Open-label Study of Dupilumab (REGN668/SAR231893) in Patients With Atopic Dermatitis

The inclusion criteria include, but are not limited to, the following:

1. Participation in a prior clinical trial of dupilumab for AD and met one of the
following:

1. Received study treatment and adequately completed the assessments required for
both the treatment and follow-up periods of the parent studies (except studies
listed in b) as defined in the parent protocols

2. Received study treatment in one the studies that have completed last patient
last visit : R668-AD-0914, R668-AD-1026, R668-AD-1117, R668-AD-1021,
R668-AD-1121, and R668-AD-1307 irrespective of duration of participation.

3. Underwent screening in R668-AD-1334 (Liberty AD SOLO 1) or R668-AD-1416 (Liberty
AD SOLO 2), but could not be randomized due to randomization closure.

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

3. Able to understand and complete study-related questionnaires

4. Provide signed informed consent

Exclusion Criteria:

The exclusion criteria include, but are not limited to, the following:

1. Patients who, during their participation in a previous dupilumab clinical trial,
developed a serious adverse event (SAE) deemed related to dupilumab*, which in the
opinion of the investigator or of the medical monitor could indicate that continued
treatment with dupilumab may present an unreasonable risk for the patient.

2. Patients who, during their participation in a previous dupilumab clinical trial,
developed an AE that was deemed related to dupilumab* and led to study treatment
discontinuation, which in the opinion of the investigator or of the medical monitor
could indicate that continued treatment with dupilumab may present an unreasonable
risk for the patient.

3. Conditions in the previous dupilumab study consistent with protocol-defined criteria
for permanent study drug discontinuation, if deemed related to dupilumab* or led to
investigator - or sponsor-initiated withdrawal of patient from the study (eg,
non-compliance, inability to complete study assessments, etc.).

*Note for exclusion criteria # 1, 2, and 3: In studies that are still blinded,
conditions deemed related to the study treatment will be considered related to
dupilumab.

4. Treatment with an investigational drug, other than dupilumab, within 8 weeks or
within 5 half-lives (if known), whichever is longer, before the baseline visit

5. Pregnant or breastfeeding women, or planning to become pregnant or breastfeed during
the patient's participation in this study