A Study to Assess the Efficacy and Safety of PG-011 Gel in Adolescents and Adults With Atopic Dermatitis

This is a Multicenter, Randomized, Double-blind, Placebo-controlled seamless and adaptive-designed phase IIb/III study to Assess the Efficacy and Safety of topical use of PG-011 Gel in adolescents and Adults With Atopic Dermatitis. It consists of phase IIb and phase III parts, phase IIb is a dose-ranging part and has been done, and phase III is a pivotal study part which is registered this time.

The goal of this phase III clinical trial is to learn if PG-011gel works to treat mild to moderate Atopic Dermatitis in adolescents and adults by topical use. It will also learn about the safety of PG-011gel. Investigators will compare PG-011gel to a placebo (a look-alike substance that contains no drug) to see if PG-011gel works to treat mild to moderate Atopic Dermatitis.

Participants will:

* Use PG-011gel or a placebo twice daily for initial 8 weeks, and followed by using PG-011 gel for all of the participants till 52-week.
* Visit the clinic at weeks 1, 2, 4 and 8 for checkups and tests, and followed by visiting the clinic every 4 weeks till 52-week.
* Keep a diary of their symptoms.

This is a randomized, double-blind, placebo-controlled, multicenter clinical trial in adolescent and adult participants aged from 12 to 75 years old (including threshold) with mild to moderate Atopic Dermatitis. Approximately 472 participants will be randomized 3:1 to PG-011 gel 3% BID, or placebo gel. In addition, approximately 10% of the overall study population will consist of adolescents. Participants with AD involvement of 3% to 20% BSA and IGA score of 2 to 3 will receive blinded study treatment for 8 weeks followed by an open-label treatment for 44 weeks, at last the safety follow-up for 2 weeks.

The study is to evaluate the efficacy and long-term safety of PG-011 gel 3% in the treatment of mild to moderate Atopic Dermatitis and the PK characteristics by sparse sampling.

Eligibility Criteria:
Inclusion Criteria:

1. 12 years old≤ age ≤ 75 years old (including threshold), male or female.
2. Participants diagnosed of atopic dermatitis (AD) as defined by the Williams diagnostic criteria.
3. AD/eczema duration of at least 1 year for adults and 6 months for adolescents.
4. IGA score of 2 (mild) or 3 (moderate) at the screening day and day 1.
5. %BSA (excluding the scalp) with AD involvement of at least 10% and up to 20%.
6. Willingness to avoid pregnancy or fathering children based on the criteria as outlined in the protocol.

Exclusion Criteria:

1. Participant has unstable course of AD (spontaneously improving or rapidly deteriorating).
2. Immunocompromised (e.g. lymphoma, acquired immunodeficiency syndrome, Wiskott-Aldrich syndrome).
3. Any other concomitant skin disorder(e.g. generalized erythroderma, Netherton syndrome, acne, psoriasis, urticaria, pigmentation or extensive scarring）, in the opinion of investigator, may interfere with the evaluation of AD lesions or compromise participant safety.
4. Participant with chronic or acute infection needs to be treated with systemic antibiotics, antiviral drugs, antiparasitic drugs, anti-antigenic animal drugs or antifungal drugs within 2 weeks before randomization.
5. Participant with active acute/chronic bacterial, fungal or viral skin infections (such as herpes simplex, herpes zoster, chickenpox, etc.) before randomization, including but not limited to clinically significant secondary infections of AD or other infections associated with AD lesions.
6. Participant has human immunodeficiency virus (HIV) infection, active hepatitis C virus (HCV) infection (anti-HCV positive), active hepatitis B virus (HBV) infection (HBV-DNA \&gt; 2000IU/ml) or Treponema pallidum antibody positive and showing active.
7. Clinically significant or uncontrolled cardiovascular disease (including but not limited to unstable angina, acute myocardial infarction, heart failure, arrhythmia requiring treatment or uncontrolled hypertension).
8. Participant has serious diseases or complications of the central nervous system, respiratory system, liver, kidney, gastrointestinal tract, urinary system, endocrine system or immune system, blood system, etc., and in the opinion of the investigator, may affect the judgment of efficacy and safety .
9. Participant has mental illness such as anxiety disorder, depression, or other conditions that affect the compliance and may interfere with the implementation of clinical research.
10. Participant has a history of malignant tumors before randomization.
11. Participant has severe and uncontrolled disease that may affect safety, trial compliance, affect the evaluation of endpoints, and require the use of drugs that are not allowed in the protocol.
12. Female participant who is lactating or pregnant at the time of screening.
13. Any situation affects the safety and efficacy evaluation of the study drug judged by investigator.
14. Any other condition that, in the opinion of the investigator or sponsor, makes the subject unsuitable for participation in the study.