Thalidomide as an anti-TNF-alpha inhibitor: implications for clinical use

Thalidomide inhibits UVB-induced mouse keratinocyte apoptosis by both TNF-α-dependent and TNF-α-independent pathways

BACKGROUND

Thalidomide is an anti-inflammatory pharmacologic agent that has been utilized as a therapy for a number of dermatologic diseases. Its anti-inflammatory properties have been attributed to its ability to antagonize tumor necrosis factor-alfa (TNF-alpha) production by monocytes. However, its mechanism of action in the skin is not known.

PURPOSE

To test our hypothesis that thalidomide may antagonize TNF-alpha production in the skin, we used a mouse model for acute ultraviolet-B (UVB) exposure, a known stimulus for inducing this cytokine.

RESULTS

A single bolus dose of thalidomide (either 100 or 400 mg/kg) given immediately before UVB exposure (40-120 mJ/cm2) inhibited, in a dose-dependent manner, sunburn cell formation (i.e. keratinocyte (KC) apoptosis as defined by histologic appearance and confirmed by terminal transferase mediated biotinylated dUTP nick end labelling staining) in mouse skin biopsy specimens. However, this agent did not affect the formation of cyclobutane pyrimidine dimers, a measure of UVB-induced DNA damage, which is an early event associated with apoptosis. RNase protection assays confirmed that high (400 mg/kg), but not low (100 mg/kg), doses of thalidomide inhibited the UVB-induced increase in steady-state TNF-alpha mRNA. Additionally, our in vitro data using neonatal mouse KCs showed that thalidomide prevented UVB-induced cell death (JAM assay). The antiapoptotic effects of thalidomide can be reversed by the addition of exogenous recombinant mouse TNF-alpha and hence reconstituting UVB-induced programmed cell death. The inhibition of sunburn cell formation by low-dose thalidomide in the absence of TNF-alpha inhibition suggests that other, unidentified mechanisms of apoptosis inhibition are active.

CONCLUSIONS

These data suggest that the anti-inflammatory effects of thalidomide can affect UVB injury, and may, in part, explain its action in photosensitivity diseases such as cutaneous lupus erythematosus.

Dermatologic and nondermatologic uses of thalidomide

OBJECTIVE

To review published data on thalidomide, with emphasis on current knowledge about mechanism of action, new and/or potential dermatologic and nondermatologic therapeutic applications, well-known and emerging adverse effects, and current indications for its safe use.

DATA SOURCES

Review articles, in vitro research studies, references from retrieved articles, case reports, and clinical trials were identified from a computerized literature search using MEDLINE and OVID (1966-January 2003) and on the Cochrane Clinical Trials Register (January 2003). Information available from meetings' abstract books, Internet, or pharmaceutical companies was also considered.

STUDY SELECTION AND DATA EXTRACTION

All articles identified as relevant, including those from non-English literature, were considered in an attempt to provide to the reader both the theoretical basis and practical guidelines for thalidomide pharmacotherapy.

DATA SYNTHESIS

Thalidomide has hypnosedative, antiangiogenic, antiinflammatory, and immunomodulatory properties. Moreover, it has been shown to selectively inhibit the production of tumor necrosis factor-alpha and reduce the expression of various integrin receptors on the membrane of leukocytes and other cell types in a dose-dependent fashion. Controlled trials demonstrated the efficacy of thalidomide in a number of diseases, including erythema nodosum leprosum, lupus erythematosus, aphthosis, graft-versus-host disease, prurigo nodularis, and actinic prurigo. Single case reports or studies in small series have also suggested a possible role for thalidomide in numerous other dermatologic and nondermatologic disorders. Possibly severe and sometimes irreversible risks related to the clinical use of thalidomide include teratogenicity and neurotoxicity.

CONCLUSIONS

Although teratogenicity and neurotoxicity are significant adverse effects requiring cautious use, thalidomide is an effective therapeutic modality in a variety of difficult-to-treat disorders and, providing careful selection of patients, should offer an acceptable risk-to-benefit ratio.

Rethinking nutritional support for persons with cancer cachexia

Cancer cachexia is a poorly understood syndrome of anorexia, weight loss, and muscle wasting that negatively impacts quality of life and survival in cancer patients. Research has clearly implicated pro-inflammatory cytokines in the biology of cancer cachexia. More recent research implicates products of arachidonic acid and suggests that cachexia may be a chronic inflammatory condition rather than a nutritional aberration. To date, nutritional support to slow weight loss has focused primarily on increasing calorie intake. Alternatively, many foods contain factors that can modulate the synthesis or activity of pro-inflammatory mediators, especially the synthesis of prostaglandin E2 from arachidonic acid. These factors and foods are sometimes called nutraceuticals, and research is needed to evaluate their efficacy in combating cancer cachexia.

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.

Management of spondyloarthropathy: new pharmacological treatment options

Spondyloarthropathies (SpA) are a group of inflammatory arthritides classified according to common features of peripheral and spinal arthritis. The conventional anti-inflammatory and disease-modifying or slow-acting anti-rheumatic drugs do appear to be efficacious in treatment of the peripheral arthritis in a comparable fashion to seropositive rheumatoid arthritis, however, their efficacy in axial disease is unproven. This review examines new pharmacological developments in the treatment of SpA including the specific features of sacroiliitis, enthesitis and spondylitis in addition to the peripheral manifestations. The main points that are discussed are new cyclo-oxygenase (COX)-2 specific anti-inflammatories, biological therapies, such as anti-TNF compounds, and novel uses of well-known agents.

Thalidomide for erythema nodosum leprosum and other applications

Thalidomide, administered as a sedative and antiemetic decades ago, was considered responsible for numerous devastating cases of birth defects and consequently was banned from markets worldwide. However, the drug remarkably has resurfaced with promise of immunomodulatory benefit in a wide array of immunologic disorders for which available treatments were limited. It is approved by the Food and Drug Administration for erythema nodosum leprosum (ENL). Although the relative paucity of leprosy and ENL worldwide may perceivably limit interest in and knowledge about thalidomide, increasing numbers of new and potential uses expand its applicability widely beyond ENL. Thalidomide, an inhibitor of tumor necrosis factor a, is the best known agent for short-term treatment of ENL skin manifestations, as well as postremission maintenance therapy to prevent recurrence. For this indication, it is effective as monotherapy and as part of combination therapy with corticosteroids. Studies of thalidomide in chronic graft-versus-host disease showed benefit in children and adults as treatment, but not as prophylaxis. The agent has been administered successfully for treatment of cachexia related to cancer, tuberculosis, and human immunodeficiency virus infection, although evidence of efficacy is inconclusive. Thalidomide monotherapy effectively induced objective response in trials in patients with both newly diagnosed and advanced or refractory multiple myeloma. Combination therapy with thalidomide and corticosteroids was also effective in these patients, as well as in treatment of aphthous and genital ulcers. Limited evidence supports the drug's benefit in treatment of Kaposi's sarcoma. Other thalidomide applications include Crohn's disease, rheumatoid arthritis, and multiple sclerosis. Somnolence, constipation, and rash were the most frequently cited adverse effects in studies, but thalidomide-induced neuropathy and idiopathic thromboembolism were critical causes for drug discontinuation. Thalidomide is still contraindicated in pregnant women, women of childbearing age, and sexually active men not using contraception. Clinicians should be conversant with thalidomide in ENL (its primary application) in the natural course of leprosy, as well as in the agent's other applications.

TNFalpha inhibition in MRL/lpr mice ameliorates pulmonary but not renal disease

TNFalpha inhibition has a clearly beneficial effect in a number of arthritides and in Crohn's disease. The exact mechanism of action is uncertain with studies showing inhibition of chemokines, inhibition of adhesion molecule expression, and improved T-cell function. Unlike most therapeutic interventions for autoimmune disease, TNFalpha inhibition appears to act on specific pathologic processes. It is not known how wide-spread these TNFalpha-mediated pathologic processes are. Efforts to expand the use of TNFalpha inhibition have had notable successes but have been disappointing in other disorders. We hypothesized that TNFalpha-mediated pathologic processes might play a significant role in the end-organ effects seen in SLE. We modeled SLE by using MRL/lpr mice and treated with two types of TNFalpha inhibitor. Pulmonary disease was significantly improved in the treated groups compared to controls. In contrast, renal disease was unaffected suggesting that in lupus, where multiple organs are affected, different pathologic processes may be mediating the end-organ damage. This has important implications for designing therapeutics for SLE.

Thalidomide in dermatology

Thalidomide is an effective agent to treat over 25 seemingly unrelated dermatological conditions that have an inflammatory or autoimmune basis. The main side-effects of teratogenesis and peripheral neuropathy limit its use. Currently, in Australia no assurance is given as to the quality, safety and efficacy of thalidomide. The use of thalidomide for toxic epidermal necrolysis can lead to an increase in mortality, and its use as a prophylactic agent for the prevention of chronic graft-versus-host disease following bone marrow transplantation has raised more speculations as to the safety of this notorious drug. A review of the therapeutic indications for thalidomide in dermatology as well as the mechanisms of action and side-effects of this drug are presented. The current suggested guidelines for its use in clinical practice in Australia are discussed.

Thalidomide in cancer treatment: a potential role in the elderly?

There is increased interest in the treatment of cancer with thalidomide because of its antiangiogenic, immunomodulating and sedative effects. In animal models, the antitumour activity of thalidomide is dependent on the species, route of administration and coadministration of other drugs. For example, thalidomide has shown antitumour effects as a single agent in rabbits, but not in mice. In addition, the antitumour effects of the conventional cytotoxic drug cyclophosphamide and the tumour necrosis factor inducer 5,6-dimethylxanthenone-4-acetic acid (DMXAA) were found to be potentiated by thalidomide in mice bearing colon 38 adenocarcinoma tumours. Further studies have revealed that thalidomide upregulates intratumoral production of tumour necrosis factor-alpha 10-fold over that induced by DMXAA alone. Coadministration of thalidomide also significantly reduced the plasma clearance of DMXAA and cyclophosphamide. All these effects of thalidomide may contribute to the enhanced antitumour activity. Recent clinical trials of thalidomide have indicated that it has minimal anticancer activity for most patients with solid tumours when used as a single agent, although it was well tolerated. However, improved responses have been reported in patients with multiple myeloma. Palliative effects of thalidomide on cancer-related symptoms have also been observed, especially for geriatric patients with prostate cancer. Thalidomide also eliminates the dose-limiting gastrointestinal toxic effects of irinotecan. There is preliminary evidence indicating that the clearance of thalidomide may be reduced in the elderly. The exact role of thalidomide in the treatment of cancer and cancer cachexia in the elderly remains to be elucidated. However, it may have some value as part of a multimodality anticancer therapy, rather than as a single agent.

Thalidomide suppresses NF-kappa B activation induced by TNF and H2O2, but not that activated by ceramide, lipopolysaccharides, or phorbol ester

Thalidomide ([+]-alpha-phthalimidoglutarimide), a psychoactive drug that readily crosses the blood-brain barrier, has been shown to exhibit anti-inflammatory, antiangiogenic, and immunosuppressive properties through a mechanism that is not fully established. Due to the central role of NF-kappaB in these responses, we postulated that thalidomide mediates its effects through suppression of NF-kappaB activation. We investigated the effects of thalidomide on NF-kappaB activation induced by various inflammatory agents in Jurkat cells. The treatment of these cells with thalidomide suppressed TNF-induced NF-kappaB activation, with optimum effect occurring at 50 microg/ml thalidomide. These effects were not restricted to T cells, as other hematopoietic and epithelial cell types were also inhibited. Thalidomide suppressed H(2)O(2)-induced NF-kappaB activation but had no effect on NF-kappaB activation induced by PMA, LPS, okadaic acid, or ceramide, suggesting selectivity in suppression of NF-kappaB. The suppression of TNF-induced NF-kappaB activation by thalidomide correlated with partial inhibition of TNF-induced degradation of an inhibitory subunit of NF-kappaB (IkappaBalpha), abrogation of IkappaBalpha kinase activation, and inhibition of NF-kappaB-dependent reporter gene expression. Thalidomide abolished the NF-kappaB-dependent reporter gene expression activated by overexpression of TNFR1, TNFR-associated factor-2, and NF-kappaB-inducing kinase, but not that activated by the p65 subunit of NF-kappaB. Overall, our results clearly demonstrate that thalidomide suppresses NF-kappaB activation specifically induced by TNF and H(2)O(2) and that this may contribute to its role in suppression of proliferation, inflammation, angiogenesis, and the immune system.

Thalidomide in myelodysplastic syndromes

The myelodysplastic syndromes are a heterogeneous group of clonal diseases of haemopoiesis, which are a challenge for both biologists and clinicians. In this paper the current classification and the recent advances in the understanding the disease mechanisms are reviewed. The recent therapeutic advances are also indicated, such as intensive and low-dose chemotherapy, new drugs, erythropoietin and colony-stimulating factors. However, the work has been focused on thalidomide, its therapeutic potential, its modes of actions, side effects, indications and future applications.

Thalidomide in Behçet's disease

Behçet's disease is a chronic relapsing multisystem disease of unknown aetiology. It has a relapsing cyclical course, and is characterized by the triad of aphthous stomatitis, genital ulcerations and uveitis. There is familial and geographical clustering of cases, especially around the Mediterranean, the Middle East and East Asia. The condition is uncommon, but lesions sometimes are recalcitrant and can be debilitating to the affected individual. The treatment of Behçet's currently involves the use of steroids, immunomodulaters and immunosuppressives. Thalidomide has been used in cases of Behçet's disease with some success. This review will discuss Behçet's disease and the current information we have about using thalidomide for its treatment.

Thalidomide: new indications?

Thalidomide, which was developed as a nonbarbiturate sedative agent, was taken off the market in 1961 after it was linked to a spate of major birth defects. Gradually, thalidomide was reintroduced for the treatment of a few skin diseases including leprous erythema nodosum, severe mucosal ulcers (e.g., associated with HIV infection or Behçet's disease), lymphocytic skin infiltrations, cutaneous lupus erythematosus, and chronic graft-versus-host disease. Recent reports of original pharmacological properties including modulation of cytokine production (mainly reduced TNF-alpha production) and inhibition of angiogenesis have led to the suggestion that thalidomide may be useful in some inflammatory and neoplastic conditions. Several open-label studies and case reports have described the effects of thalidomide in Crohn's disease, rheumatoid arthritis, ankylosing spondylarthritis, systemic sclerosis, and a few other systemic disorders. In these indications, minor but dose-limiting side effects were apparently common. Thalidomide analogs with better acceptability profiles are under evaluation. The anti-angiogenic effects of thalidomide may make this compound valuable as single-drug therapy or as an adjunct to chemotherapy in patients with cancer, particularly those with metastases or multiple myeloma. This possibility requires further evaluation.

Thalidomide produces transfusion independence in long-standing refractory anemias of patients with myelodysplastic syndromes

Thalidomide was administered to 83 patients with myelodysplastic syndrome (MDS), starting at 100 mg by mouth daily and increasing to 400 mg as tolerated. Thirty-two patients stopped therapy before 12 weeks (minimum period for response evaluation), and 51 completed 12 weeks of therapy. International Working Group response criteria for MDS were used to evaluate responses. Intent-to-treat (ITT) analysis classified all off-study patients as nonresponders. Off-study patients belonged to a higher risk category (P =.002) and had a higher percentage of blasts in their pretherapy bone marrow than patients who completed 12 weeks of therapy (P =.003). No cytogenetic or complete responses were seen, but 16 patients showed hematologic improvement, with 10 previously transfusion-dependent patients becoming transfusion independent. Responders had lower pretherapy blasts (P =.016), a lower duration of pretherapy platelet transfusions (P =.013), and higher pretherapy platelets (P =.003). Among responders, 9 had refractory anemia (RA); 5 had RA with ringed sideroblasts; and 2 had RA with excess blasts. By ITT analysis, 19% of patients (16 of 83) responded, and when only evaluable patients were analyzed, 31% (16 of 51) responded. It was concluded that thalidomide, as a single agent, is effective in improving cytopenias of some MDS patients, especially those who present without excess blasts. (Blood. 2001;98:958-965)

Safety and efficacy of thalidomide in patients with myelofibrosis with myeloid metaplasia

We administered the anti-angiogenic drug thalidomide to 21 patients (12 men) with myelofibrosis with myeloid metaplasia (MMM), who were not responsive to standard treatment. Patients received thalidomide at an escalating dose from 100 to 400 mg/d. Administration of the drug was discontinued before the planned 6 months of treatment in 19 patients (90.5%), mainly because of somnolence and/or fatigue, neurological symptoms or neutropenia. Of the 13 evaluable patients (who received more than 30 d of therapy), anaemia improved in three out of seven (43%) who were treated because of anaemia; thrombocytopenia improved in two out of three (66.6%) who were treated because of thrombocytopenia; splenomegaly was reduced in four (30.8%). Undesired increases in white blood cell and platelet counts were observed in three (23.1%) and five (38.5%) patients respectively. A severity score, indexed on haematological and clinical parameters, improved in two patients (15.4%), but worsened in five (38.5%). In conclusion, standard-dose thalidomide in MMM patients is burdened with a high rate of side-effects, which prevent prolonged treatment. Because the drug is effective in improving anaemia and thrombocytopenia and in reducing splenomegaly, low-dose therapy warrants evaluation. The unexpected observation of leucocytosis and thrombocytosis suggests biological studies and better criteria for selection of patients for treatment.

Efficacy of long-term treatment with thalidomide in children and young adults with Crohn disease: preliminary results

BACKGROUND

Several proinflammatory cytokines are involved in the pathogenesis of inflammatory bowel diseases. A significant role has been given to tumor necrosis factor alpha (TNF-alpha) as a guide proinflammatory cytokine. Thalidomide selectively reduces TNF-alpha production by inflammatory cells. The aim of the study was to assess the efficacy of thalidomide to induce and maintain remission in refractory Crohn disease.

METHODS

The decision to administer thalidomide was made on the basis of patient intolerance or resistance to conventional medical treatment or as the last medical resort before surgical intervention. Only 5 of 96 patients with inflammatory bowel disease satisfied these criteria. All five patients had Crohn disease (male: mean age, 17 years). Thalidomide was administered at night at a dose of 1.5-2 mg/kg/day. The Pediatric Crohn Disease Activity Index, modified Harvey-Bradshaw scores, and steroids reduction were used to assess clinical response.

RESULTS

Disease activity decreased consistently in four patients with a reduction of mean Pediatric Crohn Disease Activity Index from 36,9 to 2,5 and the mean Harvey-Bradshaw from 8.5 to 0.75 after 3 months of treatment. Steroid treatment (mean dose, 35 mg/day before treatment) was tapered and then discontinued, in four patients, within 1-3 months. Four patients are in remission after 19-24 months of treatment. The fifth patient discontinued thalidomide after 1 week because of distal paresthesia.

CONCLUSION

Thalidomide seems to be an effective and safe treatment in patients with refractory Crohn disease. This is the first report of long-term use of thalidomide in refractory Crohn disease in pediatric patients.

Plasma concentrations of soluble tumor necrosis factor receptor I and tumor necrosis factor during cardiopulmonary bypass

BACKGROUND

Tumor necrosis factor-alpha (TNF) has been implicated in the development of postoperative morbidity after cardiopulmonary bypass for myocardial revascularization. Despite their postulated roles as modulators of TNF bioavailability, soluble TNF receptors have not been characterized in patients undergoing this procedure and is the focus of this study.

METHODS

Soluble tumor necrosis factor receptor I (sTNFRI) and TNF were measured by immunoassay in plasma samples collected from 36 patients at events before, during, and after cardiopulmonary bypass.

RESULTS

Plasma concentrations of sTNFRI averaged 1.39 ng/mL at the start of the operation. Preoperative sTNFRI concentrations were found to significantly correlate with a preoperative morbidity assessment score, age, duration of bypass, duration of supplemental oxygen, and length of hospital stay. Plasma sTNFRI increased in all of the patients during the procedure. Plasma concentrations of sTNFRI and TNF did not correlate at any time.

CONCLUSIONS

Preoperative measurement of sTNFRI could potentially serve as a reliable indicator for prophylactic treatment with an anti-TNF therapy. Such a therapeutic approach might help attenuate inflammatory processes thought to underlie postoperative morbidity associated with cardiopulmonary bypass.

Anti-TNF therapies in rheumatoid arthritis, Crohn's disease, sepsis, and myelodysplastic syndromes

An attempt has been made in this article to summarize the state-of-the-art clinical experience with the use of anti-TNF therapies in four diseased states with special emphasis on myelodysplastic syndromes. Given the central role of TNF-alpha in initiating and perpetuating the chronic damage produced in the diseased organs by controlling a cascade of pro-inflammatory cytokines, as well as its acute role in sepsis, theoretically speaking, neutralization of this peptide was a natural therapeutic choice. Results of the initial clinical trials appear encouraging and sometimes dramatic in their efficacy. The mechanism of response however, is interesting in that even when TNF-alpha is directly targeted by a monoclonal antibody, the resulting benefits can frequently not be attributed to TNF suppression alone. Rather, it appears that a more general effect on the T-lymphocytes is also contributing to the responses being seen. This raises the new possibility of combining anti-cytokine and anti-T-cell strategies to treat at least the more chronic diseases such as Crohn's disease and myelodysplastic syndromes. Continued clinical trials testing these strategies are clearly warranted.

Phase II evaluation of thalidomide in patients with metastatic breast cancer

PURPOSE

To determine the efficacy, safety, pharmacokinetics, and effect on serum angiogenic growth factors of two dose levels of thalidomide in patients with metastatic breast cancer.

PATIENTS AND METHODS

Twenty-eight patients with progressive metastatic breast cancer were randomized to receive either daily 200 mg of thalidomide or 800 mg to be escalated to 1,200 mg. Fourteen heavily pretreated patients were assigned to each dose level. Each cycle consisted of 8 weeks of treatment. Pharmacokinetics and growth factor serum levels were evaluated.

RESULTS

No patient had a true partial or complete response. On the 800-mg arm, 13 patients had progressive disease at or before 8 weeks of treatment and one refused to continue treatment. The dose was reduced because of somnolence to 600 mg for five patients and to 400 mg for two and was increased for one to 1,000 mg and for four to 1,200 mg. On the 200-mg arm, 12 patients had progressive disease at or before 8 weeks and two had stable disease at 8 weeks, of whom one was removed from study at week 11 because of grade 3 neuropathy and the other had progressive disease at week 16. Dose-limiting toxicities included somnolence and neuropathy. Adverse events that did not require dose or schedule modifications included constipation, fatigue, dry mouth, dizziness, nausea, anorexia, arrhythmia, headaches, skin rash, hypotension, and neutropenia. Evaluation of circulating angiogenic factors and pharmacokinetic studies failed to provide insight into the reason for the lack of efficacy.

CONCLUSION

Single-agent thalidomide has little or no activity in patients with heavily pretreated breast cancer. Further studies that include different patient populations and/or combinations with other agents might be performed at the lower dose levels.

Mechanism of action in thalidomide teratogenesis

In this commentary, we describe a model to explain the mechanism of the embryopathy of thalidomide. We propose that thalidomide affects the following pathway during development: insulin-like growth factor I (IGF-I) and fibroblast growth factor 2 (FGF-2) stimulation of the transcription of alphav and beta3 integrin subunit genes. The resulting alphavbeta3 integrin dimer stimulates angiogenesis in the developing limb bud, which promotes outgrowth of the bud. The promoters of the IGF-I and FGF-2 genes, the genes for their binding proteins and receptors, as well as the alphav and beta3 genes, lack typical TATA boxes, but instead contain multiple GC boxes (GGGCGG). Thalidomide, or a breakdown product of thalidomide, specifically binds to these GC promoter sites, decreasing transcription efficiency of the associated genes. A cumulative decrease interferes with normal angiogenesis, which results in truncation of the limb. Intercalation into G-rich promoter regions of DNA may explain why certain thalidomide analogs are not teratogenic while retaining their anti-tumor necrosis factor-alpha (TNF-alpha) activity, and suggests that we look elsewhere to explain the action of thalidomide on TNF-alpha. On the other hand, the anti-cancer action of thalidomide may be based on its antiangiogenic action, resulting from specific DNA intercalation. The tissue specificity of thalidomide and its effect against only certain neoplasias may be explained by the fact that various developing tissues and neoplasias depend on different angiogenesis or vasculogenesis pathways, only some of which are thalidomide-sensitive.

New therapies for heart failure: is thalidomide the answer?

The syndrome of advanced heart failure is associated with considerable morbidity and mortality. Ideas about the reasons for the progressive nature of the heart failure syndrome have changed over the years, with the initial view that progression was principally due to pump failure (the 'haemodynamic' hypothesis), giving way to more modern views, which implicate neuro-endocrine activation (including catecholamine excess, renin-angiotensin system activation, etc.). More recently, an excess of inflammatory cytokines has been found in advanced heart failure and implicated in the progression of the disease. Amongst the cytokines found, TNF-alpha seems to be particularly important. The principle therapeutic action of thalidomide appears to be reduction of TNF-alpha levels. We therefore suggest that there may be a role for thalidomide, or its derivatives, in the management of advanced heart failure.

Thalidomide: current and potential clinical applications

More than three decades after its withdrawal from the world marketplace, thalidomide is attracting growing interest because of its reported immunomodulatory and anti-inflammatory properties. Current evidence indicates that thalidomide reduces the activity of the inflammatory cytokine tumor necrosis factor (TNF)-alpha by accelerating the degradation of its messenger RNA. Thalidomide also inhibits angiogenesis. Recently, the drug was approved for sale in the United States for the treatment of erythema nodosum leprosum, an inflammatory complication of Hansen's disease. However, it has long been used successfully in several other dermatologic disorders, including aphthous stomatitis, Behçet's syndrome, chronic cutaneous systemic lupus erythematosus, and graft-versus-host disease, the apparent shared characteristic of which is immune dysregulation. Many recent studies have evaluated thalidomide in patients with human immunodeficiency virus (HIV) infection; the drug is efficacious against oral aphthous ulcers, HIV-associated wasting syndrome, HIV-related diarrhea, and Kaposi's sarcoma. To prevent teratogenicity, a comprehensive program has been established to control access to the drug, including registration of prescribing physicians, dispensing pharmacies, and patients; mandatory informed consent and education procedures; and limitation of the quantity of drug dispensed. Clinical and, in some patients, electrophysiologic monitoring for peripheral neuropathy is indicated with thalidomide therapy. Other adverse effects include sedation and constipation. With appropriate safeguards, thalidomide may benefit patients with a broad variety of disorders for which existing treatments are inadequate.

Achievements in Understanding and Treatment of Myelodysplastic Syndromes

The myelodysplastic syndromes (MDS) constitute a challenge for the biologist as well as for the treating physician. In Section I, Dr. Willman reviews the current classifications and disease mechanisms involved in this heterogeneous clonal hematopoietic stem cell disorder. A stepwise genetic progression model is proposed in which inherited or acquired genetic lesions promote the acquisition of “secondary” genetic events mainly characterized by gains and losses of specific chromosome regions. The genetic risk to develop MDS is likely multifactorial and dependent on various constellations of risk-producing and -protecting alleles. In Section II Dr. Barrett with Dr. Saunthararajah addresses the immunologic factors that may act as important secondary events in the development of severe pancytopenia. T cells from patients with MDS may suppress autologous erythroid and granulocytic growth in vitro, and T cell suppression by antithymocyte globulin or cyclosporine may significantly improve cytopenia, especially in refractory anemia. Recent studies have also demonstrated an increased vessel density in MDS bone marrow, and a phase II trial of thalidomide showed responses in a subgroup of MDS patients especially in those with low blast counts. In Section III Dr. Hellström-Lindberg presents results of allogeneic and autologous stem cell transplantation (SCT), intensive and low-dose chemotherapy. The results of allogeneic SCT in MDS are slowly improving but are still poor for patients with unfavorable cytogenetics and/or a high score according to the International Prognostic Scoring System. A recently published study of patients between 55-65 years old showed a disease-free survival (DFS) at 3 years of 39%. Consolidation treatment with autologous SCT after intensive chemotherapy may result in long-term DFS in a proportion of patients with high-risk MDS. Low-dose treatment with 5-azacytidine has been shown to significantly prolong the time to leukemic transformation or death in patients with high-risk MSA. Erythropoietin and granulocyte colony-stimulating factor may synergistically improve hemoglobin levels, particularly in sideroblastic anemia. Recent therapeutic advances have made it clear that new biological information may lead to new treatment modalities and, in combination with statistically developed predictive models, help select patients for different therapeutic options.

Achievements in Understanding and Treatment of Myelodysplastic Syndromes

The myelodysplastic syndromes (MDS) constitute a challenge for the biologist as well as for the treating physician. In Section I, Dr. Willman reviews the current classifications and disease mechanisms involved in this heterogeneous clonal hematopoietic stem cell disorder. A stepwise genetic progression model is proposed in which inherited or acquired genetic lesions promote the acquisition of “secondary” genetic events mainly characterized by gains and losses of specific chromosome regions. The genetic risk to develop MDS is likely multifactorial and dependent on various constellations of risk-producing and -protecting alleles. In Section II Dr. Barrett with Dr. Saunthararajah addresses the immunologic factors that may act as important secondary events in the development of severe pancytopenia. T cells from patients with MDS may suppress autologous erythroid and granulocytic growth in vitro, and T cell suppression by antithymocyte globulin or cyclosporine may significantly improve cytopenia, especially in refractory anemia. Recent studies have also demonstrated an increased vessel density in MDS bone marrow, and a phase II trial of thalidomide showed responses in a subgroup of MDS patients especially in those with low blast counts. In Section III Dr. Hellström-Lindberg presents results of allogeneic and autologous stem cell transplantation (SCT), intensive and low-dose chemotherapy. The results of allogeneic SCT in MDS are slowly improving but are still poor for patients with unfavorable cytogenetics and/or a high score according to the International Prognostic Scoring System. A recently published study of patients between 55-65 years old showed a disease-free survival (DFS) at 3 years of 39%. Consolidation treatment with autologous SCT after intensive chemotherapy may result in long-term DFS in a proportion of patients with high-risk MDS. Low-dose treatment with 5-azacytidine has been shown to significantly prolong the time to leukemic transformation or death in patients with high-risk MSA. Erythropoietin and granulocyte colony-stimulating factor may synergistically improve hemoglobin levels, particularly in sideroblastic anemia. Recent therapeutic advances have made it clear that new biological information may lead to new treatment modalities and, in combination with statistically developed predictive models, help select patients for different therapeutic options.

Mycoplasma fermentans-induced inflammatory response of astrocytes: selective modulation by aminoguanidine, thalidomide, pentoxifylline and IL-10

Exposure of primary rat glial cells, mostly astrocytes, to heat-inactivated Mycoplasma fermentans triggers the production of tumor necrosis factor alpha (TNFalpha) nitric oxide (NO) and prostaglandin E2 (PGE2). To attenuate the production of these proinflammatory mediators, four agents: aminoguanidine, pentoxifylline, thalidomide and IL-10 were added to astrocyte cultures. Aminoguanidine (1 and 3 mM), an inhibitor of inducible nitric oxide synthase (iNOS), suppressed the production of the three mediators. TNFalpha was the most sensitive to thalidomide, showing dose-response inhibition at concentrations of 20 microg/ml, 50 microg/ml and 250 microg/ml. PGE2 was affected only by concentrations of 50 microg/ml and 250 microg/ml, whereas NO responded solely to the highest amount of this inhibitor. The cytokine IL-10, at 10 U and 50 U, inhibited only TNFalpha production. Our results imply that selective suppression of proinflammatory mediators by various agents may prove feasible for amelioration of central nervous system inflammatory diseases.

Antiangiogenic therapy of human esophageal cancers with thalidomide in nude mice

BACKGROUND

Thalidomide (alpha-N-phthalimidoglutarimide) is attracting new attention because of its antiangiogenic effect in corneal neovascularization models. However, the effect of this agent on esophageal carcinoma is yet to be established.

METHODS

The human esophageal squamous cell carcinoma strains ES63 and ES80 implanted subcutaneously in nude mice were used to evaluate the antiangiogenic effect of thalidomide (200 mg/kg/d) after daily gavage or intraperitoneal administration. Tumor size was measured, and assessment of microvessel density was performed histochemically with Griffonia simplicifolia lectin I. Characterizations of angiogenic growth factors, vascular endothelial growth factor, basic fibroblast growth factor, and thymidine phosphorylase in ES63 and ES80 tumors were done by immunohistochemical staining and reverse transcription-polymerase chain reaction.

RESULTS

ES63 strongly expressed 3 angiogenic factors, but ES80 showed moderate expression of thymidine phosphorylase and only weak or no expression of vascular endothelial grown factor and basic fibroblast growth factor at protein and messenger RNA levels. In ES63 intraperitoneal injection of thalidomide produced significant (P < .05) inhibition of tumor growth, but there was no effect after gastric gavage. Also, a significantly (P < .0005) lower microvessel density was encountered in the intraperitoneal thalidomide group. However, in the ES80 tumor strain thalidomide had no antiangiogenic effect after either intraperitoneal or oral administration.

CONCLUSIONS

These data indicate that thalidomide exerts an antiangiogenic effect on solid tumor after intraperitoneal administration. Thalidomide might be one of the hopeful antiangiogenic drugs for solid tumors.

Tumor necrosis factor-alpha production by human hepatoma cell lines is resistant to drugs that are inhibitory to macrophages

Little is known about the potential of immunomodulatory agents to lower tumor necrosis factor-alpha (TNF-alpha) synthesis in tissues of nonmonocytic origin. We studied effects of diverse drugs on the formation of immunoreactive TNF-alpha in the human hepatoma cell lines HepG2 and Hep3B, in which TNF-alpha production was induced by treatment (3 h incubation periods) with interleukin-1beta (IL-1beta, 300 pg/ml) or phorbol myristate acetate (PMA, 100 nmol/l). TNF-alpha production in IL-1beta-stimulated or PMA-stimulated hepatocyte cultures was not altered following the addition of dihydrocortisone (< or = 1 microg/ml), dibutyryl-cAMP (db-cAMP, < or = 100 micromol/l), adenosine (< or = 1 mmol/l), thalidomide (< or = 25 microg/ml), or cyclosporine (< or = 300 ng/ml). TNF-alpha production was inhibited by taurolidine (> or = 300 microg/ml), but this inhibition was associated with reduced cell viability. Pentoxifylline (1 mg/ml) did not influence PMA-induced TNF-alpha production, but it augmented IL-1beta-induced TNF-alpha production. Measurements of TNF-alpha mRNA by RT-PCR indicated that pentoxifylline exerted its effect posttranscriptionally. Additional studies with PMA-treated human whole blood cultures confirmed that pentoxifylline, db-cAMP, and adenosine reduced TNF-alpha production by leukocytes. These results provide first evidence to assume cell type-specific effects of immunomodulatory drugs on TFN-alpha synthesis, which may be relevant with respect to their clinical application.

Thalidomide and its impact in dermatology

Thalidomide, originally marketed as a sedative, was introduced in West Germany in 1956 and in numerous other countries soon thereafter. In part because it did not impair coordination or respiratory function, the drug rapidly became extremely popular. By 1961, however, there were mounting reports of phocomelia and other severe congenital abnormalities associated with maternal use of thalidomide, and the drug was withdrawn from the market and its availability highly restricted. A few years later, thalidomide would find use in dermatology after it was reported that leprosy patients with erythema nodosum leprosum (ENL) experienced rapid and dramatic improvement after taking the drug as a sedative. Additional data quickly confirmed thalidomide's efficacy in ENL, and today it is the drug of choice in the condition. In subsequent decades, the drug has been successfully tried in treatment of a variety of apparently unrelated dermatologic disorders. Meanwhile, thalidomide has been shown to possess a range of biologic actions, including inhibition of tumor necrosis factor alpha, possibly relevant to its clinical efficacy. Dermatologic disorders in addition to ENL in which thalidomide's effectiveness is well documented include aphthous stomatitis, discoid lupus erythematosus, actinic prurigo, Behçet's disease, and prurigo nodularis. More recently, the drug has been employed in dermatologic conditions associated with HIV infection. When used with safeguards to prevent teratogenicity and the drug's other major adverse effect, peripheral neuropathy, thalidomide may offer a good therapeutic option for many patients in whom other drug therapies have proven inadequate.

Randomised comparison of thalidomide versus placebo in toxic epidermal necrolysis

BACKGROUND

Toxic epidermal necrolysis (TEN) is associated with a 30% death rate. Tumour necrosis factor alpha (TNF-alpha) has been implicated in the pathogenesis of TEN. Thalidomide is a potent inhibitor of TNF-alpha action. We did a double-blind, randomised, placebo-controlled study of thalidomide in TEN.

METHODS

The patients received a 5-day course of thalidomide 400 mg daily or placebo. The main endpoint was the progression of skin detachment after day 7. Secondary endpoints were the severity of the disease, evaluated with the simplified acute physiology score (SAPS), and the mortality. TNF-alpha and interleukin 6 were measured.

FINDINGS

The study was stopped because there was excess mortality in the thalidomide group--ten of 12 patients died compared with three of ten in the placebo group (Fisher's exact test with Katz's approximation, relative risk=2.78, p=0.03). After adjustment for SAPS, mortality remained significantly higher in the thalidomide group than in the placebo group (exact logistic regression mid-p=0.007; 95% CI for odds ratio 2.7 to infinity). Plasma TNF-alpha concentration was higher in the thalidomide group than the placebo group on day 2, though the difference was not significant (Wilcoxon rank-sum test p=0.07).

INTERPRETATION

Even though few patients were included, our data suggest that thalidomide is detrimental in TEN, possibly because of a paradoxical enhancement of TNF-alpha production.

Thalidomide prolongs experimental autoimmune neuritis in Lewis rats

Thalidomide is reported to have immunomodulatory and anti-inflammatory effects, which have led to its use in the treatment of a number of immune-mediated disorders, including leprosy, discoid lupus and Behcet's disease, and to prevent immunological rejection phenomena following skin and bone marrow grafts. Experimental autoimmune neuritis (EAN) is a CD4+ T-cell-mediated demyelinating autoimmune disease, which represents an animal model for the study of the immunopathogenesis and immunotherapy of Guillain-Barré syndrome (GBS) in humans. We examined the effect of thalidomide in Lewis rats with EAN, which was induced by immunization with bovine peripheral nerve myelin (BPM) and complete Freund's adjuvant (CFA). Thalidomide prolonged clinical EAN when given at a dose of 200 mg/kg/day by gavage. This clinical effect was associated with increased numbers of inflammatory cells in sciatic nerve sections and elevated numbers of interferon-gamma (IFN-gamma) mRNA-expressing cells among lymph node mononuclear cells from thalidomide-treated EAN rats on day 17 postimmunization, i.e. at the peak of clinical EAN. The finding that thalidomide prolongs clinical EAN is in agreement with the clinical polyneuropathy reported in patients receiving treatment with thalidomide and limits its clinical usefulness.

Molecular basis of a new type of C1q-deficiency associated with a non-functional low molecular weight (LMW) C1q: parallels and differences to other known genetic C1q-defects

Analysis of an abnormal C1q molecule of individuals of a Moroccan family by ultracentrifugation in sucrose gradients revealed a low molecular weight C1q (LMW-C1q). We investigated the molecular basis of this defect by sequencing all six exons of the three C1q genes. One point mutation in the codon for Gly at position 15 (GGT) of the B chain was found resulting in an amino acid substitution to Asp (GAT). The exchange not only leads to an interruption of the collagen-like motif Gly-X-Y, but also introduces one negatively charged residue per B chain which results in two additional charges per structural subunit (A-B, C-C, A-B). The mutation which has been identified by DNA-sequencing in the C1q-deficient younger brother of the propositus was confirmed by PCR-EcoRV-RFLP in the sister and the propositus himself. This mutation is very similar to a mutation previously described in another case of functional C1q deficiency where Gly at position 6 of the C chain was substituted by a large positively charged residue (Arg). Again, a LMW-C1q was demonstrated. These point mutations that lead to amino acid substitutions result in the production of a LMW-C1q where the formation of functionally active 11S C1q consisting of three structural subunits appears to be inhibited by the introduction of six additional charges, one per B or C chain, respectively, in the collagenous region of the molecule.

Thalidomide protects mice against LPS-induced shock

Thalidomide has been shown to selectively inhibit TNF-alpha production in vitro by lipopolysaccharide (LPS)-stimulated monocytes. TNF-alpha has been shown to play a pivotal role in the pathophysiology of endotoxic shock. Using a mouse model of LPS-induced shock, we investigated the effects of thalidomide on the production of TNF-alpha and other cytokines and on animal survival. After injection of 100-350 micrograms LPS into mice, cytokines including TNF-alpha, IL-6, IL-10, IL-1 beta, GM-CSF and IFN-gamma were measured in the serum. Administration of 200 mg/kg thalidomide to mice before LPS challenge modified the profile of LPS-induced cytokine secretion. Serum TNF-alpha levels were reduced by 93%, in a dose-dependent manner, and TNF-alpha mRNA expression in the spleens of mice was reduced by 70%. Serum IL-6 levels were also inhibited by 50%. Thalidomide induced a two-fold increase in serum IL-10 levels. Thalidomide treatment did not interfere with the production of GM-CSF, IL-1 beta, or IFN-gamma. The LD50 of LPS in this model was increased by thalidomide pre-treatment from 150 micrograms to 300 micrograms in 72 h. Thus, at otherwise lethal doses of LPS, thalidomide treatment was found to protect animals from death.

In vitro and in vivo immunosuppressive potential of thalidomide and its derivative, N-hydroxythalidomide, alone and in combination with cyclosporin A

Thalidomide (Thd) has been shown to have interesting immunosuppressive properties and strong action against TNF-alpha. It is used for treating a variety of immune-mediated pathology and inflammatory diseases. The purpose of this work was to evaluate the in vitro and in vivo immunosuppressive effects of Thd and its derivative, N-Hydroxythalidomide (H-Thd), alone and in combination with cyclosporin A (CsA), upon different in vitro lymphocyte activation pathways and in vivo local graft-versus-host-reaction (GvHR). At different concentrations, both Thd and H-Thd alone inhibited the lymphocyte proliferation induced by alloantigen (MLR), mitogens (Con A, PWM) and superantigen (SEB) with an activity of 50-75% that of CsA, however, in some tests, immunosuppressive potency of H-Thd was shown to be higher than that of Thd. In vivo using GvHR, Thd and H-Thd alone proved as active as CsA. The association in vitro and in vivo of each compound with CsA at different low concentrations, produced an additive effect as strong as CsA used alone at high therapeutic concentrations. In summarizing, this study revealed that: (1) despite its weaker potency in vitro than that of CsA, H-Thd presents interesting immunosuppressive properties similar to, and in some cases, better than Thd, and (2) the combination of H-Thd or Thd with CsA at suboptimal concentrations leads to high activity.