalidomide, bortezomib, and lenalidomide are very active in patients with relapsed or refractory disease. Their use singly and in combination results in excellent cytoreduction including complete remissions in patients relapsing - even after extensive prior therapy. These novel agents have been usually used as salvage therapy in patients relapsing after standard treatment options including transplantation; a setting in which they are thought to improve survival. However, there is an increasing trend to start using them early in the course of the disease; for induction therapy. While early deployment of these agents is certainly associated with high-response rates, evidence that this improves long-term outcome (survival) in patients who subsequently undergo intensive therapy and transplantation is lacking. Toxicity, expense, and possible long-term consequences on the biology of the disease (for example, development of refractory relapse) remain a concern. The most appropriate use of newer agents such as lenalidomide is as salvage therapy of relapsed or refractory disease, and their use as part of induction therapy should be confined to clinical trials until additional data and long-term follow-up are available.

Synthesis and Characterization of Nonsteroidal Glucocorticoid Receptor Modulators for Multiple Myeloma

Structure-activity relationship studies centered around 3'-substituted (Z)-5-(2'-(thienylmethylidene))1,2-dihydro-9-hydroxy-10-methoxy-2,2,4-trimethyl-5H-chromeno[3,4-f]quinolines are described. A series of highly potent and efficacious selective glucocorticoid receptor modulators were identified with in vitro activity comparable to dexamethasone. In vivo evaluation of these compounds utilizing a 28 day mouse tumor xenograft model demonstrated efficacy equal to dexamethasone in the reduction of tumor volume.

High-dose chemotherapy and autologous hematopoietic stem cell transplantation in myeloma patients under the age of 65 years

One or two cycles of high-dose chemotherapy with autologous hematopoietic stem cell transplantation have been shown to improve response rates and survival in myeloma. While this observation has largely been made in patients under the age of 65 years, there is evidence to suggest that the conclusions can be extrapolated to older individuals as well. In contrast to other hematologic malignancies treated with high-dose therapy, autografted myeloma patients continue to relapse several years after transplantation, and few patients are cured with this modality. However, up to a third of patients may be alive beyond a decade; some with excellent quality of life giving rise to the concept of 'operational cure'. Relapsing disease can be treated with novel agents or repeat high-dose chemotherapy and transplantation. The pressing questions to which answers are not obvious at the moment are whether tandem transplantation should be offered to all patients, and whether novel agents should be used before transplantation or reserved for relapse. Despite their excellent activity, there is no evidence so far that novel agents such as thalidomide, bortezomib and lenalidomide can replace high-dose chemotherapy and stem cell transplantation.

The treatment of the elderly multiple myeloma patients

Multiple myeloma (MM) is an incurable malignancy of the plasma cells. Most patients are diagnosed when they are older than 65 years. Therapeutic options include chemotherapy, using either established (e.g. melphalan) or newly available (e.g. thalidomide) drugs and high-dose treatment with stem-cell support (autologous as well as allogeneic). Recent research has focused on defining the target population for the different therapeutic approaches, taking into account pre-treatment characteristics of patients, particularly age, and aims to balance treatment benefit with potential adverse events. In this review we present the data available on the most recent trials dealing with the treatment of elderly MM patients.

Addition of lenalidomide to melphalan in the treatment of newly diagnosed multiple myeloma: the National Cancer Institute of Canada Clinical Trials Group MY.11 trial

Oral melphalan and prednisone remain an effective and tolerable treatment for patients with multiple myeloma. For approximately 40 years, this combination has been the standard of care for patients not proceeding to stem cell transplant. Within the last 10 years, new agents have been found to be efficacious in the relapsed/refractory setting. Within the last year, two trials of added thalidomide in the newly diagnosed setting have demonstrated outcomes superior to those achieved with melphalan and prednisone alone. This improved outcome comes at the cost of increased toxicity.The National Cancer Institute of Canada Clinical Trials Group (NCIC CTG) has recently developed a randomized phase ii trial (MY.11) that uses a combination of lenalidomide with melphalan for patients with newly diagnosed multiple myeloma. Lenalidomide is a thalidomide analogue and, like thalidomide, is thought to work through immunomodulatory effects. It was shown to have activity in patients with relapsed or refractory disease and, in combination with dexamethasone, is superior to dexamethasone alone. Lenalidomide holds promise as a more effective and potentially less toxic derivative of thalidomide. Experience with lenalidomide in combination with chemotherapy is very limited, and the purpose of MY.11 is to establish tolerability and to gain knowledge about efficacy. The information gained from MY.11 is expected to help inform dosing levels and schedules for a large phase iii trial being developed by the Eastern Cooperative Oncology Group that will include participation by the NCIC CTG.

Targeted therapeutics for multiple myeloma: The arrival of a risk-stratified approach

Multiple myeloma (MM) remains an incurable hematologic malignancy characterized by frequent early responses, inevitably followed by treatment relapse. Until recently, few effective therapies existed. Indeed, the use of alkylating agents and corticosteroids had remained the treatment of choice for almost four decades. Several novel agents for MM have now become available, including the immunomodulatory drugs thalidomide and lenalidomide, as well as the proteasome inhibitor bortezomib. Each of these agents is undergoing extensive clinical evaluation in combination with other therapies to produce unprecedented response rates in newly diagnosed and relapsed MM. Nevertheless, relapse remains universal and further therapeutics with broad activity are required. Importantly, it has become clear that pivotal genetic events are the primary harbingers of clinical outcome and novel targeted therapy approaches using existing approved drugs or novel agents, which address that disrupted signaling pathways are now in various stages of clinical testing. It seems increasingly likely that novel drug combinations, which together turn off these critical Achilles heels, will become the standard of care and that treatment will become increasingly personalized and guided by genetic testing and prognostic factors.

Maintenance therapy in multiple myeloma

Therapeutic advances in the treatment of multiple myeloma have significantly improved remission duration and overall survival (OS). These strategies have included the use of immunotherapy (interferon), novel agents (bortezomib, thalidomide, and lenalidomide), corticosteroids, and chemotherapy. While novel agents have had a major impact on response rates with initial therapy, most patients with multiple myeloma will eventually relapse. In the setting of minimal residual disease following standard dose or high-dose therapy, a number of different 'maintenance' strategies have emerged to prolong the duration of initial or subsequent remissions. The impact of these strategies on OS and event-free survival (EFS) is critically important, as the use of ineffective maintenance therapy adds the burden of additional cost, morbidity, and may reduce quality of life. Truly successful maintenance therapy will be effective in the setting of minimal residual disease, and will improve not only EFS, but also OS. This review summarizes the currently available data in the maintenance setting for multiple myeloma, and will discuss potential future trials to further address this important issue.

Treatment of newly diagnosed multiple myeloma based on Mayo Stratification of Myeloma and Risk-adapted Therapy (mSMART): consensus statement

Multiple myeloma is a neoplastic plasma cell dyscrasia that on a yearly basis affects nearly 17,000 individuals and kills more than 11,000. Although no cure exists, many effective treatments are available that prolong survival and improve the quality of life of patients with this disease. The purpose of this consensus is to offer a simplified, evidence-based algorithm of decision making for patients with newly diagnosed myeloma. In cases in which evidence is lacking, our team of 18 Mayo Clinic myeloma experts reached a consensus on what therapy could generally be recommended. The focal point of our strategy revolves around risk stratification. Although a multitude of risk factors have been identified throughout the years, including age, tumor burden, renal function, lactate dehydrogenase, beta2-microglobulin, and serum albumin, our group has now recognized and endorsed a genetic stratification and patient functional status for treatment.

Final Report of Toxicity and Efficacy of a Phase II Study of Oral Cyclophosphamide, Thalidomide, and Prednisone for Patients with Relapsed or Refractory Multiple Myeloma: A Hoosier Oncology Group Trial, HEM01‐21

Thalidomide has direct antimyeloma and immunomodulatory effects. In addition, both thalidomide and metronomic chemotherapy inhibit angiogenesis. The synergy of such a combination may decrease toxicity while maintaining efficacy. The Hoosier Oncology Group conducted a phase II trial of oral cyclophosphamide (50 mg b.i.d. for 21 days), thalidomide (200 mg/day), and prednisone (50 mg q.o.d.) (CTP) per 28-day course in patients with relapsed multiple myeloma (MM). Of the 37 patients enrolled, 16 had prior stem cell transplantation. The median follow-up time was 25.3 months (95% confidence interval [CI] 23.2-27.7). Of 35 patients treated, 22 patients (62.9%) responded: 7 (20.0%) complete responses, 2 (5.7%) near-complete responses, and 13 (37.1%) partial responses. Eight patients (22.9%) had stable disease, and three (8.6%) had disease progression. Two patients withdrew from the study early due to reasons unrelated to progression or toxicity and were treated as nonresponders. The median time to best response and time to progression were 3.6 months (95% CI 2.8-10.9) and 13.2 months (95% CI 9.4-21.0), respectively. The median number of treatment cycles was seven (range 1-12 cycles). Grade III to IV toxicities included leukopenia (42.9%; febrile neutropenia, 11.4%), hyperglycemia (20%), sensory neuropathy (11.4%), thromboses (8%), and motor neuropathy (5.7%). No patient withdrew from the study due to toxicity. The efficacy and low toxicity of the CTP regimen support the future development of such an approach in MM.

A randomised comparison of melphalan with prednisone or dexamethasone as induction therapy and dexamethasone or observation as maintenance therapy in multiple myeloma: NCIC CTG MY.7

The effectiveness of melphalan plus dexamethasone (M-Dex) with melphalan plus prednisone (MP) as induction therapy and dexamethasone with observation as maintenance therapy was compared in 585 older patients with multiple myeloma. Randomization to the M-Dex arm was stopped as a result of an analysis performed which met a predetermined event-related criterion. Of 466 patients randomised to MP or M-Dex, no differences were detected in the respective median progression-free survivals (PFS) [1.8 vs. 1.9 years; Hazard Ratio (HR) = 0.88, 95% CI 0.72-1.07; P = 0.2] or overall survivals (OS) (2.5 vs. 2.7 years; HR = 0.91, 95% CI 0.74-1.11; P = 0.3). Of the initial 585 patients, 292 remained evaluable for maintenance therapy. Patients randomised to maintenance dexamethasone had a superior median PFS (2.8 years vs. 2.1 years; HR = 0.61, 95% CI 0.47-0.79; P = 0.0002). No difference in median OS was detected (4.1 years vs. 3.8 years; HR = 0.88, 95% CI 0.65-1.18; P = 0.4). The maintenance therapy results were robust when analysed by using two additional methodologies. Dexamethasone did not improve clinical outcome when combined with melphalan during induction; maintenance dexamethasone improved PFS, but this did not translate into a detectable survival advantage.

Low tolerance and high toxicity of thalidomide as maintenance therapy after double autologous stem cell transplant in multiple myeloma patients

Although a double autologous peripheral blood stem cell transplant (APBSCT) is an effective therapy for patients (pts) with multiple myeloma and extends progression-free survival and overall survival, pts show a continued pattern of recurrent disease. The feasibility and tolerability of thalidomide (Thal) administered in the post-transplantation period as maintenance therapy was tested in 17 pts at a dose of 100 mg/d starting between 3 and 5 months after the second transplantation and continuing either until toxicity precluded further therapy or until pts had disease progression. After a median administration of 13 months (range: 3-26), 76.5% (13 pts) failed to tolerate Thal because of: transiet ischemic attack (three pts), severe fatigue (two), neutropenia (one), piastrinopenia (one), severe opportunistic infectious (two), erectile impotence (one), gastrointestinal toxicity (anorexia with weight loss one), peripheral neuropathy (two). After a median follow-up of 36 months (range: 10-59) from the second transplant, 13 patients attained a CR + near CR (with a conversion rate from 47.1% to 76.5%). In conclusion, Thal as maintenance therapy after double ASCT is associated with low feasibility and high toxicity and could prevent a lengthy use of this antineoplastic agent.

Stem cell transplantation in multiple myeloma

Multiple myeloma (MM) is one of the key hematologic malignancies in which the impact of dose intensity has been demonstrated. Consequently, in 2005, MM was the most common disease for which autologous stem cell transplantation (ASCT) was indicated both in Europe and in the U.S. However, ASCT is not curative, and most patients relapse within a median of 3 years. Novel agents such as thalidomide (Thalidomid), bortezomib (Velcade), or lenalidomide (Revlimid) have been introduced to improve high-dose therapy, and promising results have been reported. Conversely, results from myeloablative allogeneic stem cell transplantation remain disappointing due to high transplantation-related mortality, justifying the exploration of strategies such as reduced-intensity conditioning, which have been shown to be feasible but for which proof of efficacy requires continued study.

Treatment Strategies in Elderly Patients with Multiple Myeloma

Multiple myeloma (MM), a plasma cell malignancy, is a disorder of the elderly with an increasing prevalence as the average life expectancy increases. Survival remains unacceptably low in elderly patients with MM, in whom the gold standard of treatment has been, until recently, oral melphalan and prednisolone, which induces a response rate of approximately 50% and overall survival of <3 years. In the last 15 years, traditional treatment paradigms for elderly patients with MM have been challenged not only as a result of the change in what we define as 'elderly' but also as a result of the reduced morbidity and treatment-related mortality associated with high-dose chemoradiotherapy (HDT) and autologous stem cell transplantation (ASCT), and the emergence of novel therapies including thalidomide, its immunomodulator drug derivative lenalidomide and the first-in-class proteasome inhibitor, bortezomib. In this review, we examine currently available data regarding the treatment of MM in the elderly population. Recent years have seen a paradigm shift in the standard of care of elderly patients with MM from oral melphalan and prednisolone to approaches including HDT with ASCT using intermediate-dose melphalan in selected elderly patients, and the evaluation of and incorporation of drugs such as thalidomide, bortezomib and lenalidomide. Importantly, we now have been able to change the traditional goal of palliation in the elderly group of patients to a more ambitious objective of achieving a complete response or a near complete response, in the hope that this will translate into improved progression-free survival, overall survival and quality of life.

Thalidomide and lenalidomide in multiple myeloma

Multiple myeloma is a treatable but not necessarily a curable plasma-cell cancer. After decades of minimal progress, two new classes of drugs with novel mechanisms of action - immunomodulatory drugs (thalidomide and lenalidomide) and proteasome inhibitors (bortezomib) - have been introduced for the treatment of this disease. Thalidomide and lenalidomide have shown great activity as single agents and in combination with glucocorticoids for the treatment of chemotherapy-refractory myeloma. Thalidomide - and more recently lenalidomide - in combination with dexamethasone have shown promising results as induction therapy. These drugs can easily be combined with other chemotherapeutic agents to potentiate the anti-myeloma effect. The immunomodulatory function of these drugs can be successfully exploited to control residual disease during remission. Thus, both thalidomide and lenalidomide have ushered in a new era of optimism in the management of this incurable cancer.

Maintenance therapy for multiple myeloma with particular emphasis on thalidomide

Treatment standards are changing as a result of new findings in the therapy of multiple myeloma. So far, prednisone, dexamethasone and interferon-a have mainly been used as maintenance therapy after achieving remission or stable disease. At present, thalidomide is being considered as a new therapeutic option in several studies investigating maintenance therapy. As a result of the dose dependence of adverse effects such as neuropathy, constipation, sedation/vertigo and bradycardia, individual adjustment of the thalidomide dose is recommended. Only isolated cases of thrombosis occurred in the maintenance phase of therapy, and discontinuation of therapy is generally not necessary. While important study results on the efficacy of thalidomide following conventional chemotherapy are still awaited, it is the best documented drug so far for maintenance therapy following autologous stem cell transplantation. An upgrade of the response was seen in 22-73% of patients, as well as a significant prolongation of progression-free survival. For the first time, maintenance therapy with thalidomide showed a significant improvement in overall survival in a phase III study published recently. The tolerability of thalidomide could be further improved by including the option of intermittent administration of the drug.

State of the art therapy in multiple myeloma and future perspectives

Treatment for multiple myeloma (MM) has changed beyond recognition in the past decades. While until the early 1980s, MM caused a slow progressive decline in quality of life until death after about two years, today's patients can expect a 50% chance of achieving a complete remission, a median survival time of five years and a 20% chance of surviving longer than ten years. State of the art therapy comprises: evidence-based supportive care; highly effective and well tolerated chemotherapeutic regimens; and for patients qualifying for intensive high-dose conditioning, autologous haematopoietic stem cell transplantation (HSCT) is an option. Maintenance therapy has become increasingly important since a majority of patients is able to achieve a good remission after front-line therapy which is aimed to be preserved as long as possible. In addition, improved understanding of the disease biology has led to the development of novel biological treatment agents, such as thalidomide, bortezomib and others, targeted at cellular mechanisms and interactions, e.g. with the bone marrow microenvironment. These strategies are incrementally integrated into modern MM care. This review considers recent clinical advancements in anti-myeloma strategies and provides an overview of the state of the art management of MM patients.

Maintenance therapy with thalidomide improves overall survival after autologous hematopoietic progenitor cell transplantation for multiple myeloma

BACKGROUND

High-dose chemotherapy with autologous hematopoietic progenitor cell (HPC) transplantation improves survival for patients with multiple myeloma (MM); however, most patients develop recurrent disease after undergoing transplantation, and new treatment approaches are needed. The objective of this retrospective review of autologous HPC transplantation for patients with MM was to evaluate the impact of conditioning regimens and posttransplantation therapy on survival.

METHODS

The authors reviewed 112 patients with MM who received autologous HPC grafts at their institution. Between June 1992 and August 2001, 54 patients received busulfan, cyclophosphamide, and etoposide (Bu/Cy/VP-16), and 58 patients received high-dose melphalan (MEL-200) followed by autologous HPC transplantation. After transplantation, 36 patients received thalidomide for maintenance or salvage therapy, and 76 patients received no posttransplantation thalidomide.

RESULTS

At a median follow-up of 58 months, the median survival was 54 months. There was no statistically significant difference noted with regard to response to conditioning regimen, progression-free survival, or overall survival between the Bu/Cy/VP-16 and MEL-200 cohorts. Patients who received thalidomide after transplantation had improved median survival (65.5 months) compared with patients who did not receive thalidomide (44.5 months; P = .09). When they were separated according to reasons for thalidomide use, patients who received thalidomide as maintenance had improved overall survival compared with patients who received thalidomide as salvage (65 months vs. 54 months; P = .05).

CONCLUSIONS

Combination chemotherapy provided no advantage over high-dose melphalan in patients with MM who underwent autologous HPC transplantation. The posttransplantation use of thalidomide seemed to improve the survival of patients compared with historical controls from the prethalidomide era. Further prospective trials are underway to confirm the benefit of thalidomide in the posttransplantation setting.

Interference with nuclear factor kappa B and c-Jun NH2-terminal kinase signaling by TRAF6C small interfering RNA inhibits myeloma cell proliferation and enhances apoptosis

The tumor necrosis factor receptor (TNFR)-associated factor (TRAF) family of six adaptor proteins (TRAF1-6) links the TNFR superfamily to the nuclear factor kappa B (NF-kappaB) and activator protein-1 (AP-1) transcriptional activators. Unlike other TRAFs, TRAF6 is also involved in Toll-like/interleukin (IL)-1 receptor (TIR) signal transduction. Thus, inhibition of TRAF6 function could interrupt both CD40 (TNFR family) and IL-1 growth signals, pathways critical to myeloma proliferation. To block TRAF6-mediated IL-1 signaling, we constructed small interfering RNA (siRNA) against TRAF6. We found that siRNA targeting the TRAF6 C-terminal (siTRAF6C) receptor interaction domain specifically reduced only TRAF6 protein expression, without affecting TRAF2 or 5 levels, and substantially interfered with IL-1-induced NF-kappaB and c-Jun/AP-1 activation. Inhibition by siTRAF6C was concentration-dependent. SiTRAF6C also significantly reduced myeloma proliferation and enhanced apoptosis in a similar dose-dependent fashion in vitro. More importantly, marked siTRAF6C growth inhibition was detected in vivo when these cells were implanted into the bone marrow of irradiated normal mice. In contrast, introduction of siRNA derived from the TRAF6 Zn-finger domain or an irrelevant siRNA construct failed to alter cell growth or cell death. These studies suggest that TRAF6 may be a new molecular target to block cell signal transduction important for the survival and proliferation of multiple myeloma cells.

Cure of multiple myeloma -- more hype, less reality

Randomized studies have firmly established the role of autologous transplant as initial therapy in multiple myeloma (MM). Indeed, MM has emerged as the commonest indication for autologous SCT in North America. The conceptual basis for high-dose therapy is the goal of complete remission (CR) through steep reduction in tumor burden affected by single and tandem transplants. Careful analysis of the data challenges the notion of CR as a surrogate to success. Intrinsically aggressive MM, defined by known unfavorable biologic risk factors, overrides the benefit of CR. In contrast, subgroups of patients with favorable biological risk factors may achieve prolonged survival, often without ever achieving CR. Unfortunately, even with tandem transplants, there is no plateau in survival curves. To this end, sequential autologous followed by nonmyeloablative allotransplants are a novel attempt at 'curing' myeloma, but the results thus far have failed to show a definite plateau in survival. Given the improvements in supportive care and concomitant reduction in transplant-related mortality, conventional myeloablative allogeneic transplants need to be re-examined as an option in high-risk aggressive myeloma. At the same time, novel antimyeloma therapies, newer risk stratification and staging tools are transforming the treatment algorithm. We examine the changing role of transplantation in myeloma in the context of novel drug therapy, biologic risk stratification and improving supportive care while arguing that the current 'one size fits all' transplant approaches are far from a cure.

Second autologous or allogeneic transplantation after the failure of first autograft in patients with multiple myeloma

BACKGROUND

Most patients undergoing high-dose therapy and autologous transplant for multiple myeloma eventually develop a disease recurrence. However, to the authors' knowledge, the optimal salvage treatment for these patients is not well defined. Both autologous and allogeneic hematopoietic stem cell transplantations have been used for salvage therapy. The outcomes of salvage autologous or allogeneic transplants were analyzed retrospectively in patients relapsing after an autograft.

METHODS

Fourteen patients (median age, 52 yrs) received a second autograft for salvage, whereas 26 patients (median age, 51 yrs) underwent a reduced-intensity allogeneic transplantation (related in 18 patients and unrelated in 8 patients). The median interval between the first and the second transplant was 25 months in the autologous group and 17 months in the allogeneic group. The two groups were evenly matched with regard to other disease characteristics.

RESULTS

After a median follow-up of 18 months for the autologous group and 30 months for the allogeneic group, the median progression-free survival (PFS) and overall survival (OS) in the 2 groups were 6.8 months versus 7.3 months and 29 months versus 13 months, respectively. Acute and chronic graft versus host disease (15%) was the most common cause of non-recurrence mortality in the allogeneic group and infections (14%) in the autologous group. On univariate analysis, an interval of > 1 year between the first and the salvage transplant predicted a better OS in the allogeneic group.

CONCLUSIONS

Both autografting and allografting are feasible as salvage therapy for myeloma patients who develop disease recurrence after the first autograft, although disease progression remains the major cause of failure. Better approaches are needed for salvage therapy in patients developing disease recurrence after an autograft.

Initial Therapy of Multiple Myeloma Patients Who Are Not Candidates for Stem Cell Transplantation

Multiple myeloma patients deemed to not be candidates for high-dose therapy followed by stem cell rescue who nonetheless need chemotherapy have traditionally received an oral regimen combining melphalan and prednisone. With the advent of novel agents, however, such as immunomodulatory drugs and proteasome inhibitors that are active in the relapsed/refractory setting, there has been an impetus to incorporate these new options into front-line therapy. Several phase II studies have recently revealed that addition of either thalidomide, lenalidomide, or bortezomib to melphalan and prednisone increased the overall and complete response rates, albeit at the cost of some increased toxicity. Randomized phase III studies of melphalan and prednisone with thalidomide have already shown that, compared to melphalan and prednisone alone, the three-drug regimen prolonged time to progression and overall survival in this population, thereby defining a new standard of care. Moreover, our increasing knowledge of the molecular role that cytogenetic abnormalities play in the biology of multiple myeloma and our growing chemotherapeutic armamentarium are beginning to allow us to rationally select therapies based on these characteristics of each patient’s disease. Such a risk- and molecular-adapted strategy to the therapy of multiple myeloma promises to revolutionize and personalize our care of these patients and bring us closer to a cure for this disease.

Conventional therapy and approach to management

The treatment of multiple myeloma (MM) has undergone major changes in the last decade. There is now an array of therapeutic options, including autologous stem-cell transplantation, non-myeloablative (mini) allogeneic transplantation, and new drugs such as thalidomide and bortezomib. There is also an awareness that there are subsets of patients with MM who have not gained much from the recent advances, including patients with certain adverse prognostic factors (high-risk MM). In this article, we outline our approach to the diagnosis, risk stratification and treatment of MM with a focus on conventional therapy. We incorporate a risk-based strategy for the treatment of MM that also takes into account the eligibility of the patient to undergo stem-cell transplantation. We also outline the role and current indications for the use of new active agents in this disease.

Continuous prednisolone versus conventional prednisolone with VMCP-interferon-alpha2b as first-line chemotherapy in elderly patients with multiple myeloma

We report on a randomised trial that aimed to compare the efficacy of continued daily prednisolone treatment during the entire induction phase, with prednisolone given for 2 weeks of each cycle in combination with VMCP (vincristine, melphalan, cyclophosphamide, prednisolone)-interferon-alpha 2b (IFN-alpha 2b) treatment in 299 previously untreated elderly patients (median age: 67 years) with multiple myeloma. After completion of induction treatment patients were randomised to IFN-alpha 2b with or without prednisolone, thrice weekly. Response rate was 62% in the continuous and 60% in the control arm (intent to treat analysis, P=0.81). Progression-free survival [median: 20 months vs. 19 months; hazard ratio (HR): 0.99, 95% confidence interval (CI): 0.74-1.33, P=0.97] and overall survival (median: 34 months vs. 37 months; HR: 1.16, 95% CI: 0.85-1.59, P=0.35) were similar in both groups. Reduced performance status (Eastern Cooperative Oncology Group, grades 2-4) was the predominant risk factor for poor survival followed by age >65 years, high beta2-microglobulin, and impaired renal function. There was more grades 3-4 dyspnoea and cardiac impairment and grades 1-2 hyperglycaemia, but less nausea, emesis and anaemia in patients on continuous prednisolone therapy. In conclusion, continuing prednisolone treatment during the entire duration of the induction phase with VMCP-IFN-alpha 2b did not improve outcome.

Sequential, cycling maintenance therapy for post transplant multiple myeloma

High-dose chemotherapy with autologous stem cell transplantation in patients with newly diagnosed multiple myeloma can prolong survival but is not curative. Maintenance therapy post transplant may prolong the disease-free interval and impact overall survival. We have conducted a phase II pilot study of 28 post transplant myeloma patients treated with a sequential, cycling maintenance regimen. The regimen was designed to include a variety of active myeloma agents chosen for ease of administration to enhance patient compliance and scheduled sequentially to minimize toxicity. The 12-month cycling schedule included dexamethasone (months 1-3); melphalan and prednisone (months 4, 5); cyclophosphamide and prednisone (months 6, 7); alpha-interferon (months 8-10); followed by a drug holiday (months 11, 12). The regimen was generally well tolerated with five patients developing reversible grade III-IV toxicity (diabetes-induced hyperglycemia in four, neutropenia in one). There was one toxic death on study due to non-neutropenic pneumonia and sepsis. Median event-free survival from transplant was 36.9 months (95% CI 23.6 - upper limit not yet reached) with median overall survival not yet reached at a median follow-up of 44 months. This concept of cycling, sequential maintenance with various agents, perhaps including newer biological, targeted agents, warrants further investigation in multiple myeloma.

Multiple myeloma: diagnosis and treatment

Major advances have occurred in our understanding of the biology of multiple myeloma (MM) and in its treatment in the past decade. New diagnostic criteria have been developed, and an international Staging System has replaced the Durle-Salmon Staging System. It is now possible to classify MM as standard risk or high risk on the basis of specific Independent prognostic factors. The role of single and double autologous stem cell transplantation has been clarified by randomized trials. Most importantly, thalidomide, bortezomib, and lenalidomide have emerged as new active agents and are being incorporated rapidly into the treatment of both newly diagnosed and relapsed MM. The current approach to the diagnosis, prognosis, and management of MM is reviewed.

Treatment of myeloma in patients not eligible for transplantation

Multiple myeloma (MM) remains an incurable disease for most patients, with a median survival of 4 to 5 years. High-dose chemotherapy followed by transplantation has resulted in improvement in response rates and survival compared with conventional therapy, but relapse is nearly universal and not all patients are candidates for this option of aggressive treatment. Standard therapeutic strategies for newly diagnosed patients not eligible for transplantation include pulsed high-dose dexamethasone, melphalan with prednisone, and vincristine in combination with doxorubicin and dexamethasone, as well as other combinations of alkylating agents. Emerging therapies under clinical investigation for first-line therapy include thalidomide, the thalidomide analog lenalidomide, and the proteasome inhibitor bortezomib alone and in combination with other agents, particularly dexamethasone. At an interim analysis, thalidomide combined with melphalan and prednisone was shown to induce a complete or near complete remission (CR) rate of 28% and overall (complete+partial) response rate of 77% in elderly patients generally not eligible for transplantation. These results are comparable to those obtained with high-dose therapy and may obviate transplantation in these patients. Induction therapy with bortezomib-based combinations induces complete and near complete remissions in a similar proportion of patients. These regimens include bortezomib and dexamethasone alone and in combination with doxorubicin, thalidomide, or melphalan. Use of thalidomide or bortezomib does not preclude stem cell harvest. Survival benefits need to be firmly established before these novel regimens emerge as the new standard of care for newly diagnosed disease. However, front-line treatment with combinations involving these agents is a promising strategy that may improve the standard of care for patients both eligible and ineligible for stem cell transplantation.

Pilot study of 13cis-retinoic acid+dexamethasone+alpha interferon as maintenance therapy following high-dose chemotherapy and autologous stem cell transplant for multiple myeloma

Interleukin 6 (IL-6) is a major growth factor for myeloma cells and retinoids have been shown to inhibit expression of the interleukin 6 receptor (IL-6R). We performed a pilot study to assess the efficacy and tolerability of 13cis retinoic acid (13cRA) and dexamethasone (Dex), when added to interferon alpha (IFNalpha) as maintenance therapy post autologous stem cell transplantation. Between 90 and 120 days post stem cell transplantation, 33 patients were started on 13cRA 1 mg/kg p.o. daily for 14 days and Dex 40 mg p.o daily for 5 days every month. 13cRA was dose escalated by 0.5 mg/kg/month to 2 mg/kg. Seventeen patients had a persistent paraprotein post transplant. Overall, a response to therapy was observed in 11/17 (64%), with a complete response in 4/17 (23.5%) and a partial response (>/=50% paraprotein decline) in 7/17 (41%). With a median follow-up of 34.8 months, 22/33 (66%) demonstrated disease progression and 11/33 (33%) died. The median progression-free survival from diagnosis was 34.7 months. Although a decline in paraprotein was frequently observed on triple therapy, many patients discontinued therapy due to the side-effects of the IFNalpha. Future trials should be designed using 13cRA and Dex alone.

Evolving treatment strategies for myeloma

In this article, we will discuss how treatment strategies for myeloma have evolved and outline the challenges now faced following the introduction of a number of novel active agents. In particular, we will focus on how achieving a maximum response and maintaining such responses is becoming a key therapeutic strategy and how novel agents can be used to achieve this in the context of current strategies such as autologous transplantation.

Results of a Multicenter Randomized Phase II Trial of Thalidomide and Prednisone Maintenance Therapy for Multiple Myeloma after Autologous Stem Cell Transplant

We report a multicenter, randomized phase II trial conducted to assess the tolerability of combined thalidomide and prednisone maintenance in multiple myeloma. Eligibility required administration of melphalan (200 mg/m2) with blood stem cell support within 1 year of treatment onset and initiation of maintenance within 60 to 100 days after stem cell infusion. All patients received 50 mg of prednisone by mouth on alternate days and thalidomide at a starting dose of either 200 or 400 mg daily by mouth. The primary end point was the incidence of dropout or dose reduction due to treatment toxicity within 6 months. Sixty-seven patients were enrolled. Median follow-up is 36.8 months. The primary end point was reached by 31% of patients on the 200 mg of thalidomide arm and 64% of patients on the 400 mg of thalidomide arm. Allowing for dose reduction, 76% of patients assigned to the 200 mg of thalidomide arm and 41% of patients assigned to the 400 mg of thalidomide arm remained on any maintenance therapy 18 months after registration. Eighty-eight percent of all patients dose-reduced thalidomide and 72% of all patients dose-reduced prednisone within 2 years of beginning maintenance. The median progression-free survival post-transplant is 32.3 months, or 42.2 months from diagnosis. Only the 200 mg of thalidomide arm of this trial met our definition of a tolerable maintenance therapy, defined as no dose reductions or discontinuation due to toxicity in at least 65% of patients for a minimum of 6 months, thus establishing a dosing schedule for phase III trials.

Autologous stem cell transplantation in multiple myeloma patients <60 vs >/=60 years of age

The role of autologous stem cell transplantation (AuSCT) in older multiple myeloma patients is unclear. Using data from the Autologous Blood and Marrow Transplant Registry, we compared the outcome of 110 patients >/=the age of 60 (median 63; range 60-73) years, undergoing AuSCT with that of 382 patients <60 (median 52; range 30-59) years. The two groups were similar except that older patients had a higher beta(2)-microglobulin level at diagnosis (P=0.016) and fewer had lytic lesions (P=0.007). Day 100 mortality was 6% (95% confidence interval 4-9) and 1-year treatment-related mortality (TRM) was 9% (6-13) in patients <60 years, compared with 5% (2-10) and 8% (4-14), respectively, in patients >/=60 years. The relapse rate, progression-free survival (PFS) and overall survival (OS) in the two groups were also similar. Multivariate analysis of all patients identified only an interval from diagnosis to AuSCT >12 months and the use of two prior chemotherapy regimens within 6 months of AuSCT as adverse prognostic factors. Our results indicate that AuSCT can be safely performed in selected older patients: the best results were observed in patients undergoing AuSCT relatively early in their disease course.

Magnitude of response with myeloma frontline therapy does not predict outcome: importance of time to progression in southwest oncology group chemotherapy trials

PURPOSE

Four Southwest Oncology Group (SWOG) standard-dose chemotherapy protocols for multiple myeloma (MM) initiated between 1982 and 1992 were evaluated. The purpose was to clarify the predictive value of specific levels of myeloma-associated monoclonal protein reduction and time to first progression using mature data sets.

PATIENTS AND METHODS

Study data on 1,555 eligible previously untreated patients with MM enrolled onto SWOG phase III trials 8229, 8624, 9028, and 9210 were used in these analyses. Six-month and 12-month landmark analyses were performed to evaluate the outcome for patients in each response category.

RESULTS

The overall and event-free survivals for the four protocols combined were 33 months and 18 months, respectively. Using 6- and 12-month landmarks, the median survivals of 30 to 35 months were not different for responders (> or = 50% and > or = 75% regression) versus nonresponders in patients without disease progression before the landmarks. Conversely, at the 6- and 12-month landmarks, the median survivals for patients who had experienced disease progression were 13 and 15 months, respectively, versus a 34-month median for patients who did not experience progression. Using the Cox survival model, with response and progression considered as time-dependent covariates, survival duration was influenced more by the occurrence of progression than by the occurrence of response.

CONCLUSION

The magnitude of response, as a single variable, does not predict survival duration. Patients with response and stable disease have equivalent outcome. Only patients with progressive disease have a poorer outcome. The best indicator of survival is time to first progression.