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