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: 1. Doxepin, hydroxyzine, or diphenhydramine use within 1 week prior to Day 1. 2. Use of topical product containing urea or any antihistamine within 1 week prior to Day 1. 3. Use of systemic antibiotic within 2 weeks, or topical antibiotics within 1 week, prior to Day 1. 4. 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. 5. Psoralen-UV-A or UV-B phototherapy (including tanning beds) or excimer laser within 4 weeks prior to Day 6. 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.