Oral orismilast is also in development for treatment of atopic dermatitis and hidradenitis suppurativa.

Oral orismilast performed well in adult patients with moderate to severe psoriasis, according to topline results from the IASOS Phase 2b study.

Data from the 202 patients randomized and dosed in the study showed that all active arms of oral orismilast achieved the primary endpoint of percentage change in Psoriasis Activity and Severity Index (PASI) from baseline to week 16 measured against placebo, with statistical significance reached already at the first time point after 4 weeks of treatment, UNION therapeutics reports. The results support the target product profile of a best-in-class PDE4 inhibitor and confirm the well-established favorable safety profile of PDE4 inhibition.

Orismilast has been developed as a more potent PDE4-inhibitor targeting a best-in-class position. This has been demonstrated in multiple preclinical and human biomarker studies and is now further supported by secondary endpoints from the IASOS study, including PASI-90 and PASI-100.

UNION plans to present topline data at an upcoming dermatology conference.

"A strong unmet need remains for oral medicines in psoriasis, as many patients are undertreated or are dissatisfied with current options,” says lead investigfaror Prof. Richard Warren, MBChB (hons), PhD, The University of Manchester and Consultant Dermatologist, Salford Royal NHS Foundation Trust, in a news release. “The promising topline data from the IASOS study illustrates that selective potent PDE4 inhibition by orismilast offers the potential for additional efficacy in combination with a well-known safety profile from the PDE4 class."

About the IASOS Phase 2b study

The Phase 2b study is a randomized, double-blind, placebo-controlled, parallel-group, dose-ranging study to evaluate the efficacy and safety of orismilast MR tablet in adult patients with moderate to severe plaque psoriasis. The study included 202 patients randomized to receive 1 of 3 active doses or placebo administered twice daily. The study was conducted at clinical sites in the US, the UK, Germany, and Poland.

About orismilast

UNION is developing orismilast, a high-potency PDE4 inhibitor targeting the PDE4 subtypes linked to inflammation. It operates early in the inflammation cascade, inducing a broad range of anti-inflammatory effects across multiple cytokines involved in many dermatological and immunological diseases.1)

Orismilast holds the potential to become a safe and efficacious oral treatment for many immunological diseases, and UNION is currently developing oral orismilast for the treatment of AD, psoriasis, and HS.

The FDA has cleared UNION's Investigational New Drug (IND) application for oral orismilast and granted Fast Track designation for oral orismilast for the treatment of moderate to severe AD. In 2021, UNION entered a strategic partnership with Innovent Biologics for the development of orismilast in Mainland China, Hong Kong, Macau, and Taiwan.