UNION therapeutics’ Orismilast is a high potency, next-generation PDE4 inhibitor with broad anti-inflammatory properties also in development for oral treatment of atopic dermatitis (AD) and psoriasis.

Oral orismilast is showing promise in adult with hidradenitis suppurativa (HS), according to positive topline results from the OSIRIS investigator-initiated proof-of-concept study.

UNION therapeutics’ Orismilast is a high potency, next-generation PDE4 inhibitor with broad anti-inflammatory properties also in development for oral treatment of atopic dermatitis (AD) and psoriasis. The US Food and Drug Administration 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 as well as for the treatment of moderate to severe HS. In 2021, UNION entered a strategic partnership with Innovent Biologics for the development of orismilast in Mainland China, Hong Kong, Macau, and Taiwan.

The new study demonstrated clinically relevant improvements in HS for patients who completed the planned 16 weeks of treatment with oral orismilast including reduction of pain (Global Pain Assessment) and improvement in patient-reported quality of life (DLQI). Most responders had moderate or severe HS at baseline, including several prior failures to biologics treatment.

The conclusion on the doses explored is consistent with the findings from the subsequent IASOS Phase 2b dose-finding study in psoriasis recently reported. The target product profile of oral orismilast was confirmed including the well-established favorable safety profile of PDE4 inhibition.

"Hidradenitis suppurativa is an inflammatory systemic skin disease where a strong unmet need remains for safe and effective oral treatments. Patients suffer from pain discharge and scarring of intimate skin areas. The positive topline data from the OSIRIS study are very encouraging," says study author Professor Gregor B. Jemec, PhD, MD, Founding Chairman of the Department of Dermatology, Zealand University Hospital Roskilde, Denmark, in a news release.

Kim Kjøller, Chief Executive Officer of UNION therapeutic, adds: "We are delighted to see positive topline results from the OSIRIS study. The results are very encouraging, including not least seeing patients in this difficult to treat patient population achieving HiSCR90 and HiSCR100 response. Equally important, patients experienced significant reduction in pain, which is a great burden for patients with HS, and most responders had moderate or severe HS at baseline, including several prior failures to biologics treatment. The study supports the target product profile of orismilast as a high-potency PDE4 inhibitor consistent with the recent IASOS Phase 2b study in psoriasis. We are looking forward to advancing orismilast in HS and will engage with the regulatory authorities around the best path to approval."

The results will be presented by the sponsoring investigator at an upcoming scientific conference, and UNION expects to further progress the development of oral orismilast in HS.