A Study to Confirm the Efficacy and Safety of Different Dupilumab Dose Regimens in Adults With Atopic Dermatitis (AD)

Key Inclusion Criteria:

1. Must have completed the treatment phase in 1 of the two 16-week initial treatmentstudies (R668-AD-1334 or R668-AD-1416).

2. Must have achieved at least 1 of the following 2 treatment success criteria: Investigator Global Assessment (IGA) = 0 or 1 (clear or almost clear) at week 16 OREczema Area and Severity Index >= 75% (EASI-75) (at least 75% reduction in EASI scorefrom baseline to week 16)

3. Must be willing and able to comply with clinic visits and study-related procedures

4. Must provide signed informed consent

5. Must be able to understand and complete study-related questionnaires

Key Exclusion Criteria:

1. Receipt of rescue medication for AD in the initial treatment study

2. Any conditions that require permanent discontinuation of study treatment in eitherinitial treatment study

3. Planned or anticipated major surgical procedure during the participants'sparticipation in this study

4. Pregnant or breastfeeding women, or women planning to become pregnant or breastfeedduring this study

5. Women unwilling to use adequate birth control, if of reproductive potential* andsexually active. Adequate birth control is defined as agreement to consistentlypractice an effective and accepted method of contraception, whenever engaging inheterosexual intercourse, throughout the duration of the study and for 120 days afterlast dose of study drug. These include hormonal contraceptives, intrauterine device,or double barrier contraception (e.g, condom + diaphragm), or a male partner withdocumented vasectomy. Additional requirements for acceptable contraception may applyin certain countries, based on local regulations. Investigators in these countrieswill be notified accordingly in a protocol clarification letter.

(*For females, menopause is defined as at least 12 consecutive months without menses; if inquestion, a follicle stimulating hormone level of >= 25 milli units per milliliter (mU/mL)must be documented. Hysterectomy, bilateral oophorectomy, or bilateral tubal ligation mustbe documented, as applicable; if documented, women with these conditions are not requiredto use additional contraception).