Thalidomide alone or in combination with dexamethasone in patients with advanced, relapsed or refractory multiple myeloma and renal failure

Novel agents for relapsed and/or refractory multiple myeloma

The introduction of novel agents, such as thalidomide, bortezomib, and lenalidomide, has altered the landscape of therapeutic options for multiple myeloma by offering new mechanisms for targeting this disease. Combinations of these agents, with each other and/or traditional chemotherapeutics, have vastly increased the treatment options for patients both frontline, and at relapse, providing higher response rates, and importantly, increasing median overall survival. In this review, we will discuss the use of these novel agents and their combinations in patients with relapsed and/or refractory multiple myeloma.

Review Article: Palliative Oncology: Thalidomide

After decades of disuse because of its teratogenic effects, thalidomide has had a resurgence of use as a promising therapeutic agent for multiple myeloma. Its mechanism of action involves activation of the immune system, antiangiogenic effects, and inhibition of cytokines. Thalidomide does not interact with the cytochrome oxidase system. It is not significantly metabolized, but it does undergo nonenzymatic hydrolysis in plasma. The resulting products are inactive. Despite the potential adverse effects of peripheral neuropathy, constipation, deep vein thrombosis, somnolence, rash, and orthostatic hypotension, thalidomide is an effective first-line agent for multiple myeloma in combination with dexamethasone or melphalan and prednisone. It has also been studied in the palliative care of patients with cytokine-based syndromes such as anorexia-cachexia syndrome. This review describes its use in oncology, hematology, and palliative care.

Reversal of dialysis-dependent renal failure in patients with advanced multiple myeloma: single institutional experiences over 8 years

Acute renal failure in patients with multiple myeloma (MM) requiring dialysis is a serious complication and is associated with extremely poor survival. In addition, its treatment included high-dose dexamethasone and/or thalidomide-containing regimens on the reversibility of renal function, which has not been adequately evaluated previously. We studied the impact on the reversibility of high-dose dexamethasone and/or thalidomide-containing regimen in 12 newly diagnosed MM patients (median 74 years, range; 63-85 years) who required dialysis at Kameda General Hospital from 2001 to 2008. There were seven light chain only myelomas, three IgD myelomas, and two IgG myelomas. Ten patients initially received high-dose dexamethasone-based treatment and two received thalidomide-based treatment, with modifications. Complete (CR) and partial responses (PR) were obtained in three and five patients, respectively. Dialysis independency was achieved in all eight patients (67%) who achieved better than PR, with a median duration of 2.0 months. Six of the ten patients who received high-dose dexamethasone-containing regimen and all of the two patients received thalidomide-containing regimen became dialysis-independent. A high concentration of serum-free light chain was detected in all patients examined, before the start of anti-myeloma treatment, and this was associated with the presence of advanced renal failure. Improved renal function was preceded by a significant decrease in serum-free light chain in patients who achieved dialysis independence. These results suggest that dialysis-dependent renal failure is reversible by dexamethasone- or thalidomide-based treatments in most patients with MM, even if the patient is in advanced age, and that serum-free light chain monitoring might be useful for predicting improvements in renal function.

Multiple myeloma

Multiple myeloma is characterised by clonal proliferation of malignant plasma cells, and mounting evidence indicates that the bone marrow microenvironment of tumour cells has a pivotal role in myeloma pathogenesis. This knowledge has already expanded treatment options for patients with multiple myeloma. Prototypic drugs thalidomide, bortezomib, and lenalidomide have each been approved for the treatment of this disease by targeting both multiple myeloma cells and the bone marrow microenvironment. Although benefit was first shown in relapsed and refractory disease, improved overall response, duration of response, and progression-free and overall survival can be achieved when these drugs are part of first-line regimens. This treatment framework promises to improve outcome not only for patients with multiple myeloma, but also with other haematological malignancies and solid tumours.

HPMA-based polymer conjugates with drug combination

Synthesis and physico-chemical behavior of new polymer-drug conjugates intended for the treatment of cancer were investigated. In the polymer conjugate with the expected dual therapeutic activity, two drugs, a cytostatic agent doxorubicin (DOX) and anti-inflammatory drug dexamethason (DEX) were covalently attached to the same polymer backbone via hydrolytically labile pH-sensitive hydrazone bonds. The precursor, a copolymer of N-(2-hydroxypropyl)methacrylamide (HPMA) bearing hydrazide groups randomly distributed along the polymer chain, was conjugated with DOX (through its C13 keto group) or with a keto ester (DEX). Two derivatives of DEX, 4-oxopentanoate and 4-(2-oxopropyl)benzoate esters, were synthesized and employed for conjugation reaction. As a control, also a few polymer conjugates containing only a single drug (DOX or DEX) attached to the polymer carrier were synthesized. Physico-chemical properties of the polymer conjugates strongly depend on the attached drug, spacer structure and the drug content. Polymer-drug conjugates incubated in buffers modeling intracellular environment released the drug (DOX) or a drug derivatives (DEX) at the rate significantly exceeding the release rate observed under conditions mimicking situation in the blood stream. Incubation of the DEX conjugates in a buffer containing carboxyesterase resulted in complete ester hydrolysis thus demonstrating susceptibility of the system to release free active drug in the two-step release profile.

Treatment of patients with myeloma with comorbid conditions: considerations for the clinician

Patients with multiple myeloma (MM) frequently present with serious comorbidities such as renal impairment and/or diabetes. Treatment of these patient subsets poses a greater challenge: renal dysfunction can alter drug clearance leading to increased toxicity, and commonly used regimens can induce or exacerbate hyperglycemia. In recent years, novel targeted therapies have broadened and improved treatment options for all patients with MM. With these advancements, clinical trials are beginning to report benefit in patients with renal impairment. Furthermore, steroid-sparing and steroid-free regimens have proven highly efficacious and are predicted to improve options for patients with diabetes. This review will highlight recent trials evaluating novel regimens that promise to improve the standard of care for patients with MM with significant comorbidity.

Pathogenesis and treatment of renal failure in multiple myeloma

Renal failure is a frequent complication in patients with multiple myeloma (MM) that causes significant morbidity. In the majority of cases, renal impairment is caused by the accumulation and precipitation of light chains, which form casts in the distal tubules, resulting in renal obstruction. In addition, myeloma light chains are also directly toxic on proximal renal tubules, further adding to renal dysfunction. Adequate hydration, correction of hypercalcemia and hyperuricemia and antimyeloma therapy should be initiated promptly. Recovery of renal function has been reported in a significant proportion of patients treated with conventional chemotherapy, especially when high-dose dexamethasone is also used. Severe renal impairment and large amount of proteinuria are associated with a lower probability of renal recovery. Novel agents, such as thalidomide, bortezomib and lenalidomide, have significant activity in pretreated and untreated MM patients. Although there is limited experience with thalidomide and lenalidomide in patients with renal failure, data suggest that bortezomib may be beneficial in this population. Clinical studies that have included newly diagnosed and refractory patients indicate that bortezomib-based regimens may result in rapid reversal of renal failure in up to 50% of patients and that full doses of bortezomib can be administered without additional toxicity.

Individualizing treatment of patients with myeloma in the era of novel agents

Progress in the understanding of multiple myeloma (MM) cell biology has led to the identification of new relevant prognostic factors and subsequently different risk groups. This concept, together with the recent discovery of new drugs with novel mechanisms of action, will probably lead to individualized treatment according to the different patients' characteristics. In this review, we focus on current available agents already approved for MM, and discuss individualized treatment approaches for both transplantation candidates (subdivided into standard and high-risk patients) and elderly patients. Future progress in MM will be based on using science to inform the design of the optimal combined treatments, and high throughput assays that can assess the ability of combination therapies to induce death of MM cells, both alone and in the bone marrow microenvironment.

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.

Management of relapsed and relapsed refractory myeloma

Studies of bortezomib, thalidomide, and lenalidomide have shown promising clinical activity in relapsed/refractory multiple myeloma (MM). Bortezomib alone and in combination with other agents is associated with high response rates, consistently high rates of complete response, and a predictable and manageable profile of adverse events. Thalidomide-based regimens have also shown substantial clinical activity. The accumulating experience from ongoing trials of bortezomib/lenalidomide/dexamethasone combinations in patients who have relapsed/refractory or newly diagnosed MM will provide critical information that will determine the possible role of this combination as the basic backbone for combination regimens for management of advanced MM.

New drugs for myeloma

Although multiple myeloma remains incurable with conventional treatments, management of the disease has recently been transformed with the introduction of three novel agents, bortezomib, thalidomide, and lenalidomide. The proteasome inhibitor bortezomib is approved for the treatment of patients who have received one prior therapy; there is a growing body of clinical evidence showing its effectiveness alone and in combination in the frontline setting, with high response rates and consistently high rates of complete response. Thalidomide plus dexamethasone is approved as frontline treatment of multiple myeloma. Other combination regimens including thalidomide have demonstrated substantial activity in both relapsed and frontline settings. Recently, the thalidomide analogue lenalidomide has been approved, in combination with dexamethasone, for the treatment of patients who have received one prior therapy; this regimen has shown promising results in the frontline setting. These agents represent a new generation of treatments for multiple myeloma that affect both specific intracellular signaling pathways and the tumor microenvironment. Other novel, targeted therapies are also being evaluated in preclinical and clinical studies. Regimens incorporating bortezomib, thalidomide, lenalidomide, and other novel agents, together with commonly used conventional drugs, represent a promising future direction in myeloma treatment. At present, further investigation is required to assess the safety and activity of combinations integrating these other novel agents. However, bortezomib, thalidomide, and lenalidomide are now in widespread clinical use. This review therefore focuses on the extensive clinical data available from studies of these drugs in the treatment of newly diagnosed and advanced multiple myeloma.

Current Standards for First-Line Therapy of Multiple Myeloma

Current standards of care for first-line treatment of multiple myeloma are evolving rapidly because of the introduction of regimens based on novel agents with unique mechanisms of action: the proteasome inhibitor bortezomib and the immunomodulatory drugs thalidomide and lenalidomide. These regimens are becoming increasingly widely used, offering substantially greater benefit to patients in terms of higher response rates and, more importantly, prolonged response durations and survival compared with established standard first-line treatment strategies. A notable aspect of many of these emerging treatment options is the very high rates of complete response (CR) reported, previously only seen with transplantation-based strategies. Achievement of CR is prognostic for improved overall survival; therefore, the higher rates and quality of responses seen with the new regimens might substantially improve patient outcomes versus established standards of care. For example, addition of each of the 3 novel agents to melphalan/prednisone results in higher overall response rates and CR rates, as well as prolonged progression-free and overall survival, compared with melphalan/prednisone alone. Similar substantial improvements in response are seen with addition of the 3 agents to single-agent dexamethasone and the use of bortezomib or thalidomide in VAD (vincristine/doxorubicin/dexamethasone)-like regimens, as induction therapies before stem cell transplantation and in patients not proceeding to transplantation. Ultimately, these novel regimens might obviate the need for stem cell transplantation in a sizeable proportion of patients. The emergence of these new therapeutic options appears likely to significantly alter the first-line treatment paradigm for patients with multiple myeloma.

The thalidomide saga

Over the past 50 years, thalidomide has been a target of active investigation in both malignant and inflammatory conditions. Although initially developed for its sedative properties, decades of investigation have identified a multitude of biological effects that led to its classification as an immunomodulatory drug (IMiD). In addition to suppression of tumor necrosis factor-alpha (TNF-alpha), thalidomide effects the generation and elaboration of a cascade of pro-inflammatory cytokines that activate cytotoxic T-cells even in the absence of co-stimulatory signals. Furthermore, vascular endothelial growth factor (VEGF) and beta fibroblast growth factor (bFGF) secretion and cellular response are suppressed by thalidomide, thus antagonizing neoangiogenesis and altering the bone marrow stromal microenvironment in hematologic malignancies. The thalidomide analogs, lenalidomide (CC-5013; Revlimid) and CC-4047 (Actimid), have enhanced potency as inhibitors of TNF-alpha and other inflammatory cytokines, as well as greater capacity to promote T-cell activation and suppress angiogenesis. Both thalidomide and lenalidomide are effective in the treatment of multiple myeloma and myelodysplastic syndromes for which the Food and Drug Administration granted recent approval. Nonetheless, each of these IMiDs remains the subject of active investigation in solid tumors, hematologic malignancies, and other inflammatory conditions. This review will explore the pharmacokinetic and biologic effects of thalidomide and its progeny compounds.

[New treatment of multiple myeloma]

PURPOSE

After decades of minimal progress, two new classes of drugs with novels mechanisms of action: immunomodulatory drugs (thalidomide and lenalidomide) and proteasome inhibitors (bortezomib) have shown great activity for the treatment of multiple myeloma.

CURRENT KNOWLEDGE AND KEY POINTS

Thalidomide acts by a variety of mechanisms; its efficacy is well known in disease relapse especially associated with dexamethasone. Recent results prove that combination of thalidomide with melphalan and prednisone should be considered as the first line standard of care in elderly patient. The main side effects are peripheral neuropathy and deep-vein thrombosis. Bortezomib is the first proteasome inhibitor. It is approved for the treatment in first disease relapse. The combination with glucocorticoids is synergistic. This combination in induction treatment before autologous stem cell transplantation is promising, as well as the combination with melphalan and prednisone in elderly patient. The main toxicities are fatigue and peripheral neuropathy. Lenalidomide is a structural analogue of thalidomide. Its efficacy in combination with dexamethasone has been proved in relapsing patients. The main toxicity is hematologic. Utilisation as first line treatment is also promising.

FUTURE PROSPECTS AND PROJECTS

These three drugs have toxicities predictable and manageable and can be used successively or in combination for greater effectiveness. They have an impact on the multiple myeloma treatment strategies and on the disease course itself.

International Society of Geriatric Oncology (SIOG) recommendations for the adjustment of dosing in elderly cancer patients with renal insufficiency

A SIOG taskforce was formed to discuss best clinical practice for elderly cancer patients with renal insufficiency. This manuscript outlines recommended dosing adjustments for cancer drugs in this population according to renal function. Dosing adjustments have been made for drugs in current use which have recommendations in renal insufficiency and the elderly, focusing on drugs which are renally eliminated or are known to be nephrotoxic. Recommendations are based on pharmacokinetic and/or pharmacodynamic data where available. The taskforce recommend that before initiating therapy, some form of geriatric assessment should be conducted that includes evaluation of comorbidities and polypharmacy, hydration status and renal function (using available formulae). Within each drug class, it is sensible to use agents which are less likely to be influenced by renal clearance. Pharmacokinetic and pharmacodynamic data of anticancer agents in the elderly are needed in order to maximise efficacy whilst avoiding unacceptable toxicity.

[Effectivity of thalidomide and dexamethasone for the treatment of refractory multiple myeloma: a retrospective study of 36 consecutive cases]

BACKGROUND AND OBJECTIVE

Multiple myeloma (MM) is a plasm-cell neoplasm characterized by a monoclonal protein in the serum or urine. Thalidomide is effective as second line treatment.

PATIENTS AND METHOD

We performed a retrospective study of 36 consecutive patients with refractory MM treated with thalidomide and dexamethasone as second line therapy, with the objective of analyzing the rate of response (primary end point), progression-free survival (PFS) and toxicity profiles (second end points).

RESULTS

In our study the overall response rate was 55.6%, with a median of PFS of 12.6 months (95% confidence interval: 4-21 months). PFS at 6, 12 and 18 months was 61.11%, 50% and 22.22% respectively. 30.6% of the patients had neuropathy, 11.11% had rash and 5.55% had deep vein thrombosis.

CONCLUSIONS

The combination of thalidomide and dexamethasone is an effective and safe second line treatment for refractory MM, with a manageable toxicity.

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.

The treatment of relapsed and refractory multiple myeloma

Relapsed and refractory multiple myeloma (MM) constitutes a specific and unmet medical need. Median survival ranges from as little as 6 to 9 months, and responses to treatment are characteristically short. Patients with relapsed/refractory disease are defined as those who, having achieved minor response or better, relapse and then progress while on salvage therapy, or experience progression within 60 days of their last therapy. In the era prior to the development of novel biologically based therapies for MM, relapse from successive treatment regimens resulted in progressively shorter response durations, which typically reflected emerging drug resistance, as well as changes in disease biology within each patient, with tumor cells expressing a more aggressive phenotype, higher proliferative fraction and lower apoptotic rates. Both bortezomid- and lenalidomide-based therapies are expecially active, with bortezomib in particular being shown to provide a platform for combinations able to overcome resistance in this setting. The addition of novel and conventional agents to the treatment backbone of lenalidomide, thalidomide, and bortezomib are areas of active study, with participation in clincial trials a clear priority for such patients. Clinical challenges in the relapsed/refractory population include light chain and IgA isotype, renal failure, extramedullary disease, hyposecretory myeloma, and advanced bone disease.

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.

Long-term results of thalidomide in refractory and relapsed multiple myeloma with emphasis on response duration

OBJECTIVE

Thalidomide administered as a single agent produces a response rate of about 40% in patients with refractory or relapsed multiple myeloma (MM). The aim of our study was to determine the quality and duration of such responses.

PATIENTS AND METHODS

Forty-two consecutive patients with refractory (20) or relapsed (22) MM were given thalidomide as a single agent at our institution. Most of them (70%) had previously received two or more lines of therapy, and 38% had undergone autologous stem cell transplantation.

RESULTS

Eighteen patients (43%) responded to thalidomide [11 minimal responses (MR) and seven partial responses (PR)] according to the European Marrow Transplant Registry (EBMT) criteria. The median time to response was 3 months and the median duration of therapy in responding patients was 9 months. Treatment was discontinued because of toxicity in 10 responding patients. The toxicity mainly led to peripheral neuropathy and fatigue. At the time of this analysis, all responding patients had progressed except one who remains in continued stable PR. The median time to progression was 15.6 months (range 1.3 to 70+), with a trend towards a longer duration for patients who achieved PR vs. MR (21.2 vs. 11.2 months, P = 0.11). The median duration of response was 12.4 months (range: 0.3-67+) (17.2 months for PR vs. 9.7 months for MR, P = 0.11).

CONCLUSION

These results show that the effect of thalidomide in refractory/relapsed MM can be sustained, particularly in patients who achieve a greater degree of response, and support the finding that this drug can be used for maintenance therapy.

Bortezomib-dexamethasone combination in a patient with refractory multiple myeloma and impaired renal function

BACKGROUND

Multiple myeloma (MM) is a hematologic neoplasia characterized by the monoclonal proliferation of bone marrow plasma cells. Renal failure occurs in 20% to 30% of MM patients at diagnosis and in >50% with an advanced form of the disease. For those with advanced MM, often a high-risk group of patients with poor prognosis, salvage treatment for renal failure needs to avoid nephrotoxic drugs.

CASE SUMMARY

We report a case of a 78-year-old white male (weight, 90 kg) presented to the Department of Medical Oncology and Hematology, Istituto Clinico Humanitas, Rozzano, Milan, Italy, with refractory MM immunoglobulin G kappa (IgGkappa), Durie-Salmon Stage IIA, with progressive renal failure after an oral melphalan, prednisone, and thalidomide regimen (4 mg/m2.d, 40 mg/m2.d for 7 days every 6 weeks, and 100 mg/d, respectively). The patient had documented increments of serum monoclonal component (M-protein), anemia, and renal failure with Bence Jones proteinuria (serum creatinine, 2.9 mg/dL; creatinine clearance, 30 mL/min; hemoglobin, 10.9 g/dL; serum IgGkappa M-protein, 3.9 g/dL; proteinuria 3.5 g/d;light-chain level in urine, 1.2 g/L). After 2 cycles with bortezomib at a reduced dose (1.0 mg/m2 twice weekly for 2 weeks followed by a 10-day rest period) to evaluate tolerability and renal toxicity, the patient completed another 3 cycles at the standard dose (1.3 mg/m2) in combination with dexamethasone (20 mg on the day of bortezomib administration and the day after). This led to an improvement of the renal function with a reduction of serum and urinary M-protein (serum creatinine 1.4 mg/dL; serum IgGkappa M-protein, 2.9 g/dL; proteinuria, 2 g/d; kappa light-chain level in urine, 0.7 g/L). The patient developed thrombocytopenia but did not suffer from some of the more severe adverse events associated with bortezomib, such as infection or peripheral neuropathy, even at full dose.

CONCLUSION

We report an elderly patient with refractory MM and progression with renal failure who responded to bortezomib treatment. Bortezomib was well tolerated in this patient.

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.

Treatment paradigms for the newly diagnosed patient with multiple myeloma

The management of newly diagnosed multiple myeloma is currently being revolutionized by the emergence of novel therapeutic agents. Thalidomide, the thalidomide analogue lenalidomide, and the proteasome inhibitor bortezomib each have potential roles to play in the initial therapy of myeloma that are supported by encouraging clinical trials results. While evaluation for stem cell transplantation (SCT) remains a part of the algorithm for management of the newly diagnosed patient, these drugs offer improved options for induction before, and possibly maintenance after, SCT. For the patient who is not a candidate for SCT the armamentarium for management has been significantly expanded. This review will summarize currently available data regarding these exciting agents and will describe therapeutic strategies currently on the horizon.

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.

Combination Therapy with Thalidomide, Incadronate, and Dexamethasone for Relapsed or Refractory Multiple Myeloma

The feasibility and efficacy of a combination of thalidomide, incadronate, and dexamethasone (TID) were studied in 12 patients with relapsed or refractory multiple myeloma. The protocol, consisting of 300 mg/day of thalidomide administered orally, intravenous incadronate (10 mg/day) administered weekly, and 12 mg/day dexamethasone for 4 days, was repeated every 3 weeks. Evaluations of efficacy and toxicity were carried out every 3 weeks and were continued for 3 cycles. Three patients were excluded during the study because of apnea, severe somnolence, and pancytopenia. Of 9 evaluated patients, the partial responses achieved in 3 patients and the minor responses achieved in 4 patients corresponded to a response rate of 78% according to the criteria of the European Group for Blood and Marrow Transplantation. In addition, painful osteolytic symptoms improved rapidly after 1 cycle of TID therapy in the 10 patients evaluated. These data suggest that TID is a feasible and promising therapeutic approach for refractory and relapsed multiple myeloma.

Phase II study of G3139, a Bcl-2 antisense oligonucleotide, in combination with dexamethasone and thalidomide in relapsed multiple myeloma patients

PURPOSE

Bcl-2 regulates the mitochondrial apoptosis pathway that promotes chemotherapy resistance. Bcl-2 antisense oligonucleotide, G3139, targets Bcl-2 mRNA.

PATIENTS AND METHODS

G3139 was administered (3 to 7 mg/kg/d for 7 days) by continuous intravenous infusion. On day 4, patients started thalidomide (100 to 400 mg as tolerated) and dexamethasone (40 mg daily for 4 days) on 21-day cycles for three cycles. Stable and responding patients continued on 35-day cycles for 2 years.

RESULTS

Thirty-three patients (median age, 60 years; range, 28 to 76 years) received 220 cycles. Patients received a median of three prior regimens including thalidomide (n = 15) and stem-cell transplantation (n = 31). The regimen was well tolerated; the median number of cycles per patient was eight (range, one to 16+ cycles). Toxicities included reversible increase in creatinine, thrombocytopenia, neutropenia, fatigue, anorexia, constipation, fever, neuropathy, edema, electrolyte disturbances, and hyperglycemia. Fifty-five percent of patients had objective responses, including two complete responses (CRs), four near CRs (positive immunofixation), and 12 partial responses; six patients had minimal responses (MRs). Of patients who received prior thalidomide, seven had objective responses, and three had MRs. The median duration of response was 13 months, and estimated progression-free and overall survival times were 12 and 17.4 months, respectively. Responding patients had significant increase in polyclonal immunoglobulin M (P = .005), indicating innate immune system activation. Western blot analysis of Bcl-2 protein isolated from myeloma cells before and after G3139 demonstrated a decrease of Bcl-2 levels in three of seven patients compared with six of nine patients using reverse transcriptase polymerase chain reaction.

CONCLUSION

G3139, dexamethasone, and thalidomide are well tolerated and result in encouraging clinical responses in relapsed multiple myeloma patients.

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.

The combination of intermediate doses of thalidomide and dexamethasone reduces bone marrow micro-vessel density but not serum levels of angiogenic cytokines in patients with refractory/relapsed multiple myeloma

The aim of the study was the evaluation of anti-angiogenic activity of the combination of intermediate doses of thalidomide and dexamethasone in patients with refractory/relapsed myeloma. Twenty-five patients were included in the study. Microvessel density (MVD) was evaluated in marrow biopsies before and after treatment. Serum levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (b-FGF), tumor necrosis factor-alpha (TNF-alpha), which have angiogenic potential and interleukin-6 (IL-6), IL-1beta, soluble IL-6 receptor (sIL-6R), and transforming growth factor-beta (TGF-beta) which are involved in the disease biology, were measured before treatment and then every 2 weeks for 8 weeks. Pretreatment levels of MVD, VEGF, b-FGF, IL-6, sIL-6R were increased in the patients compared to controls. The overall response rate to therapy was 72%. The administration of the combined regimen produced a significant reduction in MVD in responders. However, an increase in serum levels of VEGF, b-FGF, IL-6, sIL-6R was observed post-treatment in responders. In contrast, serum levels of TNF-alpha, TGF-beta, IL-1beta did not differ between patients and controls and remained unchanged during the study. These results suggest that the combination of thalidomide plus dexamethasone is an effective treatment for myeloma reducing MVD marrow levels but not serum levels of angiogenic cytokines or cytokines implicated in myeloma biology.