Clinical Trial Finder

Inclusion Criteria for Parts A-C:

• - Males and females aged 18-45 (inclusive), - Weight: ≥ 50 kg for males and ≥ 45 kg for females, body mass index (BMI): 18.0-30.0 kg/m2 (inclusive), Inclusion Criteria for Part D: - Female or male participants between the ages of 18 to 75 years of age.

• - Chronic AD diagnosed by the criteria of Hannifin and Rajka that has been present for at least 6 Months before the Screening Visit.

• - At screening and baseline: EASI score ≥ 16, vIGA-AD™ score ≥ 3, and BSA affected by AD ≥ 10%; - The weekly mean score of PP NRS ≥ 4 prior to the first administration (with assessment results for at least 4 days during the week before the first administration [D-7 to D-1]); - As judged by the investigator, within 6 months prior to screening, the patient had an inadequate response to topical medication therapy.

General

Exclusion Criteria:

• - Participants with diseases that should be excluded as judged by the investigator at screening, including but not limited to the nervous system, psychiatric system, cardiovascular system, blood and lymphatic system, immune system, respiratory system, digestive system, urinary system, metabolic and skeletal system disorders, - The 12-lead ECG at screening shows QTcF (QT corrected using Fridericia's formula) > 450 ms.

If QTcF is > 450 ms, the 12-lead ECG should be repeated 2 more times (at least 3 min apart), and the mean of the 3 measurements will be used to determine whether the participant meets the inclusion criteria,

• - Participants who smoke more than 5 cigarettes per day on average within 6 months before screening or are currently using e-cigarettes, - Participants who consume more than 14 units of alcohol per week (1 unit = 360 mL of beer, 45 mL of 40% spirits, or 150 mL of wine) within 6 months before screening or have a positive breath alcohol test at screening, - Participants who have donated more than 400 mL of blood within 3 months or more than 200 mL of blood within 4 weeks before screening, or plan to donate blood during the study, - Participants who have received any strong inhibitor or inducer of CYP3A4 within 4 weeks before screening, - Participants who have received any prescription drugs, OTC drugs, traditional medicines, and dietary supplements within 2 weeks before the first dose or 5 half-lives (whichever is longer).

Note: Other protocol defined Inclusion/Exclusion criteria may apply.

Arms

Experimental: Single ascending dose cohorts in healthy participants

Healthy volunteer subject cohorts randomized 6:2 receiving a single dose of QLS12010 or placebo. The starting dose will be 25 mg of QLS12010 or placebo.

Experimental: Multiple ascending dose cohorts in healthy subjects

Healthy volunteer subject cohorts randomized 8:2 to receive QLS12010 or placebo QD for 14 continuous days. The starting dose of QLS12010 or placebo is based on upcoming data from SAD part.

Experimental: Food Effect Cohort in healthy subjects

Part C is a two-cycle, crossover study under fasting and fed (high-fat meal) conditions. In Cycle 1, 12 healthy adult participants will be randomly divided into two groups on D-1, with 6 participants in each group receiving a single oral dose of QLS12010 Capsules under fasting or fed conditions, respectively. After completing washout, they will receive crossover administration for the Cycle 2 study.

Experimental: Early Efficacy in patients with AD

Part D of the study plans to enroll 12 adults with moderate to severe atopic dermatitis (AD). Eligible subjects (after screening) will be sequentially assigned to two dose groups (Dose 1 and Dose 2) in the order of their enrollment. Enrollment of Dose 2 may commence only after Dose 1 has completed enrollment of 6 subjects.

Interventions

Drug: - QLS12010

QLS12010 oral capsule(s)

Drug: - Placebo

Matching placebo oral capsule(s)