A Study to Evaluate the Anti-pruritic Effectiveness of ASN008 in Adults With Mild to Moderate Atopic Dermatitis

Inclusion Criteria: Male or female participants, 18 years or older, at the time of informed consent. Diagnosis of mild to moderate AD for at least 12 months with no significant disease flares for at least 4 weeks before Screening (based upon medical chart, treating physician, or participant report with documented clinical confirmation by the Investigator) Validated Investigator Global Assessment (vIGA) score of 2 or 3 at Day 1. Body surface area (BSA) affected by AD ≤20% at Day 1. Peak Pruritus NRS ≥7 at Day 1. Body mass index (BMI) ≤40 kg/m2 at Screening. Willingness to avoid pregnancy or fathering children. Participant is willing to participate for the duration of the trial, comply with all trial procedures, and is capable of giving informed consent. Exclusion Criteria: Any female who is breastfeeding, pregnant, or who is planning to become pregnant during the trial. Active infection requiring treatment, including skin infections (including clinically infected AD). History of skin disease or presence of a skin condition that, in the opinion of the Investigator, would interfere with trial assessments. Any clinically significant medical or psychiatric condition or physical/laboratory/ECG/vital signs abnormality that would, in the opinion of the Investigator, put the participant at undue risk or interfere with interpretation of trial results. Use of any of the following treatments within the indicated washout period before Day 1: Doxepin, hydroxyzine, or diphenhydramine use within 1 week prior to Day 1. Use of topical product containing urea or any antihistamine within 1 week prior to Day 1. Use of systemic antibiotic within 2 weeks, or topical antibiotics within 1 week, prior to Day 1. Atopic dermatitis topical medication use within 2 weeks prior to Day 1, including, but not limited to, topical corticosteroids, crisaborole and any other topical phosphodiesterase-4 inhibitor, calcineurin inhibitors, JAK inhibitors, tars, bleach, antimicrobials, medical devices, and bleach or oatmeal baths. Psoralen-UV-A or UV-B phototherapy (including tanning beds) or excimer laser within 4 weeks prior to Day Systemic medication use including biologics that could affect AD less than 6 weeks prior to Day 1 (e.g., retinoids, calcineurin inhibitors, methotrexate, cyclosporine, hydroxycarbamide [hydroxyurea], azathioprine, oral/injectable corticosteroids), biologics and JAK inhibitors. Known hypersensitivity to ASN008 or its excipients.