A multicenter clinical study to evaluate the safety, PK characteristics, immunogenicity characteristics, and PD characteristics of IBI3013 in healthy trial participants and active non-segmental vitiligo trial participants and severe alopecia areata trial participants. The study is divided into 2 parts, with Part 1 involving healthy trial participants lasting up to 24 weeks, and Part 2 involving active non-segmental vitiligo trial participants and severe alopecia areata trial participants lasting up to 48 weeks.

Inclusion criteria

1. Part 1 - Healthy trial participants: Understand and voluntarily sign the informed consent form;
2. Part 1 - Healthy trial participants: Age between 18-45 years (inclusive), male or female;
3. Part 1 - Healthy trial participants: Weight between 50-120 kg (inclusive), and BMI between 17.0-28.0 kg/m2 (inclusive);
4. Part 2 - Active non-segmental vitiligo trial participants: 18-65 years old (inclusive), male;
5. Part 2 - Active non-segmental vitiligo trial participants: Diagnosed with non-segmental vitiligo for ≥3 months and <2 years;
6. Part 2 - Active non-segmental vitiligo trial participants: Total affected BSA 3-50%, and facial affected BSA ≥ 0.5%; T-VASI 3-50 (inclusive), and F-VASI ≥0.5; ≥1 active lesion;
7. Part 2 - : Male participants of reproductive potential agree to use highly effective contraception and avoid sperm donation for 6 months after the last dose.
8. Part 2 - Severe alopecia areata trial participants: 18-60 years old (inclusive), male;
9. Part 2 - Severe alopecia areata trial participants: Meet the following severe alopecia areata criteria: a) SALT ≥50% (i.e., AA-IGA 3-4 grade) b) No spontaneous remission in the past 6 months (spontaneous remission defined as SALT reduction by ?10 points) c) Current duration of severe alopecia areata ≥6 months and <4 years;
10. All participants: Participants of reproductive potential agree to use highly effective contraception and avoid sperm or egg donation for 6 months after the last dose.

Exclusion criteria

1. All participants: Those who are allergic to any component of IBI3013;
2. All participants: Those who cannot tolerate subcutaneous injection;
3. All participants: History of live or attenuated live vaccine within 30 days prior to randomization, or expected to receive such vaccines during the study period until 3 months after the last dose of the investigational drug;
4. All participants: Donated blood or lost ≥400 mL of blood within 3 months before screening;
5. All participants: History of herpes zoster or disseminated herpes simplex (single episode), or recurrent (more than one episode) localized herpes zoster;
6. All participants: Known history of active tuberculosis or clinical manifestations suggestive of tuberculosis, or positive interferon-gamma release assay unsuitable for participation;
7. All participants: Abnormal vital signs, serum virology tests, laboratory tests, ECG, or other examinations with clinical significance, and deemed unsuitable for the study by the investigator;
8. All participants: Received specific treatment within the time frame specified in the protocol, or participated in other investigational drug studies within the specified time;
9. All participants: History of drug abuse, drug dependence, or positive drug screening results during the screening period within 12 months;
10. All participants: Pregnant or lactating women;
11. All participants: Coexisting diseases at screening or previously, deemed unsuitable for clinical trials;
12. Active non-segmental vitiligo/Severe alopecia areata trial participants: Previous or coexisting diseases, which may affect the efficacy or safety evaluation of the study as assessed by the investigator;
13. Active non-segmental vitiligo trial participants: Coexisting segmental, undetermined type, or mixed-type vitiligo, or other skin pigmentation disorders, or other skin-related abnormalities that may affect the assessment of the study;
14. Severe alopecia areata trial participants: Currently diagnosed with primary diffuse AA or ophiasis AA; or other types of hair loss that may interfere with AA evaluation;
15. Severe alopecia areata trial participants: Previously received oral JAK inhibitors with poor response; 16. Severe alopecia areata trial participants: Acute myocardial infarction, unstable ischemic heart disease, stroke, chronic heart failure (NYHA class III/IV) within 12 weeks prior to screening; or previous history of deep vein thrombosis, or high risk of deep vein thrombosis as assessed by the investigator; or severe neuropsychiatric disorder, deemed unsuitable for the study by the investigator.