BACKGROUND: Denifanstat, an oral fatty acid synthase (FASN) inhibitor, blocks de-novo lipogenesis, a key pathway driving progressive lipotoxicity, inflammation, and fibrosis in metabolic dysfunction-associated steatohepatitis (MASH). This study aimed to examine the safety and efficacy of denifanstat for improving liver histology in individuals with MASH and moderate to advanced fibrosis.
METHODS: This multicentre, double-blind, randomised, placebo-controlled, phase 2b trial was conducted at 100 clinical sites in the USA, Canada, and Poland. After a screening period of up to 90 days, participants aged 18 years and older with biopsy-confirmed MASH and stage F2 or F3 fibrosis were randomly assigned (2:1) to receive either 50 mg oral denifanstat or placebo once per day for 52 weeks. Participants were dynamically allocated to treatment groups via a centrally administered interactive web-based response system and stratified by type 2 diabetes, region, and fibrosis stage. Investigators, patients, and the sponsor were masked to group allocation until database lock. The primary efficacy endpoints were a 2-point or greater improvement in non-alcoholic fatty liver disease activity score (NAS) without a worsening of fibrosis or MASH resolution with a 2-point or greater improvement in NAS without a worsening of fibrosis at week 52, assessed by intention to treat. Safety was assessed in all participants who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov, NCT04906421, and is closed for enrolment.
FINDINGS: Of the 1087 individuals screened between June 2, 2021, and June 28, 2022, 168 eligible participants were randomly assigned to receive a dose of 50 mg denifanstat once per day (n=112) or placebo (n=56). All 168 participants (100 female, 68 male) received at least one dose of study treatment. In the ITT population, 42 (38%) of 112 participants in the denifanstat group had a 2-point or greater improvement in NAS without a worsening of fibrosis versus nine (16%) of 56 participants in the placebo group (common risk difference 21·0%, 95% CI 8·1-33·9; p=0·0035). 29 (26%) of 112 participants in the denifanstat group showed MASH resolution with a 2-point or greater improvement in NAS without a worsening of fibrosis compared with six (11%) of 56 participants in the placebo group (common risk difference 13·0%, 0·7-25·3; p=0·0173). The most common treatment-emergent adverse events were COVID-19 (19 [17%] of 112 in the denifanstat group vs six [11%] of 56) in the placebo group, dry eye symptoms (ten [9%] of 112 vs eight [14%] of 56), and alopecia (21 [19%] of 112 vs two [4%] of 56). All adverse events considered to be related to the study drug were of grade 1 or grade 2. None of the serious adverse events (13 [12%] of 112 participants in the denifanstat group vs three [5%] of 56 in the placebo group) were considered drug-related.
INTERPRETATION: Treatment with denifanstat resulted in statistically significant and clinically meaningful improvements in disease activity, MASH resolution, and fibrosis. The results of this phase 2b trial support the advancement of denifanstat to phase 3 development.
FUNDING: Sagimet Biosciences.
