Sagimet Clears FDA Hurdle to Move Denifanstat into Phase 3 for Acne

The planned 800-patient U.S. study will test an oral FASN inhibitor in moderate to severe acne, including approximately 450 adolescents.

Sagimet Biosciences (Nasdaq: SGMT) is moving denifanstat toward late-stage development in the U.S. after receiving FDA clearance to begin a Phase 3 trial in moderate to severe acne.

The FDA issued a “Study May Proceed” letter and cleared the Investigational New Drug application for the trial, which Sagimet expects to initiate in the second half of 2026, with patient dosing also expected to begin this year.

The milestone moves a new mechanism into U.S. Phase 3 development for a condition that affects approximately 50 million Americans annually. Sagimet estimates that moderate to severe acne accounts for roughly 10 million of those patients.

An 800-Patient Phase 3

The multicenter, randomized, double-blind study is designed to enroll approximately 800 U.S. patients ages 12 and older, including an expected 450 adolescents between 12 and 17.

Participants will be randomized 2:1 to receive either 50 mg of denifanstat or placebo once daily for 12 weeks.

At Week 12, investigators will assess three co-primary endpoints: treatment success based on a global assessment score, change in inflammatory lesion counts and change in non-inflammatory lesion counts.

Patients who complete the randomized portion will be eligible to continue into a 40-week open-label extension evaluating long-term safety.

A Different Approach to Acne

Denifanstat is an oral, once-daily inhibitor of fatty acid synthase, or FASN, an enzyme involved in lipid synthesis. Sagimet is developing the drug for moderate to severe acne as part of a broader FASN platform targeting diseases associated with dysfunctional metabolic and fibrotic pathways.

The U.S. study will not be the first Phase 3 test of denifanstat in acne. Sagimet’s licensing partner, Ascletis BioScience, is developing the drug as ASC40 in China, where it met all primary and secondary endpoints in a randomized, double-blind Phase 3 trial in moderate to severe acne vulgaris. Sagimet also reported that an open-label Phase 3 study showed improvements across efficacy measures through 52 weeks and that the treatment was generally well tolerated.

Ascletis holds development rights in China, while Sagimet is developing denifanstat in the rest of the world.

What Comes Next

With the IND now cleared, attention shifts to the start of the U.S. Phase 3 trial in the second half of 2026.

The size of the study, its substantial adolescent enrollment and the 40-week safety extension should provide a broader test of whether the efficacy and tolerability previously observed in China can translate to a U.S. patient population.

For Sagimet, that makes the FDA clearance more than an administrative milestone: denifanstat is now cleared to enter the study intended to establish its late-stage clinical case in the U.S. acne market.