Biotechnology company Ascletis Pharma Inc (HKEX: 1672) on Monday reported positive topline results from a US randomised, double-blind, placebo-controlled Phase I single ascending dose study of ASC50, an oral small molecule interleukin-17 inhibitor, demonstrating favourable safety, pharmacokinetics and target engagement.

The study enrolled 46 healthy participants who received single oral doses of ASC50 ranging from 10 mg to 600 mg or placebo. ASC50 showed a dose-proportional pharmacokinetic profile across all dose levels, with elimination half-lives ranging from 43 to 104 hours, supporting once-daily and potentially once-weekly oral dosing.

Strong target engagement was observed following a single dose, evidenced by elevated plasma interleukin-17A levels that persisted up to day seven at higher doses. ASC50 was safe and well tolerated, with all adverse events reported as mild and transient, no serious adverse events, no discontinuations and no hepatic safety signals identified.

Based on these results, Ascletis has advanced ASC50 into multiple ascending dose clinical development in patients with mild to moderate plaque psoriasis. ASC50 is an in-house discovered new chemical entity with US and global patent protection through 2043.