FOSTER CITY, Calif., August 13, 2026
Sagimet Biosciences Inc. announced that the U.S. Food and Drug Administration (FDA) has cleared the company’s Investigational New Drug application and issued a “Study May Proceed” letter for its planned Phase 3 clinical trial of denifanstat in patients with moderate to severe acne. The regulatory milestone clears the path for Sagimet to initiate the U.S. Phase 3 study during the second half of 2026. Denifanstat is an investigational, oral once-daily fatty acid synthase (FASN) inhibitor designed to target metabolic pathways involved in acne development. The randomized, double-blind, placebo-controlled trial is expected to enroll approximately 800 patients aged 12 years and older, including approximately 450 adolescents between 12 and 17 years of age. Participants will receive either denifanstat 50 mg or placebo once daily for 12 weeks, followed by an optional 40-week open-label extension designed to evaluate long-term safety.
Phase 3 Trial Will Evaluate Multiple Acne Endpoints
The Phase 3 study has been designed to evaluate the efficacy and safety of denifanstat in moderate to severe acne using three co-primary endpoints at Week 12. These include treatment success based on a global assessment score, the absolute change in inflammatory skin lesion counts, and the absolute change in non-inflammatory skin lesion counts from baseline. Participants will be randomized in a 2:1 ratio to receive denifanstat or placebo during the initial 12-week treatment period. Patients completing the randomized period will have the opportunity to enter a 40-week open-label extension, allowing investigators to collect longer-term safety data. Sagimet expects the adolescent population to represent a substantial portion of the trial, reflecting the high prevalence of acne among younger patients. The company believes denifanstat’s differentiated mechanism could provide a new oral treatment approach for patients with moderate to severe disease who require ongoing management.
Denifanstat Targets Fatty Acid Synthase Pathway
Denifanstat is designed to inhibit fatty acid synthase (FASN), an enzyme involved in lipid synthesis and a metabolic pathway implicated in several diseases. Sagimet is developing FASN inhibition as a potential therapeutic strategy for conditions associated with abnormal production of the fatty acid palmitate. In acne, the company believes modulation of this metabolic pathway could address biological processes contributing to disease activity. Denifanstat has already generated clinical data in China through Sagimet’s licensing partner Ascletis BioScience Co. Ltd., where the treatment met primary and secondary endpoints in a 12-week randomized Phase 3 trial in moderate to severe acne vulgaris. According to Sagimet, denifanstat was generally well tolerated and improvements across measured efficacy endpoints were observed in a separate long-term open-label Phase 3 evaluation. However, previous results from China do not guarantee that the U.S. Phase 3 study will produce positive outcomes, making the upcoming trial an important test of denifanstat’s efficacy and safety in the U.S. population.
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FDA Clearance Positions Sagimet for Late-Stage Development
The FDA’s IND clearance represents a significant regulatory milestone for Sagimet and allows the company to proceed with its planned U.S. Phase 3 development program. Acne is one of the most prevalent skin conditions in the United States, affecting millions of people and particularly adolescents and young adults. Moderate to severe disease can require repeated treatment and long-term disease management, creating demand for additional therapeutic options. If the Phase 3 study demonstrates statistically and clinically meaningful improvements across its co-primary endpoints while maintaining an acceptable safety profile, denifanstat could advance toward potential regulatory submission for acne. Nevertheless, the current FDA clearance only authorizes the clinical study to proceed; it does not establish the drug’s efficacy, safety or approval status. The upcoming 12-week randomized period and 40-week extension will therefore be critical in determining whether denifanstat can successfully progress toward commercialization as a novel oral FASN inhibitor for moderate to severe acne.
Source: Sagimet Biosciences,press release
