The phase 1 study which includes the screening phase (up to 3 weeks) and treatment phase (12 weeks). After signing the informed consent, the inclusion and exclusion criteria will be confirmed preliminarily at screening visit and reconfirmed at Day 1 (baseline). At least 418 eligible subjects will be randomized in a 1:1 ratio to receive 6.5mg of intravaginal prasterone or placebo once-daily for 12 weeks.~The phase 2 study which includes the treatment phase (26 weeks). A total of 100 subjects who have completed Phase 1, not occur adverse event（AE） grade ≥3 or serious adverse event (SAE), or recover all AE grades ≤1, and voluntary to participate in Phase 2 study. After signing the ICF, the subject will receive 6.5mg of intravaginal for 26 weeks.
This study is a phase III which includes two treatment phases. The phase 1 study is a multi-center, randomized, double-blind, placebo- controlled, parallel group that provide primary efficacy and safety data.~The Phase 2 study is a single-arm, open-label conducted in a subset of subjects who completed the phase 1 study to provid additional long-term safety and efficacy.