Review Pulmonary-Allergy, Dermatological, Gastrointestinal & Arthritis: Inhibitors of TNFα synthesis

Thalidomide revisited: pharmacology and clinical applications

Thalidomide is attracting new interest. Since the discovery of its remarkable efficacy in erythema nodosum leprosum, the drug has been used successfully in a variety of dermatologic and other diseases whose apparent common thread is immune dysregulation. Meanwhile, immunomodulatory and anti-inflammatory activities of thalidomide, particularly its inhibition of tumour necrosis factor alpha (TNF-alpha), have been identified and elucidated. The drug has also been found to inhibit angiogenesis. Recent clinical trials have shown thalidomide effective in graft-versus-host disease, Behçet's syndrome and aphthous ulcers and wasting associated with HIV infection. Provocative findings in other diseases, including primary HIV infection, HIV-associated diarrhoea, inflammatory bowel disease, cancer and sepsis, have suggested additional clinical applications. Use of thalidomide in women capable of childbearing is controversial. However, guidelines have emerged for prevention of teratogenicity and peripheral neuropathy, the drug's other major adverse effect. With appropriate safeguards, thalidomide may hold benefit for patients with a broad variety of disorders in which existing treatments are inadequate. Its current use may represent only a small part of its therapeutic potential.

Transcription inhibitors in inflammation

Advances in molecular medicine have revealed a key role for altered gene expression in the aetiology of many inflammatory diseases, including asthma, rheumatoid arthritis, inflammatory bowel disease and sepsis. Until recently, however, modulation of gene transcription has not been the subject of directed pharmaceutical research efforts. Notwithstanding, it is clear that the efficacy of several well-established anti-inflammatory therapeutics is mediated through their ability to modulate gene transcription. Understanding the mechanisms of action of these therapeutics and defining new gene regulatory pathways has stimulated a new wave of anti-inflammatory drug discovery. This update aims to cover our current understanding of transcription inhibitors in inflammation, including the mechanism of action of established therapeutics and the properties of new chemical entities recently described in the literature.

Phthalazine PDE4 inhibitors. Part 3: the synthesis and in vitro evaluation of derivatives with a hydrogen bond acceptor

This communication describes the synthesis and in vitro evaluation of a novel and potent series of phthalazine phosphodiesterase type (IV) (PDE4) inhibitors. The interaction with two distinct polar binding sites allowed us to eliminate the cyclopentyloxy substitution from rolipram-like analogues.

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.

Design and synthetic considerations of matrix metalloproteinase inhibitors

Experimental evidence confirms that the matrix metalloproteinases (MMPs) play a fundamental role in a wide variety of pathologic conditions that involve connective tissue destruction including osteoarthritis and rheumatoid arthritis, tumor metastasis and angiogenesis, corneal ulceration, multiple sclerosis, periodontal disease, and atherosclerosis. Modulation of MMP regulation is possible at several biochemical sites, but direct inhibition of enzyme action provides a particularly attractive target for therapeutic intervention. Hypotheses concerning inhibition of specific MMP(s) with respect to disease target and/or side-effect profile have emerged. Examples are presented of recent advances in medicinal chemistry approaches to the design of matrix metalloproteinase inhibitors (MMPIs), approaches that address structural requirements and that influence potency, selectivity, and bioavailability. Two important approaches to the design, synthesis, and biological evaluation of MMPIs are highlighted: (1) the invention of alternatives to hydroxamic acid zinc chelators and (2) the construction of nonpeptide scaffolds. One current example in each of these two approaches from our own work is described.

2-Substituted-4-methoxybenzimidazole-based PDE4 inhibitors

A new family of PDE4 inhibitors based on a benzimidazole framework is described. Several of these compounds are orally bioavailable and show efficacy in in vivo models of inflammatory disease.