Study to Assess the Efficacy and Long-term Safety of Dupilumab (REGN668/SAR231893) in Adult Participants With Moderate-to-Severe Atopic Dermatitis

Key Inclusion Criteria

• Chronic AD that had been present for at least 3 years before the screening visit;
• Documented recent history (within 6 months before the screening visit) of inadequate response to a sufficient course of out-patient treatment with topical AD medication(s).

Key Exclusion Criteria

• Participation in a prior Dupilumab clinical trial;
• Important side effects of topical medication (e.g. intolerance to treatment, hypersensitivity reactions, significant skin atrophy, systemic effects), as assessed by the investigator or treating physician;
• Having used any of the following treatments within 4 weeks before the baseline visit, or any condition that, in the opinion of the investigator, was likely to require such treatment(s) during the first 2 weeks of study treatment:
• Immunosuppressive/immunomodulating drugs (e.g, systemic steroids, cyclosporine, mycophenolate-mofetil, Janus kinase inhibitors, interferon-gamma [IFN-γ], azathioprine, methotrexate, etc.);
• Phototherapy for AD;
• Treatment with a live (attenuated) vaccine within 12 weeks before the baseline visit;
• History of human immunodeficiency virus (HIV) infection or positive HIV serology at screening;
• Positive hepatitis B surface antigen (HBsAg), hepatitis B core antibody (HBcAb), or hepatitis C antibody at the screening visit;
• Active or acute infection requiring systemic treatment within 2 weeks before baseline visit;
• Known or suspected history of immunosuppression;
• Pregnant or breastfeeding women, or planning to become pregnant or breastfeed during the participant's participation in this study.

Note: The eligibility criteria listed above is not intended to contain all considerations relevant to a participant's potential participation in a clinical trial therefore not all inclusion/ exclusion criteria are listed.