Inhibitors of TACE and Caspase-1 As Anti-inflammatory Drugs

TNF-α neutralising agents such as Infliximab (Remicade®), Etanercept (Enbrel®) and the IL-1 receptor antagonist Anakinra (Kineret®), are currently used clinically for the treatment of many inflammatory diseases such as Crohn's disease, rheumatoid arthritis, ankylosing spondylitis, juvenile rheumatoid arthritis, psoriatic arthritis and psoriasis. These protein preparations are expensive to manufacture and administer, need to be injected and can cause allergic reactions. An alternative approach to lowering the levels of TNF-α and IL- 1β in inflammatory disease, is to inhibit the enzymes that generate these cytokines using cheaper small molecules. This paper is a broad overview of the progress that has been achieved so far, with respect to small molecule inhibitor design and pharmacological studies (in animals and humans), for the metalloprotease Tumour Necrosis Factor-α Converting Enzyme (TACE) and the cysteine protease Caspase-1 (Interleukin-1β Converting Enzyme, ICE). Inhibitors of these two enzymes are currently considered to be good therapeutic targets that have the potential to provide relatively inexpensive and orally bioavailable anti-inflammatory agents in the future.