Study to Evaluate ASN008 Topical Gel (TG)

This is a two part, randomized, blinded, vehicle-controlled study to determine a safe and tolerable dose of ASN008 TG. Part A will asses a single ascending dose of ASN008 TG in cohorts of healthy volunteers, while Part B will assess multiple ascending doses of TG, to be determined (TBD) based on Part A safety and tolerability, in patients with mild-to-moderate dermatitis. Results from Part A and B will characterize safety, tolerability and pharmacokinetics. Part B patients will be assessed for changes in pruritus based on a numerical rating scale (NRS) of pruritus at baseline and on Day 15.

Inclusion criteria

Part A - Healthy Volunteers:

• Written informed consent obtained prior to any required study-related procedure
• Healthy female or male subject aged 18 to 65
• Willing to use medically effective methods of birth control
• Females of reproductive potential must have a negative serum pregnancy test at screening and negative serum or urine pregnancy test prior to first study drug application on Day 1
• Non-smoker (no nicotine products for at least 6 months prior to screening)
• BMI ≥18.5 kg/m2 and ≤32.0 kg/m2 with minimum weight of 60 kg

Part B- Subjects with AD:

• Written informed consent obtained prior to any required study-related procedure
• Confirmed diagnosis of active atopic dermatitis (AD)
• History of AD for at least 6 months prior to Day 1 with an investigator global assessment ≥3 and body surface area covered with 1-10% AD
• Pruritus score (NRS)≥ 5 at screening and NRS ≥7 on Day 1

Exclusion criteria

Both Part A and Part B:

• Pregnant or breast-feeding women
• Skin disease that may interfere with study assessments
• Febrile illness within 6 days prior to Day 1, history of cancer within 5 years of Day 1, major surgery within 8 weeks prior to Day1, known immunodeficiencies, positive for hepatitis B or C or HIV infection
• Significant medical/surgical history or condition or current physical/laboratory/ECG/ vitals signs abnormality that might compromise the subject
• Corrected QT duration ≥450 milliseconds or other significant ECG abnormality
• Received marketed or investigational biological agent within 12 weeks prior to Day 1 or JAK inhibitor or nonbiological product or device within 4 weeks of Day 1 or within 8 weeks of Day 1 if investigational product used or any drug/ substance that is a strong inhibitor or inducer of CYP3A4 or CYP2D6
• Suspected hypersensitivity/allergy to lidocaine
• Significant drug or alcohol abuse or mental illness in 2 years prior to Day 1

Part A Only- Healthy Volunteers:

-Used medications or skin emollients within 2 weeks prior to Day 1 unless approved by investigator and sponsor

Part B Only - Subjects with AD:

• Has infected atopic dermatitis
• Used dupilumab 12 weeks prior to Day 1
• Used doxepin, hydroxyzine or diphenhydramine, urea containing topical products within 1 week prior to Day 1
• Used systemic antibiotics or topical medicated treatment or other systemic treatments that could affect AD 2 weeks prior to Day 1
• Received any UV-B phototherapy, excimer laser treatment or psoralen-UV-A treatment within 4 weeks prior to Day 1