Clinical Trials

Inclusion Criteria:

• Male and female adults aged ≥18 years (at the screening visit) with capacity to consent who are initiating treatment with either dupilumab or a JAKi.

• Moderate-to-severe AD (EASI≥16 or IGA ≥3).

• AD duration of at least 3 months.

• Systemic treatment naïve or no systemic treatments in the preceding 3 months.

• No topical treatment use in the preceding 2 weeks.

• At least 1 target lesion that measures at least 2 cm² at first visit. The target lesion must be representative of the participant's disease state but not located on the hands, feet, genitalia, face, scalp, or intertriginous areas.

Exclusion Criteria:

• Unstable history of AD (spontaneously improving or rapidly deteriorating) as determined by the investigator over the previous 4 weeks before baseline/visit 0.

• Disease history concerns, i.e., lymphoma, immunodeficiency, chronic infections such as HIV, hepatitis, or tuberculosis, dialysis, and/or history of skin cancer within 5 years.

• Chronic or acute infection requiring treatment with systemic antibiotics, antivirals, antiparasitics, antiprotozoals, or antifungals within 2 weeks before the baseline/visit 0.

• Active acute bacterial, fungal, or viral skin infection (e.g., herpes simplex, herpes zoster, chicken pox, clinically infected AD, impetigo) within 1 week before the baseline/visit 0.

• Insufficient area of uninvolved (control) skin.

• Relative contraindications to skin biopsy (e.g., serum platelets <10; allergy to lidocaine)

• AD exclusive to areas of the hands, feet, face, scalp, intertriginous areas, or genitalia.

• Inability to proceed with follw-up biopsy after 16-20 weeks of treatment.

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 10/03/2025. Questions regarding updates should be directed to the study team contact.