Design and evaluation of a novel series of 2,3-oxidosqualene cyclase inhibitors with low systemic exposure, relationship between pharmacokinetic properties and ocular toxicity

We describe the discovery of novel potent inhibitors of 2,3-oxidosqualene:lanosterol cyclase inhibitors (OSCi) from a focused pharmacophore-based screen. Optimization of the most tractable hits gave a series of compounds showing inhibition of cholesterol biosynthesis at 2 mg/kg in the rat with distinct pharmacokinetic profiles. Two compounds were selected for toxicological study in the rat for 21 days in order to test the hypothesis that low systemic exposure could be used as a strategy to avoid the ocular side effects previously described with OSCi. We demonstrate that for this series of inhibitors, a reduction of systemic exposure is not sufficient to circumvent cataract liabilities.