Therapy with thalidomide in refractory multiple myeloma patients - the revival of an old drug

Cancer Chemotherapy-Induced Sinus Bradycardia: A Narrative Review of a Forgotten Adverse Effect of Cardiotoxicity

Cardiotoxicity is a common adverse effect of anticancer drugs (ACDs), including the so-called targeted drugs, and increases morbidity and mortality in patients with cancer. Attention has focused mainly on ACD-induced heart failure, myocardial ischemia, hypertension, thromboembolism, QT prolongation, and tachyarrhythmias. Yet, although an increasing number of ACDs can produce sinus bradycardia (SB), this proarrhythmic effect remains an underappreciated complication, probably because of its low incidence and severity since most patients are asymptomatic. However, SB merits our interest because its incidence increases with the aging of the population and cancer is an age-related disease and because SB represents a risk factor for QT prolongation. Indeed, several ACDs that produce SB also prolong the QT interval. We reviewed published reports on ACD-induced SB from January 1971 to November 2020 using the PubMed and EMBASE databases. Published reports from clinical trials, case reports, and recent reviews were considered. This review describes the associations between ACDs and SB, their clinical relevance, risk factors, and possible mechanisms of onset and treatment.

Stem Cell Transplantation for Multiple Myeloma

BACKGROUND

Multiple myeloma (MM) is the second most common hematologic malignancy, affecting approximately 14,000 new patients in the United State per year. The median overall survival is 5 years, and cure is a realistic goal for only a small minority of patients.

METHODS

A review of the literature was conducted that focused on treatment strategies for MM involving administration of high doses of chemotherapy followed by autologous or allogeneic hematopoietic stem cell transplant.

RESULTS

For over three decades, the standard treatment for MM has been a regimen of melphalan and prednisone (MP). Complete responses (CRs) have been rare, and 50% of patients have had disease that was resistant to treatment with MP. Attempts have been made to improve the outcome of MM by administering other combinations of standard doses of chemotherapy, but these treatments are equivalent in terms of overall survival. For patients who are candidates, high-dose therapy followed by autologous stem cell transplantation results in higher CR rates and improved long-term survival compared to treatment with standard doses of chemotherapy alone. While this strategy represents an advance in the treatment of MM, evidence-based reviews indicate that there are a number of issues to consider regarding the induction therapy, the collection of stem cells, and the timing, type, and number of high-dose therapies to use in this type of treatment strategy.

CONCLUSIONS

Advances have been made in autologous transplantation, allogeneic transplantation, anti-MM agents, and immunotherapy for MM. Combining these different strategies to achieve synergistic responses is an exciting possibility.

Overview of drug therapy for multiple myeloma

Background. Multiple myeloma accounts for 10% of all haematologic malignancies worldwide. In Europe, over 10 000 new cases and nearly 8000 deaths were attributed to multiple myeloma in 2000. Unlike other malignancies, in which surgery and radiation are important treatment modalities, myeloma is exclusively treated with stem cell transplantation and drug therapy, requiring pharmacists to stay abreast of new developments. The melphalan-prednisolone and vincristine-doxorubicin-dexamethasone (VAD) regimens, which have been standard treatments for multiple myeloma over the past few decades, have yielded responses without real survival benefits. Transplantation utilizing high-dose chemotherapy has produced the only meaningful survival benefits for patients with multiple myeloma, but many patients are not candidates for this aggressive treatment option. More effective therapies for multiple myeloma are needed.

Objective. To address the mechanisms of action, safety, and efficacy of novel approaches to the treatment of myeloma involving bortezomib, thalidomide and its analogues, lenalidomide and CC-4047 (ActimidTM), and arsenic trioxide as single agents or in combination regimens.

Data sources. Published preclinical and primary clinical trial results, as well as scientific or clinical meeting abstracts. The author determined the relevance and subsequent inclusion of the data.

Conclusions. Bortezomib is approved in the US and Europe as single-agent therapy for the treatment of relapsed or refractory multiple myeloma. Thalidomide, its analogues, and arsenic trioxide have demonstrated activity and are under investigation in this disease. Further clinical trials of the efficacy and toxicity of these novel agents are ongoing and will further define optimal combinations and sequencing with conventional therapies.

Optimizing the treatment of patients with multiple myeloma and renal impairment

Renal impairment is a common complication of multiple myeloma. It is found in about 20% to 25% of patients at diagnosis and in ≤ 50% at some point during the disease course. The presence of renal insufficiency diminishes patients' quality of life and has been associated with increased mortality, although the outcomes of patients after successful induction therapy have been comparable to those with normal renal function. Therefore, the treatment of patients with multiple myeloma and renal impairment is a major challenge and should aim to achieve remission in a large proportion of patients. New drugs introduced to treat multiple myeloma during the past decade have an established place in the treatment of patients with renal failure. Bortezomib appears to be most beneficial in this setting and, combined with other drugs, provides a chance for rapid remission and related improvement of renal function. Immunomodulatory drugs such as thalidomide and lenalidomide have also been used successfully in patients with renal insufficiency, although for the latter drug appropriate dose adjustments are necessary. The presence of renal failure is not a contraindication to autologous bone marrow transplantation in patients eligible for this procedure. Among the classic cytotoxic agents, bendamustine, in particular, should be considered for patients with renal insufficiency. Appropriate supportive care is also extremely important in the treatment of patients with multiple myeloma and renal failure. It can include plasmapheresis and removal of free light chains with high cut-off hemodialysis, adapted dosages of bisphosphonates, and avoidance of drugs and conditions that can impair renal function.

A case of extramedullary plasmablastic plasmacytoma successfully treated using a combination of thalidomide and dexamethasone and a review of the medical literature

A 56-year-old man developed epistaxis, hoarseness, and swelling of a finger in March 2010. On the basis of biopsies of the masses in the pharynx and finger, he was diagnosed with extramedullary plasmablastic plasmacytoma, with somewhat immature CD45(+), MPC-1(-), and CD49e(-). CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) and VCAP (vincristine, cyclophosphamide, doxorubicin, and prednisolone) therapy was ineffective, but combination therapy with thalidomide and dexamethasone was highly effective. Thalidomide monotherapy successfully maintained partial remission for approximately 7 months. A mass appeared in the right neck in February 2011, and a biopsy confirmed recurrence. Changes to CD45 negativity and MPC-1 partial positivity were seen, while CD49e negativity persisted, suggesting that the plasmablastic plasmacytoma had reverted to a more immature state. Bortezomib therapy was started in March 2011 and was effective. However, during the second round of treatment, the patient developed acute lung injury, which was improved by steroid pulse therapy. After the discontinuation of bortezomib, the extramedullary mass increased rapidly, and the patient died of multiple organ failure. An autopsy showed that plasmablastic plasmacytomas had infiltrated into multiple organs. Extramedullary plasmacytomas and those that revert to an immature state are associated with a poor prognosis, so further treatment improvements are needed in the future.

Choosing treatment options for patients with relapsed/refractory multiple myeloma

Multiple myeloma (MM) is a clonal plasma cell disorder that is still incurable using conventional treatments. Over the last decade, advances in front-line therapy have led to an increase in survival, but there are still some doubts in the case of relapsed/refractory disease. We searched the PubMed database for articles on treatment options for patients with relapsed/refractory MM published between 1996 and 2013. These treatments included hematopoietic cell transplantation (HCT), rechallenges using previous chemotherapy regimens, and trials of new regimens. The introduction of new agents such as the immunomodulatory drugs (IMIDs) thalidomide and lenalidomide, and the first-in-its-class proteasome inhibitor bortezomib, has greatly improved clinical outcomes in patients with relapsed/refractory MM, but not all patients respond and those that do may eventually relapse or become refractory to treatment. The challenge is therefore to select the optimal treatment for each patient by balancing efficacy and toxicity. To do this, it is necessary to consider disease-related factors, such as the quality and duration of responses to previous therapies, and the aggressiveness of the relapse, and patient-related factors such as age, comorbidities, performance status, pre-existing toxicities and cytogenetic patterns. The message from the trials reviewed in this article is that the new agents may be used to re-treat relapsed/refractory disease, and that the sequencing of their administration should be modulated on the basis of the various disease and patient-related factors. Moreover, our understanding of the pharmacology and molecular action of the new drugs will contribute to the possibility of developing tailored treatment.

Angiogenesis and hematological malignancies

Since the initial hypotheses on the importance of angiogenesis in the pathogenesis of cancer approximately 30 years ago, there have been major advances in the understanding of the cellular and molecular mechanisms involved in the regulation of this complex process of new vessel formation. Among the multitude of factors, vascular endothelial growth factor (VEGF) has emerged as one of the most potent angiogenic factors, being implicated in the initiation of signal transduction responsible for cell proliferation, survival, migration and adhesion. Inhibition of VEGF and its signaling pathway offers a potential new molecular target in cancer therapy. This article reviews the role of angiogenesis and its mediators, particularly vascular endothelial growth factors, in hematological malignancies, as well as the potential use of anti-angiogenic therapies in the management of these conditions.

Thalidomide Effects in the Post-transplantation Setting in Patients with Multiple Myeloma

Thalidomide recently has been proven to have an impact on plasma cell dyscrasia through multiple mechanisms. Its effects on hematopoietic stem cells both in harvesting and in the immediate post-transplant setting are still unknown. We report on 12 cases (9 males and 3 females), median age 56 years old (range 41-65 years old) who underwent autologous peripheral stem cell transplantation for multiple myeloma and received thalidomide as maintenance therapy post-transplantation. Patients received various cytoreductive therapies prior to stem cell harvest. Eleven patients were in partial remission (PR) and one in complete remission (CR) on entry into the transplant phase of therapy. The median CD34+/kg harvested was 4.7 x 10(6) (range 1.9-55.4 x 10(6) CD34+/kg). All patients received intravenous melphalan 200 mg/m2 as their conditioning regimen. Six of twelve patients attained a CR post-transplant, and six a PR. Thalidomide was started after all patients engrafted post-transplant (absolute neutrophil count >0.5 x 10(9)/l and self-sustained platelet count >20 x 10(9)/l) and following satisfactory resolution of transplant toxicity including mucositis and diarrhea. Thalidomide was initiated at a median of 43 days post-transplant (range 23-138 days). The median leukocyte and platelet counts at the moment of thalidomide initiation were 5.8 x 10(9)/l (range 2.9-8.6 x 10(9)/l) and 196 x 10(9)/l (range 30-351 x 10(9)/l), respectively. Thalidomide was started at 100 mg daily, increasing 100 mg/day/month until reaching a dose of 400 mg/day. One patient failed to tolerate thalidomide due to CNS symptoms and stopped therapy at 12 days. Another patient stopped thalidomide therapy after 71 days, because of severe fatigue secondary to hypothyroidism. The most common adverse effects were constipation (5), rash (4), dry skin (3) and dizziness (3). No grade 3-4 adverse effects were documented. Neutropenia, previously reported as an adverse effect in this setting, was not seen to date in our cohort. All patients attained a CR or PR after transplant and thalidomide maintenance. We have had two relapses during a median follow-up of 68 weeks (range 42-172 weeks).

CONCLUSION

Thalidomide appears to be a safe drug in the post-transplant setting, perhaps adding to the response achieved post-transplant without major toxicity. Longer follow up and future randomized trials will be needed to validate the role of thalidomide and its long-term effect when used as maintenance therapy in the post-transplant setting.

Current and emerging treatment options for patients with relapsed myeloma

Multiple myeloma (MM) is a neoplastic disorder. It results from proliferation of clonal plasma cells in bone marrow with production of monoclonal proteins, which are detectable in serum or urine. MM is clinically characterized by destructive bone lesions, anemia, hypercalcemia and renal insufficiency. Its prognosis is severe, with a median survival after diagnosis of approximately 3 years due to frequent relapses. Treatments for patients with relapsed/refractory MM include hematopoietic cell transplantation, a rechallenge using a previous chemotherapy regimen or a trial of a new regimen. The introduction of new drugs such as thalidomide, lenalidomide and bortezomib has markedly improved MM outcomes. When relapse occurs, the clinician's challenge is to select the optimal treatment for each patient while balancing efficacy and toxicity. Patients with indolent relapse can be first treated with a 2-drug or a 3-drug combination. Patients with more aggressive relapse often require therapy with a combination of multiple active agents. Autologous stem cell transplantation should be considered as salvage therapy at first relapse for patients who have cryopreserved stem cells early in the disease course. The aim of this review is to provide an overview on the pharmacological and molecular action of treatments used for patients with relapsed/refractory multiple myeloma.

Management of myeloma-associated renal dysfunction in the era of novel therapies

Multiple myeloma (MM) is a plasma cell neoplasm often associated with renal impairment (RI), with myeloma cast nephropathy recognized as the most common cause. While RI is present in over 50% of MM patients at some point in their disease course, it is associated with higher tumor burden, more aggressive disease, diminished quality of life, development of complications and increased mortality. The introduction of novel therapies, including bortezomib, lenalidomide and thalidomide, has revolutionized the management of MM. They are now considered first-line therapies in induction, maintenance and salvage therapy for MM. In addition to their anti-MM effect, they can improve outcome in patients with RI, especially when combined, and bortezomib with dexamethasone may have a renal protective effect. This review focuses on the use of these agents in patients with MM and RI, and evaluates their efficacy, safety, need for dose adjustment and impact on RI.

Aminoglycoside-associated Severe Renal Failure in Patients with Multiple Myeloma Treated with Thalidomide

Thalidomide has been proved to play an important role in rescue treatment of patients with refractory/relapsed multiple myeloma (MM). However, thalidomide therapy is associated with numerous side effects, mainly somnolence, constipation, fatigue or peripheral neuropathy. We report three patients diagnosed with MM and treated with thalidomide as salvage therapy who developed severe renal failure when they received aminoglycoside antibiotics. This observation suggests that thalidomide can potentiate nephrotoxicity of aminoglycoside antibiotics in patients with MM.

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.

Toxicity profile of the immunomodulatory thalidomide analogue, lenalidomide: phase I clinical trial of three dosing schedules in patients with solid malignancies

Thalidomide is an anti-angiogenic agent currently used to treat patients with malignant cachexia or multiple myeloma. Lenalidomide (CC-5013) is an immunomodulatory thalidomide analogue licensed in the United States of America (USA) for the treatment of a subtype of myelodysplastic syndrome. This two-centre, open-label phase I study evaluated dose-limiting toxicities in 55 patients with malignant solid tumours refractory to standard chemotherapies. Lenalidomide capsules were consumed once daily for 12 weeks according to one of the following three schedules: (I) 25 mg daily for the first 7 d, the daily dose increased by 25 mg each week up to a maximum daily dose of 150 mg; (II) 25mg daily for 21 d followed by a 7-d rest period, the 4-week cycle repeated for 3 cycles; (III) 10 mg daily continuously. Twenty-six patients completed the study period. Two patients experienced a grade 3 hypersensitivity rash. Four patients in cohort I and 4 patients in cohort II suffered grade 3 or 4 neutropaenia. In 2 patients with predisposing medical factors, grade 3 cardiac dysrhythmia was recorded. Grade 1 neurotoxicity was detected in 6 patients. One complete and two partial radiological responses were measured by computed tomography scanning; 8 patients had stable disease after 12 weeks of treatment. Fifteen patients remained on treatment as named patients; 1 with metastatic melanoma remains in clinical remission 3.5 years from trial entry. This study indicates the tolerability and potential clinical efficacy of lenalidomide in patients with advanced solid tumours who have previously received multi-modality treatment. Depending on the extent of myelosuppressive pre-treatment, dose schedules (II) or (III) are advocated for large-scale trials of long-term administration.

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.

A systematic review of phase-II trials of thalidomide monotherapy in patients with relapsed or refractory multiple myeloma

The activity of thalidomide in relapsed or refractory multiple myeloma is widely accepted but not yet demonstrated in a randomised-controlled trial. A systematic review of the published clinical trials of these patients could reduce the possible bias of single phase-II studies. A systematic search identified 42 communications reporting on 1674 patients. Thirty-two trials used an escalating dosing regimen and four a fixed dose regimen (one dose with 50 mg/d, three doses with 200 mg/d). The target dose in the dose escalating trials was 800 mg/d in 17 trials, 400-600 mg/d in 10 and 200 mg/d in one trial. The intention-to-treat population for efficacy was 1629 patients with a median age of 62 years. The complete and partial (>50% reduction in monoclonal protein) response rate was 29.4% (95%-confidence interval, 27-32%). The rates for minor responses or stable disease were 13.8% (12-16%) and 11.0% (9-13%). Progressive disease was reported in 9.9% (8-11%). The median overall survival from all trials was reported at 14 months. Severe adverse events (grade III-IV) included somnolence 11%, constipation 16%, neuropathy 6%, rash 3%, thrombo-embolism 3%, cardiac 2%. In conclusion, thalidomide monotherapy achieved complete and partial responses in 29.4% of patients with relapsed or refractory multiple myeloma.

Lovastatin and thalidomide have a combined effect on the rate of multiple myeloma cell apoptosis in short term cell cultures

OBJECTIVE

Multiple myeloma is characterized by an accumulation of plasma cells in bone marrow. Despite many therapeutic regimens introduced recently, the prognosis for patients suffering from treatment-resistant or relapsing multiple myeloma is still very poor. Thus, there is an urgent medical need for novel innovative drugs. Thalidomide is successfully used in resistant or relapsing myeloma patients, being reported to induce apoptosis or G1 growth arrest of myeloma cells and to regulate microvessel density and cytokine secretion. Lovastatin, largely used for the treatment of hypercholesterolemia, is another promising drug in multiple myeloma. High doses of lovastatin have been shown to have antiproliferative effect by inhibition of malignant cell proliferation and inducing programmed cell death.

METHODS

In this study, we tried to assess whether thalidomide and lovastatin had a combined effect on apoptosis of myeloma cells. We analyzed apoptosis induced by mixture of these two drugs in short-term cell culture of myeloma plasmocytes. To assess apoptosis, we used Annexin V and propidium iodide binding. We also examined the regulation of BCL-2 and BAX protein expression in the population of CD138+ plasmocytes. The cells were analyzed with the use of flow cytometry technique. The experiments were done before and after 72 h of cell culture.

RESULTS

We detected a higher rate of apoptosis induced by lovastatin and thalidomide mixture in comparison to apoptosis induced by lovastatin or thalidomide alone. In most patients, the BCL-2/BAX ratio was lower in cell cultures supplemented with mixture of lovastatin and thalidomide in comparison with cell cultures supplemented with lovastatin or thalidomide alone.

CONCLUSION

Based on our research we conclude that the mixture of lovastatin and thalidomide may increase the rate of multiple myeloma cells apoptosis in comparison to the single drug and the precise mechanism of this effect should be approved by further research.

Synthesis and evaluation of 4-[18F]fluorothalidomide for the in vivo studies of angiogenesis

In this study, we prepared 2-(2,6-dioxopiperidin-3-yl)-4-[(18)F]fluoroisoindole-1,3-dione (4-[(18)F]fluorothalidomide; [(18)F]1) for the in vivo studies of angiogenesis. Radiochemical synthesis of [(18)F]1 was carried out by labeling 4-trimethylammoniumthalidomide trifluoromethanesulfonate with nBu(4)N[(18)F]F in dimethyl sulfoxide (DMSO), followed by reverse-phase HPLC purification. Decay-corrected radiochemical yield of [(18)F]1 was 50-60%, with an effective specific activity of 42-120 GBq/micromol (end of synthesis). Incubation of the radioligand with human umbilical vein endothelial cells (HUVEC-C; American Type Culture Collection) showed a time-dependent increase in the uptake of the radioligand, and the uptake was inhibited by 8-11% in the presence of 10 microM thalidomide, indicating nonspecific binding of the radioligand. Positron emission tomography (PET) images of mice implanted with tumors in their right flanks revealed a marked accumulation of radioactivity in the livers, kidneys and bladders of the mice, and brain uptake appeared at approximately 40 min after injection. However, no radioactivity uptake was detected in the implanted tumor. Thin-layer chromatography (TLC), HPLC and LC-MS analyses of mouse liver microsomal metabolites of [(18)F]1 and 1 with or without nicotinamide adenine dinucleotide phosphate (NADPH) clearly revealed that the radioligand did not go through metabolic activation but underwent nonenzymatic hydrolysis at physiological pH. Therefore, these results would appear to indicate that [(18)F]1 may not be suitable for the in vivo studies of angiogenesis at least in mice, although it was reported that thalidomide and/or its hydrolysis products may be responsible for its activity in humans.

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.

Targeted therapy in multiple myeloma

BACKGROUND

Multiple myeloma (MM) is an incurable malignancy. Recent insights into its biology has allowed the use of novel therapies targeting not only the deregulated intracellular signaling in MM cells but also its interaction with the bone marrow microenvironment that confers drug resistance, growth, and survival advantage to the malignant cells.

METHODS

We review and summarize the recent advances in our knowledge of myeloma biology as well as the mechanism of action and clinical efficacy for novel therapeutic agents in clinical trials.

RESULTS

Several novel therapeutic agents are currently in clinical trials. Thalidomide is already established for both initial and salvage treatment. Bortezomib is being tested alone and in combination with conventional chemotherapy in various settings. Other agents are less effective in producing response but have been able to stabilize disease in patients with relapsed and/or refractory disease, such as arsenic trioxide, farnesyltransferase inhibitors, 2-methoxyestradiol, and vascular endothelial growth factor receptor inhibitors. Insights into drug resistance mechanism have also led to the development of novel agents that sensitize myeloma cells to chemotherapy (Bcl-2 antisense). Gene expression studies have in many instances identified pathways other than the intended target of the drug and have provided insights into the therapeutic mechanisms.

CONCLUSIONS

In the future, patients with MM will have more therapeutic options available than ever before. The challenge will be to identify patient subgroups that will benefit most from the different therapies and then determine how these biologically based therapies could be combined and incorporated into the overall management of patients.

Plasmacytoma relapses in the absence of systemic progression post-high-dose therapy for multiple myeloma

Autologous (ASCT) and allogeneic stem cell transplantations (alloBMT) are well-established therapies for multiple myeloma. However, patients continue to relapse at a constant rate. We present here 15 out of 163 patients who underwent SCT and relapsed with plasmacytomas only without evidence of bone marrow disease progression (14/147 post-ASCT and 1/16 post-alloBMT). The median time from SCT to plasmacytoma relapse was 24 months. The sites of plasmacytoma included bone, skin, rectum, and testicles. Five patients were treated with local radiotherapy, while seven patients received a combination of radiotherapy and chemotherapy or thalidomide, and two patients received chemotherapy alone with or without thalidomide. The recipient of alloBMT was initially treated with VAD-chemotherapy and local radiotherapy followed by a mini-allograft from the original donor. Eleven patients died at a median of 10 months following diagnosis of the plasmacytoma. Four are still alive, 12-20 months post-plasmacytoma diagnosis. These cases of unconventional disease recurrence are likely to be seen due to sub-clinical seeding of tumour cells suggestive of the presence of an extramedullary (EM) clone of plasma cells with a high degree of chemoresistance. We also review all the available data in the literature for the optimal therapy for patients with isolated EM relapse.

An evaluation of factors predicting long-term response to thalidomide in 234 patients with relapsed or resistant multiple myeloma

The aim of this study was to assess the prognostic value of pretreatment clinical and laboratory parameters in refractory or relapsed multiple myeloma (MM) patients who have a long-term response to thalidomide (THAL), lasting at least 18 months. The study was carried out on 234 patients who received THAL for relapsed/refractory myeloma. Out of the 234 patients, 129 patients (55.1%) responded to THAL with a mean response duration of 11.9 months (ranging from 1 to 48) and an overall survival rate of 20.3 months (ranging 1–55 months). In 64 patients (27.4% of the whole group), the response to THAL lasted ⩾18 months with a mean response lasting 24 months. Statistical analysis of the group of nonresponders and patients with long-term response to THAL showed a significantly higher serum albumin level (P=0.0003) and haemoglobin level (P=0.05), as well as a lower β2 microglobulin (β2M) (P=0.022), LDH (P=0.045) serum level in patients with long-term response. In this study, the LDH and serum albumin level were predictors for response to THAL therapy. The β2M serum level was not a predictor for response to THAL. The albumin serum level was the best parameter distinguishing the group of patients with long-term response to THAL from the entire responding group (P=0.02).

Thalidomide : mécanismes d'action et indications en hématologie

Purpose. - Thalidomide, a major teratogen drug, was rehabilitated mainly in malignant hemopathy. Current knowledge and key points. - Thalidomide-mechanisms of action are well known, multiple, they combine immunomodulatory, antiangiogenic properties, and the modulation of cytokines, particularly tumour necrosis factor-alpha. Multiple trials are ongoing, however, the main indication remain multiple myeloma with a response rate of 30% in relapsed patients. Future prospects and projects. - New structural analogues of the thalidomide which priviligiate some of the thalidomide-specific mechanisms of action, the selected cytokine inhibitory drugs (SelCIDS) and the immunomodulatory drugs (IMiDs) family are under evaluation. The IMiDs, which mechanism is based on stimulation of T lymphopoiesis rather than inhibition of tumour necrosis factor-alpha, are under clinical trials in multiple myeloma with interesting results.

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

The present study aimed to evaluate the side-effects and efficacy of thalidomide in combination with an anthracycline-containing chemotherapy regimen in previously untreated myeloma patients. Thalidomide (400 mg/d) was combined with bolus injections of vincristine and epirubicin and oral dexamethasone (VED). Chemotherapy cycles were repeated every 3 wk until no further reduction in myeloma protein was observed, whereas the treatment with thalidomide was continued until disease progression. Thirty-one patients were enrolled, 12 patients were exclusively treated with thalidomide in combination with VED and 19 patients additionally received high-dose melphalan, for consolidation. Adverse events and response to therapy were assessed prior to treatment with high-dose chemotherapy. Response to thalidomide combined with VED was complete remission in six patients (19%), partial remission in 19 patients (61%), stable disease in five patients (16%), and progressive disease in one patient (3.2%). Grade 3 and 4 adverse events consisted of leukocytopenia in 10 patients (32%), and thrombocytopenia and anemia in one patient each (3.2%). Neutropenic infections grade 3 and 4 occurred in seven (23%) and three patients (9.7%), respectively, including two patients (6.5%) who died from septic shock. Deep vein thrombosis occurred in eight patients (26%), constipation in 20 patients (65%), and polyneuropathy in 20 patients (65%). The probability of event-free survival and overall survival in the whole group of patients at 36 months were 26 and 62%, respectively. In conclusion, the combination of thalidomide with VED appears to be highly effective in previously untreated patients with multiple myeloma, but it is associated with a high rate of thrombotic events, polyneuropathy, and neutropenic infections.

Low-dose thalidomide and donor lymphocyte infusion as adoptive immunotherapy after allogeneic stem cell transplantation in patients with multiple myeloma

To improve the antimyeloma effect of donor lymphocyte infusion (DLI) after allogeneic stem cell transplantation in multiple myeloma, we investigated in a phase 1/2 study the effect of low-dose thalidomide (100 mg) followed by DLI in 18 patients with progressive disease or residual disease and prior ineffective DLI after allografting. The overall response rate was 67%, including 22% complete remission. Major toxicity of thalidomide was weakness grade I/II (68%) and peripheral neuropathy grade I/II (28%). Only 2 patients experienced mild grade I acute graft versus host disease (aGvHD) of the skin, while no grades II to IV aGvHD was seen. De novo limited chronic GvHD (cGvHD) was seen in 2 patients (11%). The 2-year estimated overall and progression-free survival were 100% and 84%, respectively. Adoptive immunotherapy with low-dose thalidomide and DLI induces a strong antimyeloma effect with low incidence of graft versus host disease. (Blood. 2004;104:3361-3363)

Thalidomide for the treatment of multiple myeloma

Although thalidomide was withdrawn in the 1960s after its teratogenic property was recognized, it was subsequently found that this drug possesses immunomodulatory and anti-inflammatory effects. Recent studies have also demonstrated that thalidomide has antineoplastic activity via an antiangiogenic mechanism. Observations in the late 1990s that the microenvironment in the bone marrow plays a role in tumor progression in multiple myeloma provided an impetus to use thalidomide for the treatment of this disease. It is known that thalidomide monotherapy is effective in one-third of refractory cases, and in combination with glucocorticoids and/or antineoplastic drugs, thalidomide provides a response rate of more than 50%. Thus, thalidomide therapy is considered a standard approach for the treatment of relapsed and refractory myeloma. The exact mechanism of the antimyeloma effect of thalidomide is not yet clearly understood. Anti-angiogenic effects, direct activity in tumor cells such as the induction of apoptosis or G1 arrest of the cell cycle, the inhibition of growth factor production, the regulation of interactions between tumor and stromal cells, and the modulation of tumor immunity have been considered as possible mechanisms. In addition to its teratogenicity, the adverse effects of thalidomide have been general symptoms such as somnolence and headache, peripheral neuropathy, constipation, skin rash, and other symptoms. Although these adverse effects are generally reversible and mild, grade 3 and 4 toxicities such as peripheral neuropathy, deep venous thrombosis, neutropenia, and toxic dermal necrosis have occasionally been reported. The application of thalidomide therapy in patients with multiple myeloma is being broadened to include not only cases of refractory myeloma, but also previously untreated cases, as well as for maintenance therapy after hematopoietic stem cell transplantation and for the treatment of other hematological diseases. The safe use of this drug will depend on the establishment of diagnostic and treatment guidelines. In addition, the establishment of a nation-wide regulation system is urgently needed in Japan.

New drugs for treatment of multiple myeloma

Multiple myeloma (MM) is a disease of plasma cells that has fatal consequences. New insights into the biology of MM have identified molecular mechanisms that hold promise as therapeutic targets. Laboratory and preclinical studies have shown that intracellular regulatory proteins and functional interactions between MM cells and the bone-marrow microenvironment have a pivotal role in the growth, survival, drug resistance, and malignant progression of MM cells. New agents associated with molecular targets have prompted clinical investigators to design new treatment strategies initially for advanced MM and later for newly diagnosed MM, with encouraging preliminary results. Here, we discuss the mechanisms of action of these new rational drugs and the preliminary clinical outcomes of a new treatment regimen for MM.

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

Salvage therapy of patients with advanced, relapsed and refractory multiple myeloma (MM) is often limited by poor marrow reserve and multi-organ impairment. In particular, renal failure occurs in up to 50% of such patients, and this further limits the use of conventional chemotherapy. Thalidomide, both alone and in combination with dexamethasone, has been demonstrated to be useful in patients with advanced MM, as responses could be achieved in 30-60% of the cases. From May 2000 to November 2003, 20 consecutive MM patients (15 males, five females, median age 66.5 yr) with stage III relapsed/refractory MM and renal failure, defined as serum creatinine >130 mmol/L, gave their informed consent to be enrolled in a clinical trial aimed at evaluating the efficacy and the toxic effects of thalidomide. Three patients were undergoing chronic haemodialysis during the time of entry in the study. Eight patients have been treated with thalidomide as a single agent, at a starting dose of 100 mg/d, that was to be increased to 400 mg/d in case of good tolerance. Twelve patients have been treated with thalidomide at the maximum dose of 200 mg/d plus dexamethasone 40 mg/d for four consecutive days every 4 wk. A >50% decrease in serum or urine M component was observed in nine patients (45%), seven of whom have been treated with thalidomide + dexamethasone and three with thalidomide alone. Six additional patients achieved a minor response (>25% paraprotein decrease); the total response rate was thus 75%. Median response duration was 7 months (range 2-24 months). Four patients were refractory to treatment. Recovery of a normal renal function was observed in 12 of 15 responsive patients, two additional patients, in chronic haemodialysis, showed a reduction of serum creatinine. Toxicity profile of thalidomide with or without dexamethasone was comparable with that observed in patients with a normal renal function. In conclusion, our data show that thalidomide can be safely administered in patients with advanced MM and renal failure.

Thalidomide

Despite its history as a human teratogen, thalidomide is emerging as a treatment for cancer and inflammatory diseases. Although the evolution of its clinical application could not have been predicted from the tragedy associated with its misuse in the past, its history serves as a lesson in drug development that underscores the need to understand the molecular pharmacology of a compound's activity, including associated toxicities. Here, we summarise the applications for thalidomide with an emphasis on clinical trials published over the past 10 years, and consider our knowledge of the molecular pharmacology of the drug in the context of clinical trial data, attempting to provide a mechanism-guided understanding of its activity.

Phase I study to determine the safety, tolerability and immunostimulatory activity of thalidomide analogue CC-5013 in patients with metastatic malignant melanoma and other advanced cancers

We assessed the safety, tolerability and efficacy of the immunomodulatory drug, CC-5013 (REVIMID™), in the treatment of patients with metastatic malignant melanoma and other advanced cancers. A total of 20 heavily pretreated patients received a dose-escalating regimen of oral CC-5013. Maximal tolerated dose, toxicity and clinical responses were evaluated and analysis of peripheral T-cell surface markers and serum for cytokines and proangiogenic factors were performed. CC-5013 was well tolerated. In all, 87% of adverse effects were classified as grade 1 or grade 2 according to Common Toxicity Criteria and there were no serious adverse events attributable to CC-5013 treatment. Six patients failed to complete the study, three because of disease progression, two withdrew consent and one was entered inappropriately and withdrawn from the study. The remaining 14 patients completed treatment without dose reduction, with one patient achieving partial remission. Evidence of T-cell activation was indicated by significantly increased serum levels of sIL-2 receptor, granulocyte–macrophage colony-stimulating factor, interleukin-12 (IL-12), tumour necrosis factor-α and IL-8 in nine patients from whom serum was available. However, levels of proangiogenic factors vascular endothelial growth factor and basic foetal growth factor were not consistently affected. This study demonstrates the safety, tolerability and suggests the clinical activity of CC-5013 in the treatment of refractory malignant melanoma. Furthermore, this is the first report demonstrating T-cell stimulatory activity of this class of compound in patients with advanced cancer.

Bypass of tumor drug resistance by antivascular therapy

Multidrug resistance (MDR) presents a major obstacle for the successful chemotherapy of cancer. Its emergence during chemotherapy is attributed to a selective process, which gives a growth advantage to MDR cells within the genetically unstable neoplastic cell population. The pleiotropic nature of clinical MDR poses a great difficulty for the development of treatment strategies that aim at blocking MDR at the tumor cell level. Targeting treatment to the nonmalignant vascular network-the lifeline of the tumor-is a promising alternative for the treatment of drug-resistant tumors. The present study demonstrates that MDR in cancer can be successfully circumvented by photodynamic therapy (PDT) using an antivascular treatment protocol. We show that, although P-glycoprotein-expressing human HT29/MDR colon carcinoma cells in culture are resistant to PDT with Pd-bacteriopheophorbide (TOOKAD), the same treatment induces tumor necrosis with equal efficacy (88% vs 82%) in HT29/MDR-derived xenografts and their wild type counterparts, respectively. These results are ascribed to the rapid antivascular effects of the treatment, supporting the hypothesis that MDR tumors can be successfully eradicated by indirect approaches that bypass their inherent drug resistance. We suggest that with progress in ongoing clinical trials, TOOKAD-PDT may offer a novel option for local treatment of MDR tumors.

Thalidomide-Induced Severe Neutropenia during Treatment of Multiple Myeloma

Recent reports have shown that thalidomide has antiangiogenic activity and is effective for the treatment of refractory multiple myeloma. Unlike other antineoplastic drugs, thalidomide is reported to rarely cause severe hematologic toxicity. In Keio University Hospital, 44 patients with refractory multiple myeloma, including 18 who had relapsed after hematopoietic stem cell transplantation, were treated with this drug as a single agent. Severe grade 3 or 4 neutropenia during thalidomide treatment was observed in 10 patients. This phenomenon was not noted in previous reports. Neutropenia usually occurred in the first or second week of treatment. Concomitant progression of thrombocytopenia occurred in 5 cases, and bone marrow hypoplasia without a significant increase in myeloma cell numbers was also observed in 5 cases. Neutropenia was not correlated with anti-tumor response or the plasma concentration of thalidomide but was more frequently observed in patients with a low neutrophil and platelet count, anemia, or a high plasma cell percentage in the bone marrow before thalidomide treatment. Thus, this drug should be used carefully for patients with pretreatment cytopenia or a high tumor burden in the bone marrow.

The effects of selective cytokine inhibitory drugs (CC-10004 and CC-1088) on VEGF and IL-6 expression and apoptosis in myeloma and endothelial cell co-cultures

Myeloma cells and human umbilical vein endothelial cells (HUVECs) were co-cultured to model in vitro the interactions between myeloma and endothelium, and treated with thalidomide and two selective cytokine inhibitory drugs (SelCIDs, phosphodiesterase-4 inhibitors). Flow cytometry and enzyme-linked immunosorbent assay were used to assess production of two key cytokines--vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6)--and apoptosis in co-cultured HUVECs and myeloma cells. VEGF was produced by both myeloma cells and HUVECs, while IL-6 was almost exclusively produced by endothelial cells. In co-culture, there was significant up-regulation of VEGF and IL-6 production compared with the sum of separate myeloma and endothelial cell cultures. SelCIDs markedly inhibited production of both cytokines in co-cultures, with CC-10004 being more potent than CC-1088. In addition, SelCIDs induced myeloma cell apoptosis. Apoptosis in co-cultured myeloma cells was significantly lower than in those cultured separately, suggesting that co-culture partially protected myeloma cells from drug-induced apoptosis. This protective effect was probably due to IL-6 produced by endothelial cells in co-culture as addition of anti-IL-6 neutralizing antibody, but not anti-VEGF antibody, abrogated it. In conclusion, SelCIDs can exert their anti-myeloma activity through two mechanisms, i.e. inhibition of VEGF and IL-6 production by interacting myeloma and endothelium and induction of myeloma cell apoptosis.

Angiogenesis in human cancer: implications in cancer therapy

Angiogenesis represents an essential step in tumor proliferation, expansion, and metastasis. Tumor cells may express both proangiogenic and/or antiangiogenic factors. Under normal circumstances, angiogenesis is controlled through the equilibrium of these factors. This balance is disrupted in malignancy, resulting in promotion of angiogenesis. Among angiogenic molecules, VEGF appears to have a central role in the angiogenic process: it is the target of many proangiogenic factors, but it also regulates molecules that are implicated in endothelial proliferation. It has been suggested that VEGF may be a proximate angiogenic factor through which others act. The degree of angiogenesis and the expression of angiogenic factors have been associated with prognosis in several human neoplasms. In addition, angiogenesis offers a theoretically selective target for anticancer therapy, since it is only required for wound healing, endometrial proliferation, and pregnancy in healthy individuals. Antiangiogenic cancer treatment is still largely experimental and its clinical potential is currently being studied in clinical trials. Thalidomide, a drug with antiangiogenic properties, has shown significant efficacy in patients with relapsed or refractory multiple myeloma. In addition, an anti-VEGF monoclonal antibody prolonged survival in patients with advanced colorectal and renal cell carcinoma. Although these results are encouraging, selection of patients is essential in order to target populations most likely to benefit from antiangiogenic therapy.

Thalidomide in relapsed/refractory multiple myeloma: pivotal trials conducted outside the United States

Recently completed phase II trials and retrospective analyses conducted outside the United States, primarily in Europe and Australia, have confirmed results of landmark US trials that established the efficacy of thalidomide in multiple myeloma. These trials evaluated thalidomide alone or in combination in patients with heavily pretreated relapsed/ refractory multiple myeloma. Single-agent thalidomide induced objective responses in approximately one third of patients and prolonged survival by approximately 1 year. These trials also indicated a possible dose-response relationship of thalidomide and identified several poor prognostic factors, including advanced age, high lactose dehydrogenase level, low platelet count, and low hemoglobin level. The combination of thalidomide with dexamethasone increased overall response by approximately 20% and reduced the time to response compared with thalidomide alone. In addition, lower doses of thalidomide used in the combination may increase patient tolerability. Finally, thalidomide in combination with chemotherapy yields response rates of approximately 60%, with median survival times of approximately 18 months. Randomized trials are needed to confirm these results and further explore the role of thalidomide in these treatment settings.

Thalidomide in newly diagnosed multiple myeloma and overview of experience in smoldering/indolent disease

Based on the activity of single-agent thalidomide demonstrated in relapsed or refractory multiple myeloma, investigators have evaluated the role of this agent in the treatment of earlier stage disease. Two key phase II trials of thalidomide plus dexamethasone in patients with previously untreated symptomatic multiple myeloma have yielded overall response rates of 64% to 73%. Comparable response rates, reduced toxicity, and increased patient convenience with oral administration suggest it may offer an alternative to standard infusional chemotherapies, such as vincristine/doxorubicin/dexamethasone (VAD), before stem cell mobilization and high-dose chemotherapy in patients with active disease; further study is warranted. Two key phase II trials of single-agent thalidomide in patients with smoldering/indolent (asymptomatic) disease have yielded overall response rates of approximately 35%, and further study of thalidomide in this setting is also indicated. The primary toxicities of thalidomide-based therapy are neuropathy, sedation/fatigue, constipation, and rash. Studies of thalidomide in combination with dexamethasone suggest toxicities of both agents may be increased due to the synergy of these agents. Phase III trials of thalidomide in newly diagnosed symptomatic multiple myeloma or smoldering/indolent disease are ongoing.

Thalidomide and CC-5013 in multiple myeloma: the University of Arkansas experience

Based on the activity of single-agent thalidomide in relapsed/refractory multiple myeloma in a landmark phase II study of 169 patients conducted at the University of Arkansas for Medical Sciences (UAMS), UAMS initiated several trials of thalidomide and the more potent thalidomide analog CC-5013. In an ongoing trial evaluating thalidomide plus the proteasome inhibitor bortezomib and dexamethasone in patients with relapsed/refractory disease following stem cell transplantation, approximately 50% of patients have experienced a paraprotein reduction of 50% or greater. In patients without cytogenetic abnormalities, the estimated 12-month event-free and overall survival rates are 69% and 100%, respectively. In a second ongoing trial building on the UAMS Total Therapy I regimen, newly diagnosed patients are randomized to thalidomide or no thalidomide pretransplantation followed by consolidation therapy with dexamethasone and multiagent chemotherapy post-transplantation (Total Therapy II). Although the Total Therapy II regimen appears to be superior to the original Total Therapy I regimen, assessment of the effect of thalidomide on Total Therapy II is pending accrual completion. Lastly, based on the increased potency and reduced toxicity profile of CC-5013 compared with thalidomide, a study of CC-5013 in patients with relapsed/refractory disease following transplantation was initiated. Patients are randomized to CC-5013 25 mg daily for 20 days versus CC-5013 50 mg every other day for 10 days. Preliminary results indicate the superiority of the 25-mg arm, with 40% of patients randomized to that arm experiencing a paraprotein reduction of 50% or greater. These preliminary results corroborate the role for thalidomide and CC-5013 in relapsed/refractory and newly diagnosed multiple myeloma based on the UAMS phase II study as well as several other studies of these agents outside of UAMS.

Therapy strategies for multiple myeloma: current status

Multiple myeloma (MM) is characterized by infiltration of bone marrow with a clone of neoplastic plasma cells. Impaired hematopoiesis and reduced production of functional immunoglobulins, as well as the induction of pathognomonic osteolytic lesions primarily contribute to the morbidity of patients with MM. Conventional chemotherapy is the treatment of choice for older patients, whereas those under 60 years benefit significantly from high-dose therapy followed by stem-cell rescue. The use of tandem transplantation, developed to further escalate the conditioning dose, has achieved additional improvement in survival. Interferon-alpha and glucocorticoids are effective as maintenance measures in MM but remain controversial because of their associated high costs and considerable toxicity. The resurrection of an old drug, thalidomide, for the therapy of MM and the development of potent immunomodulatory derivatives are highly promising new treatments that target MM cell-host interactions and the bone-marrow microenvironment, as well as the myeloma cell itself. The importance of the use of bisphosphonates for the prevention or amelioration of skeletal complications and hypercalcemia is well established. New generations of bisphosphonates show potent antitumor activity, again emphasising the importance of targeting the microenvironment of the plasma-cell clone.

Intermediate dose thalidomide (200 mg daily) has comparable efficacy and less toxicity than higher doses in relapsed multiple myeloma

Thalidomide at doses >200 mg has 100% grade 1-2 and 25% grade 3-4 toxicities requiring discontinuation. We report a retrospective study of relapsed myeloma patients treated with thalidomide 200 mg with no dose escalation. Thirty patients were identified; 43% of patients responded with paraprotein decline >75% -- 2 (6%), 50-75% -- 7 (23%), 25-50% -- 4 (14%) and 2 (6%) were stable. All five patients with 13q deletion responded. Only 54% reported grade 1-2 toxicities (none reporting > grade 2) with 5 (17%) discontinuing treatment due to toxicity. Thalidomide 200 mg daily with no dose escalation appears as effective and better tolerated than escalated doses for relapsed myeloma patients.

Thalidomide: a new anticancer drug?

Experimental studies have demonstrated that thalidomide (Thal), a drug developed as a sedative, has antitumoural properties. The possible antitumour mechanisms of action involve: inhibition of angiogenesis, cytokine-mediated pathways, modulation of adhesion molecules, inhibition of cyclooxygenase-2 and stimulation of immuno response. Therefore, Thal is under clinical evaluation in oncology. This paper provides an overview of the data currently available in literature regarding, in terms of activity and toxicity, the use of Thal in cancer patients. Multiple myeloma is so far the most responsive malignancy. A moderate activity has been documented in certain solid tumours: glioblastoma multiforme, renal cell carcinoma and malignant melanoma. Tolerability is generally satisfactory with peripheral neuropathy being the most relevant dose-dependent toxicity. The more frequent, but moderate side effects are: somnolence, constipation, dizziness and fatigue. More studies are needed to properly evaluate the anticancer activity of Thal alone or in combination with other anticancer treatments. Preliminary studies suggest promising results of Thal in combinations with corticosteroids and cytotoxic drugs as front-line therapy of multiple myeloma. Regarding therapy of solid tumours in the adult, combination with chemotherapy, radiation therapy and molecular-targeting compounds are under investigation.

Treatment of multiple myeloma

Conventional chemotherapies are no longer the only treatment in multiple myelomatosis. High-dose chemotherapy and autologous transplantation are not curative but do increase relapse-free survival time in young patients. Thalidomide is efficacious in refractory and relapsing myeloma and its evaluation is going on. Curative and preventive treatments of skeletal events, infections and anemia improve quality of life. All together, these strategies imply therapeutic knowledge and choices but allow an about 5-year-long median survival time in modern studies. Treatment options for myeloma now include, not only conventional chemotherapy regimens, but also novel symptomatic drugs and strategies that increase survival and/or quality of life, although they fail to provide a cure. In parallel with this expansion of the treatment armamentarium, physicians must acquire the knowledge needed to select the best treatment for the individual patient. After reviewing the rationale, effectiveness, and safety of each of these treatments, we will discuss the indications that we believe are legitimate.

Bone marrow angiogenesis and progression in multiple myeloma: clinical significance and therapeutic approach

It is now well established that solid tumors depend on angiogenesis. Promoters and inhibitors of angiogenesis are in balance and antiangiogenic strategies aim at repressing the angiogenic process, thus retarding solid tumor progression. Recent data suggest the importance of angiogenesis in hematologic malignancies and several studies reveal an increased angiogenesis in active multiple myeloma. Angiogenesis seems to be a prominent feature of MM progression, and seems to be correlated with the prognosis and the resistance of MM to chemotherapy. Numerous cell populations and cytokines are involved in angiogenesis in multiple myeloma and antiangiogenic therapy with thalidomide is effective in patients with refractory or relapsed disease. The combination of thalidomide and of other immunomodulatory agents with other therapeutic regimens could lead to more effective management of patients with multiple myeloma.

Thalidomide dosing in patients with relapsed or refractory multiple myeloma

OBJECTIVE

To evaluate the literature regarding the dosing of thalidomide in multiple myeloma.

DATA SOURCES

A MEDLINE search (1990-February 2003) using the search terms thalidomide and multiple myeloma was performed to identify clinical trials and abstracts. Identified literature was then cross-referenced for further pertinent data.

DATA SYNTHESIS

Patients with relapsed or refractory multiple myeloma have few therapeutic options. Thalidomide is a promising agent, although many dose-related issues are still in question. Starting doses studied ranged from 50 to 200 mg/d, usually given at bedtime. Gradual dose escalation up to 800 mg/d has been studied, with some evidence of improved outcome with doses of 400-600 mg/d, while thalidomide appears to be best tolerated at doses </=400 mg/d.

CONCLUSIONS

A reasonable approach for use of thalidomide in multiple myeloma is to initiate therapy at 50-100 mg nightly and escalate every 2 weeks in 50- to 100-mg increments as tolerated. Efforts should be made to titrate the dose to 400-600 mg/d, especially in patients with poor prognostic features. Efficacy should be assessed at approximately 8 weeks and the dose maintained if desired response is achieved.

Angiogenesis in Waldenstrom's macroglobulinemia

Angiogenesis has been associated with disease progression and poor prognosis in several hematologic malignancies including multiple myeloma. In this article, we summarize the rationale for studying angiogenesis in plasma cell disorders including Waldenstrom's macroglobulinemia (WM). We also discuss the results of a study of angiogenesis in WM conducted at the Mayo Clinic. Our study shows that only 30% of patients with WM had increased (intermediate- or high-grade) angiogenesis. A weak correlation was found between mean microvessel density (MVD) and marrow infiltration. Unlike multiple myeloma, MVD and angiogenesis grade were not predictive factors for survival. Although these findings suggest that angiogenesis may not be a major factor in WM, it does not exclude a paracrine role for angiogenic cytokines or the study of antiangiogenic agents in this disease.

Novel therapies in multiple myeloma

The discovery of the activity of thalidomide in myeloma in the late 1990s transformed the therapy of myeloma dramatically. Apart from providing a useful treatment option for patients with myeloma, it has spurred clinical investigation of several other nonchemotherapeutic agents for this disease. These active, promising agents include CC-5013 (a thalidomide analog) and bortezomib (a proteasome inhibitor), as well as other agents, such as arsenic trioxide, ENMD 0995 and 2-methoxyestradiol. Preliminary data show that a number of these agents are active in treating disease that has relapsed after conventional chemotherapy as well as after high-dose therapy and transplantation, and some agents are active even after other novel agents have failed. The only novel drug that is commercially available currently is thalidomide, which has a therapeutically relevant benefit at all stages of the disease. A therapeutic trial of thalidomide is essential for all patients with myeloma. There are in vitro and in vivo data showing synergy between some of the novel agents. Although these novel drugs are typically used for treating disease that is refractory to or has relapsed after cytotoxic therapy, it is likely that they will start being used as part of frontline therapy, either by themselves or in combination with chemotherapy.