This is a multicenter, open-label study designed to determine the long-term safety of ASC40 (Denifanstat) tablets in patients with moderate to severe acne vulgaris enrolled in the ASC40-303 Phase III study. All subjects are eligible for study eligibility screening after enrollment in ASC40-303 Phase III study, and all eligible subjects with moderate to severe acne vulgaris will receive ASC40 (Denifanstat) tablets after signing informed consent. The investigational drug will be administered orally once daily (QD) for up to 40 weeks. There will be a total of 7 visits for screening and follow-up. The tests required by the program included routine blood tests, blood biochemistry, lipid profile, pregnancy test and urine routine, etc.

Inclusion Criteria:

• Participants who have successfully completed a 12-week Phase III study of ASC40-303;
• Have fully understood this research and voluntarily signed the informed consent;
• The fertile male and female subjects of reproductive age agreed to use effective contraception from the time they signed the informed consent until 3 months after the final administration of the investigationa drug;
• Subjects are willing and able to complete the study, understand and comply with the study requirements, comply with the study requirements restrictions and related education, use the investigational drug as prescribed by the physician, and follow up according to the study schedule.

Exclusion Criteria:

• Discontinue participation in the ASC40-303 Phase III study for any reason;
• Are receiving/planning to receive any systemic acne medications, systemic retinoids, systemic corticosteroids, or any androgen/antiandrogen therapy (e.g., testosterone, spironolactone);
• Pregnant, nursing, or planning a pregnancy during the study period;
• Have major complications (including clinically significant abnormalities in clinical laboratory tests), mental disorders, or other factors deemed unsuitable for study participation by the investigator.