This is a randomized, double-blind, placebo-controlled Phase Ib/II clinical trial of multiple subcutaneous injections of GR2301 in combination with phototherapy to evaluate the tolerability, safety, pharmacokinetics, and preliminary efficacy in trial participants with vitiligo. The trial will be conducted in two stages: a dose-escalation stage (Phase Ib) and an expansion cohort stage (Phase II).

Main Inclusion Criteria:

1. Meet the clinical diagnosis of non-segmental vitiligo at screening visit and baseline visit, and meet the following criteria: clinical diagnosis of non-segmental vitiligo for at least 3 months at screening visit; facial affected BSA ≥0.5% and total body affected BSA ≥3% at screening visit and baseline visit; F-VASI and T-VASI scores meet the criteria at screening visit and baseline visit.
2. Able to understand and comply with the requirements of the clinical protocol, voluntarily participate in the clinical trial, and provide signed written informed consent by the trial participant or their legally authorized representative.

Main Exclusion Criteria:

1. Vitiligo-related medical conditions and other dermatologic diseases/conditions.
2. Prior permanent tattooing or grafting within the vitiligo lesions.
3. Have absolute contraindications to phototherapy; or have relative contraindications to phototherapy (as comprehensively judged by the investigator).
4. Are unwilling or unable to comply with the permitted and prohibited concomitant medications/treatment specifications of this trial, and cannot meet the protocol-required washout period for medications/treatments prior to randomization.
5. Have a serious underlying disease that, in the investigator's opinion, may pose a safety risk to the trial participant if enrolled in the clinical trial.