SAN MATEO, Calif. — February 2, 2026 — Leads & Copy — Sagimet Biosciences Inc. (Nasdaq: SGMT) announced that Ascletis Pharma Inc. issued a press release on January 29th, reporting positive topline results from an open-label Phase 3 trial. The trial evaluated the long-term safety of ASC40 (denifanstat) tablets in patients with moderate to severe acne.
Denifanstat, developed by Ascletis as ASC40 for acne in China and by Sagimet for MASH globally, is a once-daily oral small molecule fatty acid synthase (FASN) inhibitor. Sagimet has granted Ascletis Bioscience Co. Ltd. (Ascletis), the parent company of Ascletis Pharma Inc., an exclusive license to denifanstat for China.
David Happel, Chief Executive Officer of Sagimet, stated that the topline results from Ascletis’ Phase 3 open-label acne trial in China increase confidence in the clinical potential of FASN inhibition in acne. Happel added that the results demonstrate FASN inhibition’s potential as a novel mechanism of action for the treatment of acne.
In June 2025, Ascletis announced that denifanstat (ASC40) met all primary, key secondary, and secondary endpoints in a 480-patient randomized, double-blind, placebo-controlled Phase 3 clinical trial (NCT06192264, ASC40-303) for the treatment of moderate to severe acne vulgaris.
Dr. Neal Bhatia, Director of Clinical Dermatology at Therapeutics Clinical Research in San Diego and former Vice President of the American Academy of Dermatology, noted that the results from the 40-week open-label study are encouraging, following the 12-week data from the Phase 3 randomized double-blind denifanstat trial. Bhatia added that the potential of a new therapeutic option would be a welcome addition to the current treatment for moderate to severe acne patients underserved by older agents.
The Phase 3 multi-center open-label clinical trial ASC40-304 (NCT06248008) was designed to determine the long-term safety of denifanstat in patients with moderate to severe acne vulgaris previously enrolled in the double-blind, randomized, placebo-controlled 12-week Phase 3 ASC40-303 trial. The trial enrolled 240 subjects who received oral denifanstat 50 mg once daily for up to 40 weeks. Subjects originally randomized to denifanstat in the ASC40-303 trial had a total of 52 weeks of denifanstat exposure.
The primary endpoints evaluated safety, and secondary endpoints evaluated efficacy, for up to 52 weeks of denifanstat treatment. Denifanstat was generally well tolerated. Only two categories of treatment-emergent adverse events (TEAEs) had an incidence rate of 5% or more: dry eye syndrome in 5.5% of denifanstat-treated subjects and dry skin reported in 5.2% of denifanstat-treated subjects.
All denifanstat-related adverse events (AEs) were mild or moderate; no denifanstat-related Grade 3 or 4 AEs were reported, and there were no AE-related permanent discontinuations. Grade 1 hair thinning was experienced by only one denifanstat-treated patient (which resolved within eight weeks while remaining in the study without a change in dose), and no deaths were reported.
No denifanstat-related serious adverse events (SAEs) were reported. There were two non-denifanstat-related SAEs (one breast lump and one contusion), both of which resolved.
Subjects treated with denifanstat showed improvements in all efficacy endpoints (secondary endpoints of the trial) beyond those observed at 12 weeks. The endpoints were the number of subjects with an IGA1 score decrease by at least 2 points, the number of subjects dropping from an IGA score of 3 down to 0 or 1, the percentage reduction in total skin lesion count, and the percentage reduction in inflammatory skin lesion count. Data are planned to be shared in upcoming congresses and publications.
Sagimet Biosciences is a clinical-stage biopharmaceutical company developing novel FASN inhibitors to target dysfunctional metabolic and fibrotic pathways. Denifanstat, an oral, once-daily pill, met all primary endpoints in its Phase 2b FASCINATE-2 clinical trial in MASH and all primary and secondary endpoints in Sagimet’s license partner for China’s Phase 3 clinical trial in moderate-to-severe acne. A combination of denifanstat and resmetirom was tested in a Phase 1 PK clinical trial and is planned to be developed for patients with MASH cirrhosis (F4). TVB-3567, a second oral FASN inhibitor planned for acne development, is currently being tested in a Phase 1 first-in-human clinical trial.
Over 50 million people suffer from acne in the U.S., with 5.1 million acne patients treated by dermatologists annually. There is no cure for acne; and due to its pathology, most patients require chronic management and multiple annual courses of treatment for flare control. Adherence to topical therapies is lower than with oral agents, with an estimated 30% to 40% of patients not adhering to their topical treatments.
Patients with acne vulgaris have increased sebum production compared to non-acne populations, which contributes to the pathogenesis of the disease. Increased sebum production is due to increased de novo lipogenesis (DNL) locally in the sebocytes. FASN is the last committed step in the DNL pathway which produces the majority (>80%) of key sebum lipids such as palmitate and sapienic acid in acne, and FASN also contributes to inflammatory pathways, making the inhibition of FASN a potentially impactful approach to address acne.
Source: Sagimet Biosciences
