Discovery and development of Zetia®: Serendipity and design in the discovery of ezetimibe

MEDI 216

Duane A. Burnett, duane.burnett@spcorp.com, CV/CNS Chemical Research, Schering-Plough Research Institute, 2015 Galloping Hill Road, MS 2800, Kenilworth, NJ 07033
Lowering atherogenic LDL cholesterol in man has been shown to lower the incidence of heart disease and extend lives. While HMG-CoA reductase inhibitors have been particularly effective in this endeavor, they primarily treat endogenously synthesized cholesterol and have little impact on dietary or intestinally derived cholesterol. In our efforts to affect this second source of cholesterol, we discovered a novel class of β-lactam cholesterol absorption inhibitors that operated via an unknown mechanism. Optimization of the in vivo SAR lead to the discovery of our first clinical candidate, SCH 48461. A close examination of the metabolism of this compound revealed an important oxidative metabolite with greatly improved potency. Incorporation of this “positive metabolism” and blocking additional sites led to the discovery of ezetimibe. Ezetimibe is the first molecular entity approved for use as a cholesterol absorption inhibitor alone or in combination with statins to treat hypercholesterolemia.