New class of inhibitors specific for human renin

Renin inhibitors

Since the early 1980s, an intensive effort has been focused on the development of orally effective and long-acting inhibitors of renin. During this time, in vitro potency has increased greatly, with several transition-state inhibitor designs yielding inhibitors with subnanomolar IC50 values. In the meantime, both the molecular weight and peptide character of the inhibitors has decreased as important binding elements have been focused into smaller and more stable structures. The resulting inhibitors have shown promising activities in several in vivo models and (in two cases) in man. Nevertheless, renin inhibitors reported to date have limited oral bioavailability and short duration of action, and improvements in both will be necessary for them to compete effectively with ACE inhibitors. Renin inhibitors which have entered clinical studies have at least one naturally occurring amino acid and three or more amide bonds. It is reasonable to expect that continued development will produce wholly nonpeptide inhibitors with still lower MW, and it may be these "second-generation" inhibitors which will succeed as therapeutic agents. Development of orally effective and long-acting inhibitors of renin will enable their long-term antihypertensive efficacy and possible advantages over ACE inhibitor to be investigated.

Renin inhibitors

Pharmacological intervention in the renin-angiotensin system (RAS) by inhibition of angiotensin-converting enzyme (ACE) is an effective therapy for the majority of hypertensive patients and a major advance in the treatment of hypertension and congestive heart failure. The success achieved with ACE inhibitors has increased interest in inhibitors of renin. Renin catalyzes the first and rate-limiting step of the RAS and, unlike ACE, has a high specificity for its endogenous protein substrate. A therapeutic agent that inhibits this specific reaction could have advantages over antihypertensive drugs with less specific modes of action. Although inhibitors of renin have been studied for over two decades, only recently has substantial progress been made toward potent, low molecular weight inhibitors likely to become useful therapeutic agents. Recent advances in the development of renin inhibitors, especially progress toward clinically useful inhibitors, is reviewed.