Funding

The ECZTRA 1, ECZTRA 2, and ECZTEND trials were sponsored by LEO Pharma A/S (Ballerup, Denmark).

Conflicts of Interest/Competing Interests

Raj Chovatiya has served as an advisor, consultant, speaker, and/or investigator for AbbVie, Amgen, AnaptysBio, Apogee Therapeutics, Arcutis, Argenx, Beiersdorf, Boehringer Ingelheim, Bristol Myers Squibb, Cara Therapeutics, CLn Skin Care, Dermavant, Eli Lilly and Company, EMD Serono, FIDE, Formation Bio, Galderma, Genentech, GSK, Johnson & Johnson, Incyte, LEO Pharma, L’Oréal, Nektar Therapeutics, Novartis, Opsidio, Pfizer Inc., RAPT, Regeneron, Sanofi, Sitryx, Takeda, TRex Bio, and UCB. Raj Chovatiya is an Editorial Board member of the American Journal of Clinical Dermatology. He was not involved in the selection of peer reviewers for the manuscript nor any of the subsequent editorial decisions. Simone Ribero received research grants, personal fees, or non-financial support from AbbVie, Almirall, BMS, Galderma, LEO Pharma, Lilly, L’Oreal, Novartis, Pfizer, Pierre Fabre, and Sanofi. Andreas Wollenberg has served as an advisor or paid speaker for, or participated in clinical trials (with honoraria paid to the institution) sponsored by AbbVie, Aileens, Almirall, Amgen, Beiersdorf, Bioderma, Bioproject, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Chugai, DKSH, Eli Lilly, Galapagos, Galderma, Glenmark, GSK, Hans Karrer, Hexal, Janssen-Cilag, Kyowa Kirin, LEO Pharma, L’Oreal, Maruho, MedImmune, MSD, Mylan, MSD, Novartis, Pfizer, Pierre Fabre, Regeneron, Sandoz, Santen, Sanofi-Aventis, and UCB. Chang Ook Park is an investigator for Sanofi, Pfizer, Galderma, Eli Lilly, LEO Pharma, Amgen, AstraZeneca, GSK, Kiniksa Pharmaceuticals, and Teva Pharmaceuticals. Juan Francisco Silvestre has served as an investigator and/or speaker and/or advisor for following pharmaceutical companies: AbbVie, Almirall-Hermal, Amgen, AstraZeneca, Eli-Lilly, Galderma, LEO Pharma, Incyte, Novartis, Pfizer, Regeneron, and Sanofi-Genzyme. H. Chih-ho Hong is a researcher, consultant, and/or advisor for AbbVie, Amgen, Arcutis, Aslan, Bausch Health, Boehringer Ingelheim, Bristol Meyers Squibb, Celgene, Dermavant, Dermira, DS Biopharma, Eli Lilly, Evelo, Galderma, GlaxoSmithKline, Incyte, Janssen, LEO Pharma, MedImmune, Novartis, Pfizer, Regeneron, Roche, Sanofi Genzyme, Sun Pharma, and UCB. Julien Seneschal has served as an investigator, speaker, and/or advisor for Abbvie, Almirall, Eli Lilly, Galderma, Janssen, LEO Pharma, Novartis, Pfizer, and Sanofi‐Genzyme. Hidehisa Saeki received lecture fees and/or clinical research funding and/or grant donations from Mitsubishi Tanabe Pharma Corporation, Taiho Pharmaceutical Co., Ltd., AbbVie GK, Sanofi K.K., Torii Pharmaceutical Co. Ltd., Maruho Co., Ltd., Japan Tobacco Inc., Eli Lilly Japan K.K., LEO Pharma K.K., Otsuka Pharmaceutical Co., Ltd., Novartis Pharma K.K, Pfizer Japan Inc., Amgen Inc., Eisai Co., Ltd., and Tokiwa Pharmaceutical Co., Ltd. Jacob P. Thyssen is an employee of LEO Pharma and holds stock options, and served previously as an advisor for AbbVie, Almirall, Arena Pharmaceuticals, Coloplast, OM Pharma, Aslan Pharmaceuticals, Union Therapeutics, Eli Lilly & Co, Pfizer, Regeneron, and Sanofi-Genzyme; a speaker for AbbVie, Almirall, Eli Lilly & Co, Pfizer, Regeneron, and Sanofi Genzyme; and received research grants from Pfizer, Regeneron, and Sanofi Genzyme. Christian Bjerregård Øland is a former employee of LEO Pharma A/S. Le Gjerum and Douglas Maslin are employees and shareholders of LEO Pharma A/S. 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 Pharma, and Union, 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 Pharma, and owns stock in Lipidio and Oruka.

Ethics Approval

The ECZTRA 1, ECZTRA 2, 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 Harmonisation guidelines for Good Clinical Practice. The clinical trials were approved by institutional review boards or ethics committees at each study site. These trials followed the Consolidated Standards of Reporting Trials reporting guideline.

Consent to Participate

All patients provided written informed consent.

Consent for Publication

Not applicable.

Availability of Data and Material

Data will be made available, upon request to the study sponsor, following review by the external patient and the scientific review board.

Code Availability

Not applicable.

Authors’ Contributions

Conceptualization: all authors contributed equally; investigation: all authors contributed equally; data curation: CBØ; formal analysis: CBØ (lead); methodology: CBØ (equal), DM (equal); writing: all authors contributed equally; review/editing: all authors contributed equally. All authors read and approved the final version of the manuscript.