A Study to Assess the Efficacy and Safety of Dupilumab in Participants With Severe Atopic Dermatitis (AD) That Are Not Controlled With Oral Cyclosporine A (CSA) or for Those Who Cannot Take Oral CSA Because it is Not Medically Advisable

Inclusion Criteria

• Male or female, 18 years or older
• Severe, Chronic AD, (according to American Academy of Dermatology Consensus Criteria [Eichenfield 2014]) for whom treatment with potent TCS is indicated
• EASI score ≥20 at the screening and baseline visits
• IGA score ≥3 (on the 0 to 4 IGA scale) at the screening and baseline visits
• ≥10% body surface area (BSA) of AD involvement at the screening and baseline visits
• Documented recent history (within 6 months before the screening visit) of inadequate response to treatment with TCS
• Have applied a stable dose of topical emollient (moisturizer) twice daily for at least the 7 consecutive days immediately before the baseline visit
• Documented history by a physician of either:
• No prior CSA exposure and not currently a candidate for CSA treatment due to:
• medical contraindications (eg, uncontrolled hypertension on medication), or
• use of prohibited concomitant medications (eg, statins, digoxin, macrolide, antibiotics, barbiturates, anti-seizure, nonsteroidal anti-inflammatory drugs, diuretics, angiotensin-converting-enzyme inhibitors, St John's Wort, etc), or
• increased susceptibility to CSA-induced renal damage (elevated creatinine) and liver damage (elevated function tests), or
• increased risk of serious infections, or
• hypersensitivity to CSA active substance or excipients OR
• Previously exposed to CSA, and CSA treatment should not be continued or restarted due to:
• intolerance and/or unacceptable toxicity (eg, elevated creatinine, elevated liver function tests, uncontrolled hypertension, paraesthesia, headache, nausea, hypertrichosis, etc), or
• inadequate response to CSA (defined as flare of AD on CSA tapering after a maximum of 6 weeks of high dose [5 mg/kg/day] to maintenance dose [2 to 3 mg/kg/day] or a flare after a minimum of 3 months on maintenance dose). Flare is defined as increase in signs and/or symptoms leading to escalation of therapy, which can be an increase in dose, a switch to a higher-potency class of TCS, or the start of another systemic non-steroidal immunosuppressive drug or
• requirement for CSA at doses >5 mg/kg/day, or duration beyond those specified in the prescribing information (>1 year)

Exclusion Criteria

• Participation in a prior dupilumab clinical study
• Treatment with an investigational drug within 8 weeks or within 5 half-lives (if known), whichever is longer, before the screening visit
• Hypersensitivity and/or intolerance to corticosteroids or to any other ingredients contained in the TCS product used in the study
• Systemic CSA, systemic corticosteroids, or phototherapy within 4 weeks prior to screening, and azathioprine (AZA), methotrexate (MTX), mycophenolate mofetil (MMF), or Janus kinase (JAK) inhibitors within 8 weeks prior to screening
• Treatment with TCI within 1 week before the screening visit
• Treatment with biologics as follows:
• Any cell-depleting agents including but not limited to rituximab: within 6 months before the screening visit, or until lymphocyte count returns to normal, whichever is longer
• Other biologics: within 5 half-lives (if known) or 16 weeks prior to the screening visit, whichever is longer
• Regular use (more than 2 visits per week) of a tanning booth/parlor within 4 weeks of the screening visit
• Treatment with a live (attenuated) vaccine within 12 weeks before the screening
• Active chronic or acute infection requiring treatment with systemic antibiotics, antivirals, antiparasitics, antiprotozoals, or antifungals within 2 weeks before the screening or superficial skin infections within 1 week before the screening visit. NOTE: patients may be rescreened no sooner than 2 weeks after infection resolves
• Known or suspected history of immunosuppression, including history of invasive opportunistic infections (eg, tuberculosis [TB], histoplasmosis, Listeriosis, coccidioidomycosis, pneumocystosis, aspergillosis) despite infection resolution; or unusually frequent,