Ascletis Receives FDA Clearance to Advance ASC50, a Novel Oral IL-17 Inhibitor, Into Phase 1 Psoriasis Trial

Ascletis Pharma, Inc. announced today that the US FDA has cleared its investigational new drug application for a phase 1 trial of its oral small molecule inhibitor targeting IL-17.¹ The drug, ASC50, will be assessed in patients with mild to moderate plaque psoriasis, with the trial evaluating its safety, tolerability, and pharmacokinetics.

Image Credit: © Milan Lipowski - stock.adobe.com

The clearance marks a step forward for the Hong Kong–based biopharmaceutical company, as ASC50 is the first oral immunology candidate derived from its proprietary Artificial Intelligence-assisted Structure-Based Drug Discovery (AISBDD) platform.

A New Oral IL-17 Inhibitor Candidate in the Pipeline

ASC50 was discovered and developed entirely in-house by Ascletis, with the aim of addressing unmet needs in autoimmune and inflammatory conditions through oral delivery formats.

The drug targets IL-17, a cytokine implicated in the pathogenesis of psoriasis and other chronic inflammatory diseases.² While IL-17 is already a well-established therapeutic target, with several monoclonal antibodies against IL-17 or its receptor (ixekizumab, secukinumab, and brodalumab) being FDA-approved for psoriasis,³ oral small molecule inhibitors are comparatively rare and present unique therapeutic advantages, according to Ascletis.

Preclinical results have exhibited promise. In non-human primates, the agent demonstrated a favorable pharmacokinetic profile when compared to an existing IL-17 oral inhibitor currently in clinical development. Specifically, ASC50 showed:

• Higher systemic exposure
• A longer half-life
• Lower clearance

In animal models of psoriasis, ASC50 also demonstrated marked efficacy, providing support for its clinical advancement.

Phase I Trial Design

The phase 1 trial will be a randomized, double-blind, placebo-controlled study conducted across multiple US sites. The trial is expected to initiate dosing in the third quarter of 2025.

AI-Driven Drug Discovery

ASC50 is the first immunology asset from Ascletis’ AISBDD platform to reach the clinic. The platform utilizes artificial intelligence to enhance the precision and speed of structure-based drug design.

"We are excited and encouraged by the preclinical data of ASC50 as it is the first oral small molecule drug candidate in immunology arisen from our Artificial Intelligence-assisted Structure-Based Drug Discovery (AISBDD) Platform," Jinzi Jason Wu, PhD, founder, chairman, and CEO of Ascletis, said in a news release.¹ "The IND clearance of ASC50 marks a new milestone for Ascletis in autoimmune and inflammatory diseases. We are continuing to work on differentiated agents including oral drugs and once-monthly or less frequent subcutaneously injectables to address unmet medical needs in multiple key therapeutics areas."

References

1. Ascletis announces US FDA clearance of IND application for its oral small molecule IL-17 inhibitor, ASC50, for the treatment of psoriasis. News release. PR Newswire. May 22, 2025. Accessed May 22, 2025. https://www.prnewswire.com/news-releases/ascletis-announces-us-fda-clearance-of-ind-application-for-its-oral-small-molecule-il-17-inhibitor-asc50-for-the-treatment-of-psoriasis-302462995.html
2. Zeichner JA, Armstrong A. The role of IL-17 in the pathogenesis and treatment of psoriasis. J Clin Aesthet Dermatol. 2016;9(6 Suppl 1):S3-S6.
3. Jeon C, Sekhon S, Yan D, Afifi L, Nakamura M, Bhutani T. Monoclonal antibodies inhibiting IL-12, -23, and -17 for the treatment of psoriasis. Hum Vaccin Immunother. 2017;13(10):2247-2259. doi:10.1080/21645515.2017.1356498