This is a Phase Ia single-center, randomized, double-blind, placebo-controlled study to assess the safety, tolerability, Pharmacokinetic of GenSci142 in Chinese healthy women.

This is a Phase 1a trial including single ascending dose levels and will assess the safety and tolerability of GenSci142 and describe the incidence of adverse events (AEs) for participants randomized at a ratio of 4:1 to GenSci142 or placebo within each cohort. Participants will receive one single dose of study treatment.

Inclusion Criteria:

• Healthy women of childbearing potential aged 18-55 years (inclusive) at the time of signing the Informed Consent Form (ICF);
• Sexually active and willing to undergo vaginal administration of the study product；participants must agree to avoid the use of other intravaginal products (e.g., contraception ointments, gels, foams, sponges, lubricants, irrigation solutions, tampons, etc.) throughout the trial;
• During the screening period, there are no clinically significant abnormalities in medical history, vital signs, physical examination, gynecological examination, laboratory test (hematology, routine urinalysis, clinical chemistry, coagulation function, vaginal microbiome test) and 12-lead ECG, or any out-of-range laboratory values or other findings must be assessed by the investigator as not clinically significant;

Exclusion Criteria:

• Those experiencing stinging or burning sensation, hemorrhage, pruritus, erythema, edema, or increased discharge due to previous or current use of vaginal preparations, or those with any factors that possibly have an impact on evaluation of administration site irritation, or those with other factors that may have an impact on vaginal administration, such as genital malformation;
• Serious infections, chronic infections, opportunistic infections, etc. within 3 months prior to screening, and infections treated with systemic antimicrobial drugs (including but not limited to viruses, bacteria, fungi, and parasitic infections) within 4 weeks prior to randomization;
• Surgical history: a. vaginal, pelvic or cervical surgery within 90 days prior to screening or planning to undergo surgery during the study; b. hysterectomy; c. other major surgery within 30 days prior to screening or planning to undergo other surgeries during the study;