Study of D-2570 in Subjects With Non-Segmental Vitiligo

This study tests D-2570, an investigational drug, in people with non-segmental vitiligo to check its safety and effect on skin discoloration. Eligible participants will take D-2570, or a placebo, once daily for 24 weeks in a double-blind setting. Most will then continue into a 24-week extension phase All participants will have a 4-week safety follow-up after treatment ends, with regular check-ups and blood tests throughout the study.

Inclusion Criteria: * Voluntarily signs informed consent and complies with study procedures. * Age 18-65 years, male or female. * Clinical diagnosis of non-segmental vitiligo at screening. * F-VASI ≥0.25 and T-VASI ≥5 at screening and baseline, with either active or stable vitiligo. * Women of childbearing potential have negative pregnancy tests at screening and baseline. All eligible subjects agree to effective contraception from consent through 30 days after last study drug dose. Exclusion Criteria: * \- Segmental, mixed vitiligo or other concurrent pigmentary/active skin disorders interfering with study assessment. * Over 33% facial or total vitiligo lesions with leukotrichia. * Pregnant or breastfeeding females. * Active, latent or inadequately treated tuberculosis infection. * Positive HIV, active HBV/HCV infection, or untreated syphilis. * Current or history of severe herpes infection. * Severe systemic infection requiring recent inpatient, intravenous or oral anti-infective treatment. * Congenital or acquired immune deficiency, opportunistic infection history, or conditions requiring systemic immunosuppression during the study. * Uncontrolled thyroid disease, severe cardiovascular/cerebrovascular disease or other unstable severe systemic disorders. * Severe psychiatric disease, suicidal ideation, or alcohol/drug abuse within 6 months. * Malignancy history within 5 years (excluding cured non-melanoma skin cancer and cervical intraepithelial neoplasia). * Gastrointestinal disease affecting drug absorption or major surgery within 8 weeks prior to dosing. * Clinically significant abnormal lab results: elevated liver/renal indices, decreased hemoglobin, WBC, platelet, lymphocyte or neutrophil counts. * History of severe drug hypersensitivity or drug-related toxicity. * Any condition that may impair protocol compliance or study participation per investigator judgment.