An Early-stage Clinical Trial to Evaluate the Safety, Absorption, and Disposition of YR001 Ointment Following Topical Application on the Skin of Healthy Chinese Subjects

The goal of this clinical trial is to evaluate the safety, local tolerability, and pharmacokinetic (PK) profile of YR001 Topical Ointment in healthy Chinese participants. This is a first-in-China, Phase I study designed to assess the drug's systemic absorption and disposition following single and multiple topical applications. The main questions it aims to answer are: What is the safety and local tolerability profile of YR001 Topical Ointment after single-dose and multiple-dose administration in healthy Chinese participants? What are the pharmacokinetic characteristics (e.g., plasma drug concentrations) of YR001 Topical Ointment after single and multiple topical applications? Researchers will compare participants receiving YR001 Topical Ointment with participants receiving vehicle (placebo) to determine whether the safety profile and local tolerability of YR001 are comparable to placebo. Participants will: Receive topical application of either YR001 Topical Ointment or matching placebo (vehicle) on approximately 10% or 20% of their body surface area, depending on the assigned group Undergo serial blood sampling for pharmacokinetic assessments at specified time points before and after drug administration Complete safety evaluations including physical examinations, vital signs, laboratory tests (hematology, biochemistry, coagulation, thyroid function, urinalysis), 12-lead ECGs, and local tolerability assessments at the application site Remain in the clinical unit for specified periods during the dosing and follow-up phases, with total study participation duration up to approximately 30 days per participant