The purpose of this study is to assess the efficacy and safety of barzolvolimab in adults with Atopic Dermatitis

This is a multicenter, randomized, double-blind, parallel group, placebo controlled phase 2 study to assess the efficacy and safety of barzolvolimab (CDX-0159) in adult participants with Atopic Dermatitis.

There is a screening period of up to 28 days, a 16-week double-blind, placebo-controlled treatment period, a 16-week double-blind, active treatment period, and a 16-week follow-up period. On Day 1, participants will be randomly assigned on a 1:1:1 ratio to receive barzolvolimab (CDX-0159) by subcutaneous injections of 150 mg every 4 weeks (Q4W) after an initial loading dose of 450 mg [Arm 1], 300 mg Q4W after an initial loading dose of 450 mg [Arm 2], or placebo Q4W [Arm 3]. At Week 16, participants on placebo will be re-randomized on a 1:1 ratio to receive barzolvolimab by subcutaneous injections of 150 mg every 4 weeks (Q4W) after an initial loading dose of 450 mg, 300 mg Q4W after an initial loading dose of 450 mg. Participants on Arms 1 and 2 will undergo a mock re-randomization at Week 16 to maintain the blind.

Inclusion Criteria:

1. Male or female ≥ 18 years of age

2. Diagnosis of chronic atopic dermatitis (AD) for at least 1 year

3. Onset of symptoms at least 1 year prior and current symptoms consistent with moderate to severe AD as defined by:

   1. EASI ≥ 12 at Visit 1 and EASI ≥ 16 at Visit 2
   2. Body Surface Area of Involvement (BSA) ≥ 10% at Visit 1 and Visit 2
   3. IGA score ≥ 3 at Visit 1 and Visit 2
   4. Severe itch, defined by weekly average of daily PP-NRS score of ≥ 5, during the 7 days prior to treatment

4. Documented history of inadequate response to treatment with topical medications or for whom topical medications are otherwise medically inadvisable.

5. Willing and able to complete a daily symptom electronic diary for the duration of the study and adhere to the study visit schedule.

Exclusion Criteria:

1. Any other active pruritic skin diseases that would confound AD assessments based on the Investigator's clinical judgment.
2. Phototherapy with ultraviolet (UV) A or UVB within 4 weeks of Visit 1.
3. Planned or anticipated use of any prohibited medications at any time during the study.
4. Prior receipt of barzolvolimab or other anti-KIT therapy. There are additional criteria that your study doctor will review with you to confirm you are eligible for the study.