Hellerup, Denmark, November 16, 2023 – UNION therapeutics A/S (UNION), a privately-held, clinical stage, pharmaceutical development company focused on immunology and infectious diseases, announces that it has completed enrollment of the last patient (n=235) in the ADESOS, Phase 2b dose-ranging study evaluating the safety and efficacy of orismilast in patients with moderate to severe AD. UNION expects to report topline data from this study in the first half of 2024.

Earlier this year, UNION reported positive topline results from the IASOS Phase 2b study of orismilast in psoriasis and from the investigator-initiated OSIRIS proof-of-concept study of orismilast in HS.

Jonathan Silverberg, MD, PhD, MPH, Professor of Dermatology at The George Washington University School of Medicine and Health Sciences and Signatory Investigator for ADESOS study adds: 

“AD is one of the most common chronic inflammatory skin diseases worldwide. Despite recent advancements in the treatment of AD, there are still unmet needs for safe and effective oral treatments. Orismilast hold significant promise as a novel and patient-friendly treatment option in AD.”


Kim Kjøller, Chief Executive Officer of UNION therapeutics said:

“Orismilast holds the potential to become a first-in-class oral treatment of atopic dermatitis, and hereby become an efficacious oral treatment option for patients who need systemic therapy in atopic dermatitis. The completion of patient enrollment for the ADESOS study marks the continued important advancement of UNION’s pipeline.” 


About the ADESOS Phase 2b study

The Phase 2b study is a randomized, double-blind, placebo-controlled, parallel-group, dose-finding study to evaluate the efficacy and safety of orismilast in patients with moderate to severe AD. The study included 235 patients who were randomized to three active doses (20mg, 30mg, and 40 mg) of orismilast or placebo administered twice daily. The study is conducted in centers in Europe and in the US.

About orismilast

Orismilast is a next generation, high potency PDE4B/D selective inhibitor targeting the PDE4B/D subtypes linked to inflammation, demonstrating potent inhibition of Th1, Th2 and Th17 pathways. It acts early in the inflammation cascade, inducing a broad range of anti-inflammatory effects across multiple cytokines involved in many dermatological and immunological diseases.1)

UNION is developing orismilast as an efficacious oral treatment, with the well-known safety profile of the PDE4 class, across immunology, initially targeting best-in-class or first-in-class positions in atopic dermatitis, hidradenitis suppurativa and psoriasis.

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.

About atopic dermatitis

AD is a chronic inflammatory skin disease affecting 2.1-4.9 % of the adult population worldwide and is the most common skin disease among children.2) There was approximately 20 million diagnosed moderate-to-severe adult patients with AD in 2023 in the Seven Major Markets (US, France, Germany, Italy, Spain, UK, and Japan).3) Disease symptoms are characterized by recurrent eczematous skin lesions and intense itch. AD has a substantial psychosocial impact on patients and relatives.4) During disease flares, approximately 80% of patients may experience disturbed sleep, which may also disrupt the sleep of family members.5) The disease also appears to impact the mood and patients have an increased risk of anxiety and depression.6)


1)       Blauvelt A et al., Dermatology and Therapy 2023: Next Generation PDE4 Inhibitors that Selectively Target PDE4B/D Subtypes: A Narrative Review – PubMed (nih.gov) &

Silverberg J.I. et al., JEADV 2022: https://onlinelibrary.wiley.com/doi/10.1111/jdv.18818  &

Warren R.B. et al., JEADV 2022: https://onlinelibrary.wiley.com/doi/10.1111/jdv.18812

2)       Barbarot S et al,. Allergy 2018: https://pubmed.ncbi.nlm.nih.gov/29319189/ https://pubmed.ncbi.nlm.nih.gov/25925336/

3)       EvaluatePharma 2023

4)       Laughter MR et al., British Journal of Dermatology 2021: https://pubmed.ncbi.nlm.nih.gov/33006135/

5)       Eichenfield LF et al., Journal of the American Academy of Dermatology 2014: https://pubmed.ncbi.nlm.nih.gov/24290431/

6)       Drucker AM et al., The Journal of Investigative Dermatology 2017: https://pubmed.ncbi.nlm.nih.gov/27616422/



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

+45 2381 5487

[email protected]


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

+45 5385 3044

[email protected]


About UNION therapeutics

UNION therapeutics is a privately held, mid-to late-stage, pharmaceutical development company focused on advancing novel treatment options within immunology and infectious diseases. 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 http://www.uniontherapeutics.com