• news.cision.com/
  • UNION therapeutics/
  • UNION therapeutics announces presentation of preliminary data on Phase 2a investigator-initiated study with orismilast at the 12th EHSF Conference and provides study update

UNION therapeutics announces presentation of preliminary data on Phase 2a investigator-initiated study with orismilast at the 12th EHSF Conference and provides study update

Report this content

  • Poster presentation of preliminary data from the Phase 2a investigator-initiated study OSIRIS at the 12th EHSF Conference
  • Hidradenitis suppurativa (HS) is a scarring, painful, inflammatory skin disease with few or no good treatment options
  • FDA has granted Fast Track designation to oral orismilast for treatment of moderate to severe HS
  • Orismilast is a high-potency PDE4 inhibitor with broad anti-inflammatory properties also in development for oral treatment of psoriasis and atopic dermatitis (AD)


Hellerup, Denmark, February 7, 2023 – UNION therapeutics A/S (UNION), a privately-held, multi-asset, clinical stage, pharmaceutical development company focused on immunology and infectious disease, today announced a poster presentation on new preclinical data of oral orismilast in patients with HS at the 12th European Hidradenitis Suppurativa Foundation (EHSF) conference at February 8-10, 2023, in Florence, Italy.

The preliminary data on oral orismilast is from the Phase 2a, open-label, investigator-initiated study, OSIRIS, investigating the efficacy and safety of oral orismilast for up to 16 weeks in adult patients with mild, moderate, and severe HS. Following inclusion of 20 patients, the enrollment for the study has stopped, with last patient expected to complete treatment in Q2.

Poster details

Poster title: Orismilast for mild to severe hidradenitis suppurativa: Preliminary data from OSIRIS, a Phase 2a, open-label, single-center, single-arm clinical trial

Authors: C.G. Frederiksen, F.B. Sedeh, E.H. Taudorf, D.M. Saunte, G.B.E Jemec

Kim Kjøller, Chief Executive Officer of UNION therapeutics said:

“We are encouraged that investigators will present preliminary data on orismilast for the treatment of hidradenitis suppurativa (HS) at the EHSF Conference. HS is an autoimmune systemic skin disease where, despite recent advancements in treatment, a high unmet medical need persists. The need for new treatments is also reflected in the recently granted Fast Track designation for oral orismilast for the treatment of HS.”

About HS and treatment of HS

HS is a chronic, inflammatory skin disease which results in painful inflammation of the hair follicles, most notably in the armpit and genital regions. The clinical hallmarks of the disease include very painful inflammatory nodules, boils or abscesses that typically open and release odorous inflammatory fluids. HS patients suffer primarily from pain and significant discomfort resulting from the constant formation of pus, often requiring the use of bandages and diapers, resulting in social isolation. Patients are often stigmatized by these symptoms. HS severely and adversely affects patients' quality of life and is associated with an increased overall mortality rate due to cardiovascular disease and suicides.1)

Currently, only one drug (a biologic) is approved for treatment of moderate to severe HS. For mild HS there are no treatments approved. The general standard of care for HS patients, although off-label, includes topical, oral or intravenous antibiotic treatment which often provides only temporary symptomatic relief. Antibiotics do not target the underlying inflammation and they are associated with resistance development.2)


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.3)

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 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.


1)      Ballard et al., Hidradenitis Suppurativa, StatPearls 2022: https://www.ncbi.nlm.nih.gov/books/NBK534867/ and

Thorlacius et al., Increased Suicide Risk in Patients with Hidradenitis Suppurativa, The Journal of Investigatory Dermatology, 2018: https://pubmed.ncbi.nlm.nih.gov/28942360/

2)      Saunte et al., Hidradenitis Suppurativa: Advances in Diagnosis and Treatment, JAMA, 2017: https://pubmed.ncbi.nlm.nih.gov/29183082/

3)      Silverberg J.I. et al., Pharmacology of orismilast, a potent and selective PDE4 inhibitor, JEADV 2022: https://onlinelibrary.wiley.com/doi/10.1111/jdv.18818  &

Warren R.B. et al., Efficacy and safety in moderate-severe psoriasis and development of modified release tablets, JEADV 2022: https://onlinelibrary.wiley.com/doi/10.1111/jdv.18812



Morten Boesen, Chief Financial Officer, UNION therapeutics A/S

+45 2381 5487



Sarah Toft-Jørgensen, Director of Communications and IR, UNION therapeutics A/S

+45 5385 3044



About UNION therapeutics

UNION therapeutics is a privately held, mid- to late-stage, pharmaceutical development company advancing novel treatment options within immunology and infectious diseases, two large and fast-growing therapeutic areas. UNION is headquartered in Hellerup, Denmark, and led by an international team combining biotech entrepreneurs and seasoned pharma executives, with a track record of developing and launching more than fifteen marketed drugs. Read more at www.uniontherapeutics.com



Documents & Links