Thalidomide in combination with vincristine, epirubicin and dexamethasone (VED) for previously untreated patients with multiple myeloma

Mechanisms Contributing to Acquired Activated Protein C Resistance in Patients Treated with Thalidomide: A Molecular Dynamics Study

INTRODUCTION

There is a high incidence of venous thromboembolism (VTE) in patients with Multiple Myeloma (MM), however; until now, the exact mechanisms behind VTE in MM are unknown, and some of the elements that may play a significant role are the treatment with an immunomodulator (IMiD) and acquired resistance to activated protein C (APC).

OBJECTIVE

The study aims to reveal the possible mechanisms linked to the reduced antithrombotic activity of APC associated with thalidomide.

METHODS

The molecular docking approach was used to ascertain the in silico inhibitory potential of thalidomide on the APC protease domain in the architecture of the catalytic triad and its interaction with major substrate binding sites.

RESULTS

The coupling showed that the inhibitory activity of thalidomide depends on the induction of structural changes in the protease domain of APC, at the level of the Ser/His/Asp catalytic triad, as a result of a significant increase between the distances of CαAsp102 and Cα Ser195 (11.175 angstroms, increase 14.83%) and between CαSer195 and CαHis57 (9.478 angstroms, increase 13.78 %). This can result in an inefficient transfer of the proton between these residues, the other possible mechanism of inhibition, is a potential reduced binding of the substrate as a result of a direct interaction through a carbon-hydrogen bond on His57, an H-bond on Arg306, and a carbon hydrogen bond on Arg506.

CONCLUSION

We demonstrate the in silico inhibitory potential of thalidomide on APC, through two possible inhibition mechanisms, a pathophysiologically relevant finding to understand the factors that can affect the stability and functions of APC in vivo.

When Two Maladies Meet: Disease Burden and Pathophysiology of Stroke in Cancer

Stroke and cancer are disabling diseases with an enormous global burden, disproportionately affecting vulnerable populations and low- and middle-income countries. Both these diseases share common risk factors, which warrant concerted attention toward reshaping population health approaches and the conducting of fundamental studies. In this article, an overview of epidemiological trends in the prevalence and burden of cancer and stroke, underlying biological mechanisms and clinical risk factors, and various tools available for risk prediction and prognosis are provided. Finally, future recommendations for research and existing gaps in our understanding of pathophysiology. Further research must investigate the causes that predispose patients to an increased risk of stroke and/or cancer, as well as biomarkers that can be used to predict growing morbidity and mortality.

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

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

Rates of venous thromboembolism in multiple myeloma patients undergoing immunomodulatory therapy with thalidomide or lenalidomide: a systematic review and meta-analysis

INTRODUCTION

The incidence of venous thromboembolism (VTE) in patients with multiple myeloma (MM) treated with thalidomide- and lenalidomide-based regimens is high. Recent observational studies have suggested that thromboprophylaxis might be efficacious in decreasing the risk of VTE in this population.

PURPOSE

To determine the absolute rates of VTE with and without different thromboprophylactic agents in patients with newly diagnosed or previously treated MM receiving thalidomide- or lenalidomide-based regimens.

RESULTS

Patients with newly diagnosed MM treated with thalidomide in combination with dexamethasone have a VTE risk of 4.1 (95% CI, 2.8-5.9) per 100 patient-cycles. Therapeutic doses of anticoagulants seem to provide the largest absolute risk reduction of VTE. The rate of VTE in patients with previously treated MM receiving thalidomide in combination with dexamethasone is 0.8 (95% CI, 0.1-2.1) per 100 patient-months. A combination of lenalidomide and dexamethasone is associated with of risk of VTE of 0.8 (95% CI, 0.07-2.0) per 100 patient-cycles and 0.7 (95% CI, 0.4-0.9) per 100 patient-cycles in patients with newly diagnosed and previously treated MM, respectively. Similarly, the rates of VTE in patients also receiving thromboprophylaxis with aspirin were 0.9 (95% CI, 0.5-1.5) and 0.6 (95% CI, 0.01-2.1), respectively.

CONCLUSION

Patients with newly diagnosed or previously treated MM receiving thalidomide- or lenalidomide-based regimens in combination with dexamethasone are at high risk of VTE. The benefit of various types of thromboprophylaxis is difficult to quantify in patients with MM receiving immunomodulatory therapy, especially in those receiving lenalidomide-based therapy or who have previously treated MM. Randomized controlled trials are needed to address this important clinical need.

Monoclonal gammopathy of undetermined significance and risk of venous thromboembolism

BACKGROUND

Patients with multiple myeloma are at increased risk of venous thromboembolism (VTE), but little information is available on VTE risk in patients with the precursor condition monoclonal gammopathy of undetermined significance (MGUS).

OBJECTIVE

To evaluate the risk of VTE and its impact on mortality in patients with MGUS.

PATIENTS AND METHODS

We identified 1610 patients with MGUS and no prior diagnosis of VTE during the 1978-2005 period in North Jutland County, Denmark. We used the Danish Central Population Registry to select 16,100 general population comparison cohort members with no prior VTE diagnosis, matched with the MGUS patients by age, sex, and comorbidity. Follow-up data on VTE incidence in the two groups were obtained from the Danish National Patient Registry covering all Danish hospitals. Time-varying Cox regression analysis was used to compute the incidence rate ratio (IRR) of VTE and the mortality rate ratio (MRR) for MGUS patients who developed VTE compared to MGUS patients without VTE.

RESULTS

In the MGUS cohort, 50 VTE events were identified during 12,594 person-years (PY) of follow-up, corresponding to an incidence rate of 4.0 VTEs/1000 PY. The IRR for VTE among MGUS patients compared to the comparison cohort was 1.37 (95% confidence interval (CI): 1.00-1.88). Of the 50 MGUS patients with VTE, one was later diagnosed with malignant transformation. The adjusted MRR for MGUS patients with VTE compared to MGUS patients without VTE was 1.94 (95% CI: 1.36-2.77).

CONCLUSIONS

MGUS is a risk factor for VTE, and VTE is a marker for increased mortality among MGUS patients.

Consensus guidelines for the optimal management of adverse events in newly diagnosed, transplant-ineligible patients receiving melphalan and prednisone in combination with thalidomide (MPT) for the treatment of multiple myeloma

Thalidomide has received approval from the European Agency for the Evaluation of Medicinal Products for the treatment of newly diagnosed multiple myeloma (MM) patients older than 65 years or ineligible for transplant. The results of five phase III trials assessing thalidomide in combination with melphalan and prednisone (MPT) have demonstrated significantly improved response rates compared with melphalan and prednisone (MP) alone. Additionally, two of these studies showed that survival was extended by approximately 18 months in patients treated with MPT compared with MP alone. Thalidomide, in combination with MP, is associated with adverse events (AEs) including peripheral neuropathy and venous thromboembolism. In order to optimize the efficacy of MPT, a good awareness of these AEs is imperative. This manuscript outlines both evidence- and consensus-based recommendations discussed by a panel of experts, to provide a practical guide for physicians addressing the effective management of newly diagnosed, transplant-ineligible MM patients receiving thalidomide therapy.

Venous thromboembolism in myelodysplastic syndrome patients receiving lenalidomide: results from postmarketing surveillance and data mining techniques

BACKGROUND AND OBJECTIVES

Multiple myeloma treatment with lenalidomide-based regimens is associated with risk of venous thromboembolism (VTE), particularly during concomitant use with erythropoiesis-stimulating agents (ESAs). The risk of VTE in myelodysplastic syndrome (MDS) patients treated with lenalidomide is not well characterized and the background risk in untreated patients is not known. This study set out to determine the reporting rate of VTE in MDS patients on lenalidomide in the two years of postmarketing experience in the US, and to investigate whether there is a disproportional signal of VTE in MDS patients on lenalidomide by screening the US FDA Adverse Event Reporting System (AERS) safety database.

METHODS

The MDS population exposed to lenalidomide was obtained from RevAssist, the company's proprietary restrictive distribution programme. VTE reports were identified from the company's postmarketing surveillance safety database. The FDA AERS database was used for disproportionality analysis, and signal scores computed using three algorithms: multi-item gamma Poisson shrinker (MGPS), proportional reporting ratio (PRR), and reporting odds ratios (ROR).

RESULTS

A total of 7764 MDS patients were prescribed lenalidomide during the first two years of commercial use in the US. VTE representing deep vein thrombosis and pulmonary embolism was reported in 41 patients, a reporting rate of 0.53%. The computed signal scores did not exceed the statistical threshold for identification of a significant disproportional signal for VTE in MDS reports involving use of lenalidomide without concomitant use of ESAs. However, a disproportional signal of VTE was detected in MDS reports where lenalidomide was concurrently used with ESAs.

CONCLUSION

The VTE reporting rate for MDS patients receiving lenalidomide during the first two years of postmarketing exposure was low (0.53%). Disproportionality analysis demonstrated a statistically meaningful association of VTE with lenalidomide concomitantly used with ESAs in MDS patients, but the association was not statistically significant when lenalidomide was used in the absence of ESAs.

Pathogenesis and management of bleeding and thrombosis in plasma cell dyscrasias

Unexpectedly high rates of venous thromboembolic events (VTE) concurrent with the introduction of highly effective immune modulating drugs thalidomide and lenolidomide for treatment of multiple myeloma have focused attention on the incidence and underlying pathophysiology of VTE in patients with plasma cell dyscrasias, and on thromboprophylaxis approaches. While bleeding complications are relatively uncommon in patients with lymphoproliferative disorders, acquired von Willebrand syndrome, typically occurring in patients with monoclonal gammopathy of unknown significance, and acquired coagulopathies associated with primary amyloidosis can present with haemorrhagic complications and both are challenging to manage. This review highlights these important haemostasis-related complications of plasma cell dyscrasias and provides an overview of other uncommon bleeding and thrombotic events that can affect diagnostic and therapeutic management of clonal plasma cell disorders. Due to the infrequency of most of these haemostasis complications, available information is typically based on retrospective cases or series.

Arterial thrombosis and thalidomide

Arterial emboli are largely a reflection of cardiac disease. Thalidomide is an antiangiogenic drug used in cancer therapy. Venous thrombosis incidence increased during treatment with thalidomide. We reported arterial thrombosis in two cases with multiple myeloma implemented in thalidomide treatment. Standard emergency intervention was applied. In the postoperative period, enoxiparine was given to all the patients. Warfarin treatment was started in the level of INR 2-2,5. ASA with a dose of 100 mg/day was added to the treatment. In conclusion, this side effect of the use of thalidomide should be taken into consideration while doing examinations with respect to the etiology in arterial thromboembolism and because of this vascular complication that threatens life; we suggest stopping the thalidomide treatment.

Thalidomide for treatment of multiple myeloma: 10 years later

Thalidomide, bortezomib, and lenalidomide have recently changed the treatment paradigm of myeloma. In young, newly diagnosed patients, the combination of thalidomide and dexamethasone has been widely used as induction treatment before autologous stem cell transplantation (ASCT). In 2 randomized studies, consolidation or maintenance with low-dose thalidomide has extended both progression-free and overall survival in patients who underwent ASCT at diagnosis. In elderly, newly diagnosed patients, 3 independent randomized studies have reported that the oral combination of melphalan and prednisone plus thalidomide (MPT) is better than the standard melphalan and prednisone (MP). These studies have shown better progression-free survival, and 2 have shown improved overall survival for patients assigned to MPT. In refractory-relapsed disease, combinations including thalidomide with dexamethasone, melphalan, doxorubicin, or cyclophosphamide have been extensively investigated. The risks of side effects are greater when thalidomide is used in combination with other drugs. Thromboembolism and peripheral neuropathy are the major concern. The introduction of anticoagulant prophylaxis has reduced the rate of thromboembolism to less than 10%. Immediate thalidomide dose reduction or discontinuation when paresthesia is complicated by pain or motor deficit has decreased the severity of neuropathy. Future studies will define the most effective or the best sequence of combinations which could improve life expectancy.

Prevention of thalidomide- and lenalidomide-associated thrombosis in myeloma

The incidence of venous thromboembolism (VTE) is more than 1 per thousand annually in the general population and increases further in cancer patients. The risk of VTE is higher in multiple myeloma (MM) patients who receive thalidomide or lenalidomide, especially in combination with dexamethasone or chemotherapy. Various VTE prophylaxis strategies, such as low-molecular-weight heparin (LMWH), warfarin or aspirin, have been investigated in small, uncontrolled clinical studies. This manuscript summarizes the available evidence and recommends a prophylaxis strategy according to a risk-assessment model. Individual risk factors for thrombosis associated with thalidomide/lenalidomide-based therapy include age, history of VTE, central venous catheter, comorbidities (infections, diabetes, cardiac disease), immobilization, surgery and inherited thrombophilia. Myeloma-related risk factors include diagnosis and hyperviscosity. VTE is very high in patients who receive high-dose dexamethasone, doxorubicin or multiagent chemotherapy in combination with thalidomide or lenalidomide, but not with bortezomib. The panel recommends aspirin for patients with < or = 1 risk factor for VTE. LMWH (equivalent to enoxaparin 40 mg per day) is recommended for those with two or more individual/myeloma-related risk factors. LMWH is also recommended for all patients receiving concurrent high-dose dexamethasone or doxorubicin. Full-dose warfarin targeting a therapeutic INR of 2-3 is an alternative to LMWH, although there are limited data in the literature with this strategy. In the absence of clear data from randomized studies as a foundation for recommendations, many of the following proposed strategies are the results of common sense or derive from the extrapolation of data from many studies not specifically designed to answer these questions. Further investigation is needed to define the best VTE prophylaxis.

Recent major improvement in long-term survival of younger patients with multiple myeloma

In the past, most patients with multiple myeloma (MM) died within 5 to 10 years after diagnosis. Within the past decade, several new therapeutic interventions have been introduced, including autologous stem-cell transplantation, thalidomide, lenalidomide, and bortezomib. We estimated trends in age-specific 5- and 10-year relative survival of patients with MM in the United States from 1990-1992 to 2002-2004 from the 1973-2004 database of the Surveillance, Epidemiology, and End Results (SEER) Program. Techniques of period analysis were used to show most recent developments. Overall, 5-year relative survival increased from 28.8% to 34.7% (P < .001), and 10-year relative survival increased from 11.1% to 17.4% (P < .001) between 1990-1992 and 2002-2004. Much stronger increases were seen in the age group younger than 50 years, leading to 5- and 10-year relative survival of 56.7% and 41.3% in 2002-2004, and in the age group 50 to 59 years, leading to 5- and 10-year relative survival of 48.2% and 28.6% in 200-2004. By contrast, only moderate improvement was seen in the age group 60 to 69 years, and essentially no improvement was achieved among older patients. Our period analysis discloses a major increase in long-term survival of younger patients with MM in recent years, which most likely reflects the effect of recent advances in therapy and their dissemination in clinical practice.

Prospective evaluation of low-dose warfarin for prevention of thalidomide associated venous thromboembolism

Venous thromboemobolism (VTE) is an important complication of thalidomide therapy especially when it is combined with steroids or chemotherapy. Currently there is no consensus on the most appropriate prophylactic approach. We prospectively investigated the use of low-dose warfarin sodium in prevention of thalidomide-associated VTE in patients receiving thalidomide-based combination therapies. Patients with multiple myeloma or chronic lymphocytic leukemia who were treated on thalidomide based-combination therapies were treated on low-dose warfarin (1 or 2 mg) continuously through the duration of their therapy. Among the 68 patients enrolled, four developed an episode of VTE, an overall incidence of 5.9% (odds = 0.063). Median duration of thalidomide therapy was 4 months. Low-does warfarin decreases the incidence of VTE compared to historical control and is an effective mechanism of prevention of VTE in thalidomide-based chemotherapy regimens.

Supportive care in multiple myeloma

Significant progress in the treatment of multiple myeloma has resulted in improvement of disease control with a trend toward overall and progression-free survival benefit. With the availability of several new therapeutic agents and combinations, a careful emphasis should be placed in the management of disease- and therapy-associated complications. Aggressive management of these complications can impact patients' quality of life as well as treatment outcome. This review highlights some of the critical supportive care measures integral to the optimal care of patients with multiple myeloma.

Immune parameters in multiple myeloma patients: influence of treatment and correlation with opportunistic infections

The present study evaluated cellular and humoral immune parameters in myeloma patients, focusing on the effect of treatment and the risk of opportunistic infections. Peripheral blood lymphocyte subsets and serum levels of nonmyeloma immunoglobulins (Ig) were analysed in 480 blood samples from 77 myeloma patients. Untreated myeloma patients exhibited significantly reduced CD4+/45RO+, CD19+, CD3+/HLA-DR+, and natural killer (NK) cells, as well as nonmyeloma IgA, IgG and IgM. Conventional-dose chemotherapy resulted in significantly reduced CD4+ and even further decline of CD4+/CD45RO+ and CD19+ cells, most notably in relapsed patients. Additional thalidomide treatment had no significant effects on these parameters. Following high-dose chemotherapy (HD-CTX), prolonged immunosuppression was observed. Although CD8+, NK, CD19+ and CD+/CD45RO+ cells recovered to normal values within 60, 90, 360 and 720 days, respectively, CD4+ counts remained reduced even thereafter. Nine opportunistic infections were observed, including five cytomegalovirus (CMV) diseases, one Pneumocystis carinii pneumonia (PCP) and three varicella zoster virus infections with CMV diseases and PCP occurring exclusively after HD-CTX. Opportunistic infections were correlated with severely reduced CD4+, as well as CD4+/CD45RO+ and CD19+ counts. Thus, myeloma patients display cellular and humoral immunodeficiencies, which increase following conventional as well as HD-CTX, and constitute an important predisposing factor for opportunistic infections.

Investigational treatments for multiple myeloma

Multiple myeloma remains a fatal neoplasm and new treatments are urgently needed. In recent years, advances in understanding the molecular pathophysiology of myeloma and the mechanisms of drug resistance led to the development of several novel agents. The drugs with the most available clinical data are thalidomide, bortezomib and lenalidomide. Impressive results obtained with these agents - both in relapsed disease and in newly diagnosed patients - have significantly improved the outcome of myeloma patients. Several other new targeted agents are presently under investigation. These include monoclonal antibodies, agents that target mammalian target of rapamycin, histone acetylation, heat-shock proteins, growth factor signalling cascades, oncogenes, signal transducer and activators of the transcription pathway, Akt pathway and MAPK pathway. Their mechanisms of action, the available knowledge on their efficacy, safety and possible future clinical application are reviewed.

New horizons in multiple myeloma therapy

Recent advances in the understanding of the molecular and biological aspects of multiple myeloma have opened new horizons in the management and treatment of this hitherto incurable disease. With better understanding of the pathobiological 'web' responsible for triggering plasma cells to develop into myeloma, scientists have been able to develop therapeutic strategies that target not only the myeloma cell, but its microenvironment as well. This article will review novel agents commonly used to treat multiple myeloma, either alone or in combination. The role of these agents as induction therapy in newly diagnosed, relapsed and/or refractory disease will also be evaluated. Finally, an overview of novel therapies moving from the bench to the bedside will be provided.

Advances in oral therapy in the treatment of multiple myeloma

Conventional IV chemotherapy regimens used for induction chemotherapy or salvage therapy in the treatment of multiple myeloma (MM) are cumbersome, with a negative impact on patient quality of life. A number of new oral drugs, including immunomodulatory agents such as thalidomide and lenalidomide, have demonstrated potent antimyeloma activity in relapsed and refractory as well as newly diagnosed MM. Clinically, response rates of 56%-72% have been reported with the combination of thalidomide and dexamethasone in patients with newly diagnosed disease; however, the combination is associated with a higher incidence of side effects, including constipation, somnolence, peripheral neuropathy, and thromboembolic complications. In contrast, preliminary safety and efficacy data from clinical studies of lenalidomide show promise. Response rates as high as 83% have been reported in patients with newly diagnosed MM, and the most common adverse event is manageable myelosuppression, which is reversible with dose reduction. Lenalidomide has different toxicities than thalidomide, exhibiting greater myelosuppression but virtually no constipation, somnolence, or peripheral neuropathy. Oncology nurses play a key role in monitoring patients for side effects and pain control and educating them about emerging treatment options. This article reviews the nursing experience with oral agents in the treatment of MM.

Thalidomide in multiple myeloma: past, present and future

Thalidomide was introduced in the treatment of multiple myeloma in the late 1990s. Following the initial results, which demonstrated dramatic response rates in heavily pretreated patients, a number of Phase II studies have confirmed the efficacy of this agent in relapsed patients. However, a high incidence of side effects at the dosage initially recommended (400 mg/day) justified further studies with lower doses of thalidomide given alone or in combination with dexamethasone or chemotherapy. Thalidomide is currently considered as one of the most active agents in relapsed myeloma. Recent studies have demonstrated that thalidomide could also be used as part of frontline therapy. The combination of thalidomide plus dexamethasone as initial therapy appears to be slightly superior to dexamethasone alone or to vincristine–doxorubicine–dexamethasone, but with an increased risk of deep vein thrombosis. Maintenance with thalidomide after autologous transplantation appears to increase the complete remission rate and to prolong progression-free survival. The combination of thalidomide plus melphalan and prednisone is superior to the classical melphalan–prednisone regimen in elderly patients, and will become the standard of care. Thalidomide has been registered in the USA in combination with dexamethasone in newly diagnosed patients, but is not yet registered in the European Union. Its use is currently challenged by bortezomib and by thalidomide’s analog lenalidomide.

Safety and efficacy of thalidomide in recurrent epithelial ovarian and peritoneal carcinoma

OBJECTIVE

Thalidomide is an anti-angiogenesis agent that has shown activity in some solid tumors. We performed a phase I clinical trial to determine the toxicity and potential efficacy of Thalidomide in recurrent epithelial ovarian carcinoma.

METHODS

Patients with recurrent ovarian cancer were evaluated between 1998 and 2000. Data were evaluated using Kaplan-Meier and logistic regression analyses.

RESULTS

17 heavily pretreated patients with recurrent epithelial ovarian cancer received oral Thalidomide starting at 100 mg/day, with dose escalations of 100 mg/day every 2 weeks, up to 1200 mg/day as tolerated. The median number of courses was four (range: 1-18 courses), and median dose was 200 mg/day (range: 100-600 mg/day). Treatment duration ranged from 2 to 48 months. Common grade 1 or 2 side effects included constipation (76%), neuropathy (71%), and fatigue (65%) with few grade 3 or 4 events. Three (18%) patients had partial responses, and six (35%) had stabilization of disease after 6 months. After 1 year of treatment, six of the nine patients with an initial partial response (n=2) or stable disease (n=4) remained in these response categories. Median time to progression was 10 months. Forty-seven percent of patients had a 50-70% decrease in CA125 levels. Using logistic regression and repeated measures analyses, CA125 levels decreased by 62 units/ml per month (p=0.07).

CONCLUSION

Our study demonstrates the safety, tolerability, and potential efficacy of Thalidomide in recurrent and refractory epithelial ovarian cancers. Additional clinical trials are warranted.

Emerging Role of Novel Combinations for Induction Therapy in Multiple Myeloma

Although multiple myeloma (MM) remains an incurable disease, there has been a concerted effort toward understanding its molecular pathogenesis, which has paved the way for the development of highly effective, novel therapeutic agents such as the immunomodulatory agents thalidomide and lenalidomide, and the proteasome inhibitor bortezomib. A better understanding of the molecular basis of chemotherapy resistance and the molecular sequelae of conventional cytotoxic and novel agents on MM cells and the bone marrow microenvironment has afforded the opportunity to study novel, rationally designed combination therapies in the clinic. These regimens have shown impressive activity in relapsed/refractory MM, and recent work has demonstrated unprecedented response rates in the first-line setting rivaling those seen with autologous stem cell transplantation. Recently presented results of 2 phase III clinical trials comparing melphalan/prednisone (MP) with MP and thalidomide (MP-Thal) in older patients with newly diagnosed MM have demonstrated superior progression-free survival and overall survival rates with MP-Thal, thus providing the first evidence that the improved response rates to these novel combination regimens will translate into better patient outcomes. Herein we review the early promising clinical activity of these regimens in patients with newly diagnosed MM.

Thalidomide in multiple myeloma

Multiple myeloma is an incurable bone marrow cancer, the treatment of which is notoriously difficult. Only modest advances have been achieved using complex polychemotherapeutic regimens, transplant strategies and supportive therapy. In 1999, when new drugs for myeloma were urgently needed, thalidomide was introduced and opened up a completely new line of therapy for the disease. Although the mechanism of action is not yet completely understood, thalidomide has demonstrated efficacy in patients with refractory, relapsed myeloma, even in late-stage cases. This article reviews the current knowledge of thalidomide in myeloma treatment, focusing especially on the possible mechanisms of action, clinical results and adverse events of this drug.

Doxorubicin and dexamethasone followed by thalidomide and dexamethasone is an effective well tolerated initial therapy for multiple myeloma

Among the drug combinations designed for the initial treatment of multiple myeloma, none has been unequivocally shown to be superior. However, a regimen leading to a high response rate and a low incidence of adverse events is highly desirable. We report the results of a phase II clinical trial involving 45 patients with Durie-Salmon stage II and III multiple myeloma. Doxorubicin and dexamethasone were given for 2 or 3 months followed by thalidomide and dexamethasone for 2 months (AD-TD regimen) with prophylactic antibiotics and daily aspirin (81 mg/d). Among the 42 patients whose response could be assessed, 38 responded to therapy (90.5%). The intent-to-treat response rate was 84.4% with seven complete responses (CR 15.5%), nine near complete responses (nCR 20.0%), and 22 partial responses (PR 48.9%). Two patients had stable disease (4.4%), and two progression of disease (4.4%). Normalization of the free light chain ratio after one or two cycles of treatment was highly predictive of achievement of CR or nCR. Patients tolerated the treatment well although five patients developed thromboembolic complications (11%). AD-TD administered with low dose aspirin for deep vein thrombosis prophylaxis was well tolerated and yielded a high response rate with minimal treatment-related morbidity.

Thrombotic Complications of Myeloma Therapy

Patients with multiple myeloma are at relatively high baseline risk of developing thromboembolic events (TEE), usually deep vein thromboses. There are numerous contributing factors, among them certain treatment regimens that include thalidomide or related compounds such as lenalidomide combined with glucocorticoids and/or cytotoxic chemotherapy. The risk of developing TEE appears to be particularly high when these immunomodulatory agents are combined with anthracyclines as treatment of newly-diagnosed disease. Up-front combinations including thalidomide plus pulse dexamethasone and/or alkylating agents are associated with an intermediate risk, whereas the same regimens for relapsed/refractory myeloma seem to be associated with the lowest risk. Several different thromboprophylaxis strategies have been effective in lowering the risk of developing clots: daily aspirin (81–325 mg/day), full-intensity warfarin (INR 2–3), and prophylactic enoxaparin (40 mg SQ daily). Low, fixed-dose warfarin may also reduce the risk of TEE, but the data on this are disputable. None of these TEE prevention strategies have been prospectively compared head-to-head, so the choice often reflects physician and/or patient preferences. The available evidence upon which one might make such a decision is reviewed here.

Induction therapy before transplantation in multiple myeloma: new strategies to achieve complete response

The application of high-dose therapy combined with stem cell support has greatly improved the outcome of treatment in patients with multiple myeloma. However, induction treatments are rapidly changing, and it has now become possible to achieve complete responses in 30%-40% of newly diagnosed patients before high-dose therapy. The effect of the improved induction regimens on the results of the whole treatment strategy and the long-term outcome will have to be evaluated in prospective randomized trials. The introduction of new drugs such as thalidomide and bortezomib have contributed significantly to this changed remission status and may ultimately lead to a change of concept about the value of remission-induction therapy. In this article, we review various regimens that are used for induction therapy in preparation for stem cell transplantation and describe the impact these novel agents could have on patient remission status.

Oral melphalan, prednisone, and thalidomide for newly diagnosed patients with myeloma

BACKGROUND

Thalidomide is an immunomodulatory drug with strong antimyeloma activity. It is an effective treatment for multiple myeloma at disease recurrence and at diagnosis, both as a single agent and in combination with steroids or chemotherapy. No data are available on the association of thalidomide with oral melphalan and prednisone, still considered the standard treatment for elderly patients.

METHODS

The feasibility and efficacy of the combination of melphalan, prednisone, and thalidomide (MPT) have been valuated in 49 newly diagnosed patients with multiple myeloma.

RESULTS

According to European Bone Marrow Transplantation/ International Bone Marrow Transplantation Registry (EBMT/IBMTR) criteria, 18% of patients achieved immunofixation-negative complete disease remission (CR), 6% achieved immunofixation-positive near CR, 4% achieved a very good partial response, and 45% achieved a partial response, with a 50-89% reduction in monoclonal paraprotein. Six percent did not respond and 10% showed progressive disease. The median time to maximum response was 4 months. The Kaplan-Meier estimates of event-free survival and overall survival at 2 years were 64% and 91%, respectively. The major acute adverse events (National Cancer Institute Common Toxicity Criteria Grade III-IV) included thrombosis (20%), infections (12%), constipation (6%), and hematologic (22%) and neurologic (8%) toxicities. One patient died of pulmonary thromboembolism.

CONCLUSIONS

These data suggested that MPT induced rapid and durable tumor responses with CR rates similar to those observed after autologous transplantation. Administration of prophylactic anticoagulant was required to prevent thromboembolism. MPT merits further investigation in randomized clinical trials.

Thalidomide in combination with dexamethasone for pretreated patients with multiple myeloma: serum level of soluble interleukin-2 receptor as a predictive factor for response rate and for survival

The aim of this study was to assess the side effects and the efficacy of thalidomide alone or in combination with dexamethasone in relapsed multiple myeloma (MM) and to evaluate possible predictive factors for response rate and survival. Twenty-nine pretreated patients were enrolled, including 13 patients with a relapse after high-dose chemotherapy. The median number of relapses was 3 (range: 1-7). Twenty-two patients received thalidomide in combination with dexamethasone and seven patients thalidomide alone. The dosage of thalidomide was 400 mg/day and the dosage of dexamethasone 20 mg/m2 daily for 4 consecutive days every 3 weeks. Cycles of dexamethasone were given until maximal decline of myeloma protein was achieved, whereas therapy with thalidomide was maintained until disease progression. Responses occurred in 62% of patients, including 5 (17%) complete remissions and 13 (45%) partial remissions. The median event-free survival (EFS) was 7.2 months and the median overall survival (OS) 26.1 months. In multivariate analysis, pretreatment serum levels of soluble interleukin-2 receptor (sIL-2R) were a significant prognostic factor for EFS, and those of beta2-microglobulin (beta2M) and sIL-2R for OS. Serum levels of sIL-2R significantly increased after 3 weeks of treatment in 89% of patients, possibly representing lymphocyte activation induced by thalidomide. Two patients died of septic complications within 3 months after starting treatment with thalidomide and dexamethasone and one patient of herpes encephalitis after 26 months of treatment with thalidomide alone. Also, one case of pneumonia and one case of deep venous thrombosis of the lower limb occurred. Other side effects were somnolence, peripheral neuropathy, and bradycardia occurring in 35, 55, 38 and 55% of patients, respectively. The combination of thalidomide and dexamethasone is an effective therapy in heavily pretreated myeloma patients with a high response rate and acceptable toxicities. A powerful predictive factor both for EFS and OS was the pretreatment serum level of sIL-2R.