This is a multicenter, randomized, double-blind, placebo-controlled, parallel design study of BLU-5937 for the treatment of chronic pruritus in adult subjects with atopic dermatitis (AD).

The study will consist of a 37-day Screening period (including a 7-day Run-In period), a 4-week Treatment period followed by a Follow-Up visit approximately 2 weeks after the last dose of study drug.

Inclusion Criteria:

• Willing to participate and is capable of giving informed consent
• Clinically confirmed diagnosis of active AD with at least a 6-month history of AD
• Chronic pruritus related to AD for at least 3 months
• Moderate to severe itch associated with mild to moderate AD
• Female of childbearing potential must agree to use a highly effective contraceptive method during the study and until at least 4 weeks after the last study drug administration

Exclusion Criteria:

• History of skin disease or presence of skin condition that would interfere with the study assessments
• Clearly defined etiology for pruritus other than AD, including but not limited to: urticaria, psoriasis, or other non-atopic dermatologic conditions, hepatic or renal disease, psychogenic pruritus, drug reaction, uncontrolled hyperthyroidism, and infection
• Presence of any acute skin condition other than AD which may risk inducing a pruritus flare/worsening during the course of the study, including but not limited to: impetigo, active herpes simplex infection, or allergic contact dermatitis
• Subject is >65 years of age and has developed pruritus at age of ≥50 years
• History of cancer or lymphoproliferative disease within 5 years with the exception of successfully treated nonmetastatic cutaneous squamous cell or basal cell carcinoma and/or localized carcinoma in situ of the cervix
• Known history of, or active, parasitic infection, including skin parasites such as scabies within 12 months prior to Screening
• Known history of chronic infectious disease (e.g. hepatitis B, hepatitis C, or human immunodeficiency virus [HIV])
• Known history of clinically significant drug or alcohol abuse in the last year
• Previous participation in a BLU-5937 trial