Study to Determine the Safety and Effectiveness of Dupilumab (REGN668/SAR231893) for Treatment of Atopic Dermatitis (AD)

Inclusion Criteria:

1. Male or female, 18 years or older

2. Chronic AD that has been present for at least 3 years before the screening visit

3. Patients with documented recent history (within 6 months before the screening visit)
of inadequate response to outpatient treatment with topical medications, or for whom
topical treatments are otherwise inadvisable

4. Willing and able to comply with all clinic visits and study-related procedures

Exclusion Criteria:

1. Prior participation in a dupilumab clinical trial

2. Treatment with an investigational drug within 8 weeks or within 5 half-lives before
the baseline visit

3. The following treatments within 4 weeks before the baseline visit, or any condition
that, in the opinion of the investigator, will likely require such treatment(s)
during the first 4 weeks of study treatment:

- Systemic corticosteroids

- Immunosuppressive/immunomodulating drugs

- Phototherapy for AD

4. Treatment with topical corticosteroids, tacrolimus and/or pimecrolimus within 1 week
before the baseline visit

5. Treatment with certain biologics

6. Regular use (more than 2 visits per week) of a tanning booth/parlor within 4 weeks
before the baseline visit

7. Planned major surgical procedure during the patient's participation in this study

8. Patient is a member of the investigational team or his/her immediate family

9. Treatment with a live (attenuated) vaccine within 12 weeks before the baseline visit

10. Pregnant or breast-feeding women or women planning to become pregnant or breastfeed
during the study

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