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

All participants will sign an informed consent form and undergo screening (within 28 days prior to Day 1). During the screening period, all treatments for Atopic Dermatitis (AD) (also known as eczema) and/or itch will be stopped to allow for wash out, as applicable and according to eligibility requirements. Consistent daily or twice daily use of a non-prescription emollient is required at least 7 days prior to Day 1 and throughout the trial until the follow-up (Week 8). No other products, including, but not limited to, topical corticosteroids, calcineurin inhibitors, biologics, or Janus Kinase (JAK) inhibitors (topical or oral) may be used during the trial.

Eligible participants will be randomized in a 1:1:1:1 ratio to receive ASN008 gel 1.25 percent, ASN008 gel 2.5 percent, ASN008 gel 5.0 percent, or matching vehicle twice daily for 4 weeks (28 days), followed by a 4-week (28-day) follow-up period. The first dose of study treatment will be applied on Day 1 and the last dose will be applied on the morning of Day 28.

Participants will be required to participate in 8 scheduled visits: Screening; Randomization (remote visit); Day 1; Week 1 (Day 8); Week 2 (Day 15); Week 3 (Day 22); Week 4 (Day 28); and Week 8 (Day 56)/early termination (ET).

The trial duration per participant is up to 12 weeks (84 days): including up to 4 weeks (28 days) for the screening period, 4 weeks (28 days) for the treatment period, and up to 4 weeks (28 days) for the follow-up period.

A participant is considered to have reached the end of the trial when they have completed their Day 56 (Week 8) or ET visit. The trial will be considered complete when the last participant has completed their last trial visit.

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.