Conflict of interest

Tiffany Mayo has served as an investigator or consultant for Eli Lilly and Company, ChemoCentryx, Pfizer, Janssen, Galderma, Bristol Myers Squibb, Acelyrin, Novartis, LEO Pharma, Arcutis, and Procter & Gamble. Jonathan Silverberg reports honoraria as a consultant/advisory board member from LEO Pharma and has acted as a consultant for and/or received grants/honoraria from AbbVie, Alamar, Aldena, Amgen, AnaptysBio, AOBiome, Apollo, Arcutis, Arena, Asana Biosciences, ASLAN, Attovia, BiomX, Biosion, Bodewell, Boehringer Ingelheim, Bristol Myers Squibb, Cara Therapeutics, Castle Biosciences, Celgene, Connect Biopharma, CorEvitas, Dermavant, Eli Lilly and Company, FIDE, Galderma Research and Development, GlaxoSmithKline, Glenmark, Incyte, Inmagene, Invea, Kiniksa, LEO Pharma, MedImmune, Menlo Therapeutics, Merck, MyOr Diagnostics, Nektar, Novartis, Optum, Pfizer, PuriCore, RAPT, Recludix, Regeneron, Sandoz, Sanofi, Sanofi-Genzyme, Shaperon, TARGET RWE, Teva, Union Therapeutics, and UpToDate. April Armstrong has served as a research investigator and/or scientific advisor to AbbVie, Almirall, Arcutis, ASLAN, Beiersdorf, Boehringer Ingelheim, Bristol Myers Squibb, Dermavant, Dermira, EPI Health, Incyte, LEO Pharma, UCB, Janssen, Eli Lilly and Company, Nimbus, Novartis, Ortho Dermatologics, Sun Pharma, Dermavant, Dermira, Sanofi, Regeneron, Pfizer, and ModMed. Emma Guttman-Yassky has received honoraria for consultant services from AbbVie, Almirall, Amgen, Asana Biosciences, Boehringer Ingelheim, Cara Therapeutics, Celgene, Concert, DBV Technologies, Dermira, DS Biopharma, Eli Lilly and Company, EMD Serono, Escalier, Galderma, Glenmark, Kyowa Kirin, LEO Pharma, Mitsubishi Tanabe, Pfizer, RAPT Therapeutics, Regeneron, Sanofi, Sienna Biopharma, and Union Therapeutics; and received research grants for investigator services from AbbVie, Almirall, Amgen, AnaptysBio, Asana Biosciences, Boehringer Ingelheim, Celgene, Concert, Dermavant, Dermira, DS Biopharma, Eli Lilly and Company, Glenmark, Galderma, Innovaderm, Janssen, Kiniksa, Kyowa Kirin, LEO Pharma, Novan, Pfizer, Ralexar, Regeneron, Sienna Biopharma, UCB, and Union Therapeutics. Andrew Blauvelt has served as a speaker (received honoraria) for Eli Lilly and Company and UCB, has served as a scientific adviser (received honoraria) for AbbVie, Almirall, Alumis, Amgen, AnaptysBio, Apogee, Arcutis, Boehringer Ingelheim, Bristol Myers Squibb, Dermavant, Eli Lilly and Company, Galderma, GlaxoSmithKline, Incyte, IQVIA, Janssen, LEO Pharma, Lipidio, Merck, Novartis, Oruka, Paragon, Pfizer, Regeneron, Sanofi, Spherix Global Insights, Sun Pharma, Takeda, UCB, and Union Therapeutics; has acted as a clinical study investigator (institution has received clinical study funds) for AbbVie, Acelyrin, Almirall, Alumis, Amgen, Arcutis, Boehringer Ingelheim, Bristol Myers Squibb, Dermavant, Eli Lilly and Company, Galderma, Incyte, Janssen, LEO Pharma, Merck, Novartis, Pfizer, Regeneron, Sanofi, Sun Pharma, Takeda, and UCB; and owns stock in Lipidio and Oruka. Ben Esdaile has served either as an investigator, advisor or speaker for LEO Pharma, L’Oréal, Thornton & Ross, BIODERMA, Skin + Me, and AbbVie. Kenji Kabashima has received consulting fees or advisory board honoraria from Japan Tobacco Inc., Chugai Pharmaceutical, Maruho, and Pola Pharma; and has received research grants from LEO Pharma, Japan Tobacco Inc., Procter & Gamble Japan, Eli Lilly Japan, Mitsubishi Tanabe Pharma, ONO Pharmaceutical, Kyowa Hakko Kirin, Pola Pharma, AbbVie, Sanofi, and Kyorin Pharmaceutical. Melinda Gooderham has been an investigator, speaker and/or advisor for: AbbVie, Acelyrin, Amgen, Akros, AnaptysBio, ASLAN, Arcutis, Aristea, Bausch Health, Bristol Myers Squibb, Boehringer Ingelheim, Celgene, Dermira, Dermavant, Eli Lilly and Company, Galderma, GlaxoSmithKline, Incyte, Janssen, JAMP Pharma, Kyowa Kirin, LEO Pharma, MedImmune, Merck, Meiji, Moonlake Immunotherapeutics, Nektar, Nimbus, Novartis, Pfizer, Reistone BioPharma, Regeneron, Roche, Sanofi-Genzyme, Sun Pharma, UCB, Union Therapeutics, Ventyx, and Vyne. Leon Kircik has served either as an investigator, consultant, or speaker for AbbVie, Almirall, Amgen, Arcutis, Bausch Health Canada, Bristol Myers Squibb, Boehringer Ingelheim, Cellceutix, Celgene, Coherus, Dermavant, Dermira, Eli Lilly and Company, LEO Pharma, MC2, Maruho, Novartis, Ortho Dermatologics, Pfizer, Dr. Reddy's Laboratories, Sun Pharma, UCB, Taro, and Xenoport. Shannon Schneider is an employee of LEO Pharma Inc. Niels Bennike and Rie von Eyben are employees of LEO Pharma A/S. Mads A. Røpke was an employee of LEO Pharma A/S; current affiliation is Novo Nordisk A/S, Bagsvaerd, Denmark. Britta C. Martel is an employee and shareholder of LEO Pharma A/S. Norito Katoh has received honoraria as a speaker/consultant for Sanofi, Maruho, AbbVie, Eli Lilly Japan, Taiho Pharmaceutical, Pfizer, Otsuka Pharmaceutical, and LEO Pharma; and has received grants as an investigator from Mitsubishi Tanabe Pharma, Maruho, Torii Pharmaceutical, AbbVie, and LEO Pharma. Andrew F. Alexis has received grants (funds to institution) from LEO Pharma, Amgen, Arcutis, Dermavant, AbbVie, Castle, Incyte, and Genentech; has served as an advisory board member or consultant for LEO Pharma, Galderma, Pfizer, Sanofi-Regeneron, Dermavant, Beiersdorf, Ortho, L’Oreal, BMS, Bausch health , UCB, Arcutis, Johnson & Johnson, Allergan, Almirall, Abbvie, Amgen, VisualDx, Eli Lilly, Swiss American, Incyte, Castle, Apogee, Canfield, Alphyn, Genentech, Boehringer Ingelheim, Symrise, Novartis, HairDays, Botanix, and Alumis; served as a speaker for Regeneron, Sanofi-Genzyme, L’Oréal, Janssen, Aerolase, and Scientis; received royalties from Springer, Wiley-Blackwell, Wolters Kluwer Health, and Elsevier; and received equipment from Aerolase.

Data availability

The data underlying this article will be made available upon request to the study sponsor, following review by the external Patient and Scientific Review Board.

Ethics approval

The ECZTRA 1, 2, 3 and ECZTEND trials were sponsored by LEO Pharma A/S (Ballerup, Denmark) and conducted in accordance with the ethical principles derived from international guidelines, including the Declaration of Helsinki and Council for International Organizations of Medical Sciences International Ethical Guidelines, and in compliance with International Council for Harmonization guidelines for Good Clinical Practice. The clinical trials were approved by institutional review boards or ethics committees at each trial site. These trials followed the Consolidated Standards of Reporting Trials reporting guideline.

Patient consent

All patients provided written informed consent for participation.

Consent to publish

Not applicable.

Code availability

Not applicable.

Author contributions

Conceptualization: all authors contributed equally; data curation: Rie von Eyben; Formal Analysis: Rie von Eyben, Britta C. Martel, and Mads Røpke; funding acquisition: Shannon Schneider; investigation: all authors contributed equally; methodology: Shannon Schneider, Tiffany Mayo, Jonathan I. Silverberg, Andrew Blauvelt, Rie von Eyben, and Britta C. Martel; project administration: Shannon Schneider; resources: Shannon Schneider; software: Rie von Eyben; supervision: Shannon Schneider; validation: Rie von Eyben; visualization: Shannon Schneider; writing—original draft: all authors contributed equally; writing—review and editing: all authors contributed equally.