Evaluate the efficacy of induced pluripotent stem cell-derived exosomes (iPSC-Exos) for the treatment of stable vitiligo

This study aims to evaluate the efficacy and safety of iPSC-Exos in the treatment of localized stable vitiligo. iPSC-Exos have been found to possess the ability to promote cell survival, proliferation, and repair, potentially improving skin pigmentation in vitiligo patients by modulating the survival and function of melanocytes.

This study will consist of 2 parts, with part 1 being a dose-escalation study and part 2 being an expanded safety study based on part 1 findings.

A traditional 3+3 dose escalation design will be implemented in part 1. Cohort 1: receive 1×10^8 particles per time; cohort 2: 3×10^8 particles per time and cohort 3: 9×10^8 particles per time.

In part 2, 20 subjects will be randomized in a 1:1 ratio [exosome (n=10) or exosome placebo (n=10)]. The dose level will be determined by Data Safety Monitoring Board based on part 1.

Inclusion Criteria:

1. Agree to follow the trial treatment protocol and visit schedule, voluntarily enroll in the study, and provide written informed consent;
2. Aged 18-60 years old (inclusive of 18 and 60 years);
3. Clinically diagnosed with stable localized vitiligo (in accordance with the 2021 Consensus on the Diagnosis and Treatment of Vitiligo); Stability criteria: ① A score of 0 on the Vitiligo Disease Activity (VIDA) scale; ② Clinical characteristics: white patches appear porcelain white, with clear or pigmented edges; ③ No Koebner phenomenon (for ≥1 year); ④ Wood's lamp examination: lesions appear white with clear boundaries, and the area under Wood's light is ≤ visual estimation area, indicating stability. Skin CT and dermatoscopy images may also be referenced for diagnostic assistance. Localization criteria: Refers to single lesions, with an area classified as grade 1 (lesion area <1% of total body surface area), where it is not yet possible to determine whether the presentation is segmental or non-segmental at the time of consultation.
4. Lesions have been stable for more than 6 months, with a number of foci ≥3, ensuring that at least 2 lesions have an area >2cm²;
5. Have no plans for conception during the study period and for 3 months after the last administration, and can adopt effective contraceptive measures;
6. Agree to suspend any other anti-vitiligo treatments outside of the study protocol during participation in this clinical research (excluding cosmetic cover-ups).

Exclusion Criteria:

1. Individuals with clinically significant multiple or severe drug allergies, or those who have had serious allergic reactions to treatments, or where the investigator anticipates that the participant may be allergic to the study medication or any of its components;
2. Participants diagnosed with progressive vitiligo or moderate-to-severe stable vitiligo;
3. Total depigmented area ≥1% of body surface area (BSA);
4. Those who have received other treatments for vitiligo within the recent past (within 3 months), such as corticosteroids, JAK inhibitors, topical herbal medicines, depigmentation therapy, melanocyte-keratinocyte transplant surgery, phototherapy, etc.;
5. Participants with other active pigmented skin diseases during the screening period, such as pityriasis alba, senile leukoderma, chemical/drug-induced vitiligo, hyperpigmentation due to malignancy, post-inflammatory hyperpigmentation, ataxia telangiectasia, tuberous sclerosis, melasma, congenital hypopigmentation disorders, etc.;
6. Evidence of active inflammatory skin disease or skin condition during the screening period, such as atopic dermatitis, psoriasis, discoid lupus, leprosy, syphilis, seborrheic dermatitis, etc., which the investigator assesses might interfere with the evaluation of response and safety regarding vitiligo treatment;
7. Pregnant or breastfeeding women;
8. Participants with a history or current diagnosis of other autoimmune diseases and major illnesses: tuberculosis, AIDS, malignancies, cardiovascular and cerebrovascular diseases, liver and kidney diseases, etc.;
9. Individuals with a history of substance or alcohol abuse or those suffering from mental health conditions;
10. Abnormal blood test results that the investigator judges could affect the assessment of efficacy and safety of the participant or the trial outcomes;
11. Any other circumstances where the investigator believes that the participant's compliance may be affected or they are unsuitable to participate in this study.

The study will not share individual participant data to other researchers.