Safety and efficacy of once-weekly efruxifermin versus placebo in metabolic dysfunction-associated steatohepatitis (HARMONY): 96-week results from a multicentre, randomised, double-blind, placebo-controlled, phase 2b trial.

BACKGROUND

Efruxifermin is a bivalent fibroblast growth factor 21 analogue in development for the treatment of metabolic dysfunction-associated steatohepatitis (MASH). This trial aimed to prospectively assess the safety and efficacy of efruxifermin administration for 96 weeks in individuals with MASH and moderate (stage 2; F2) or severe (stage 3; F3) fibrosis.

METHODS

HARMONY is a multicentre, randomised, double-blind, placebo-controlled, phase 2b trial conducted at 41 academic and community centres in the USA. Adults (aged 18-75 years) with biopsy-confirmed MASH (defined as non-alcoholic fatty liver disease activity score of 4 or higher and a score of 1 or higher for steatosis, ballooning, and lobular inflammation), with histological stage F2 or F3 fibrosis, were randomly assigned (1:1:1), via an interactive response system, to receive subcutaneous efruxifermin (28 mg or 50 mg) once per week or placebo. Participants, investigators, pathologists, site staff, and the sponsor were masked to group assignments. The primary endpoint was an improvement in liver fibrosis (decrease ≥1 stage) without worsening of MASH at week 24, which has been previously reported. End-of-treatment endpoints at week 96 included a final evaluation of the primary endpoint, as well as MASH resolution without fibrosis worsening. The trial is registered with ClinicalTrials.gov, NCT04767529, and is complete.

FINDINGS: Between March 22, 2021, and Feb 7, 2022, 128 participants were randomly assigned and 126 received at least one dose of efruxifermin or placebo and were included in the modified intention-to-treat analysis. 79 (62%) of 128 participants were female and 49 (38%) were male. The proportion of participants in the modified intention-to-treat population with ≥1-stage fibrosis improvement without MASH worsening at week 96 was eight (19%) of 43 in the placebo group, 12 (30%) of 40 in the 28 mg group (difference vs placebo: 12 percentage points [95% CI -6 to 31]; p=0·19), and 21 (49%) of 43 in the 50 mg group (difference: 31 percentage points [12 to 49]; p=0·0030). Of 88 participants with week-96 biopsies, ≥1-stage fibrosis improvement without MASH worsening was observed in eight (24%) of 34 participants in the placebo group, 12 (46%) of 26 in the 28 mg group (difference vs placebo: 22 percentage points [95% CI -1 to 45]; p=0·070), and 21 (75%) of 28 in the 50 mg group (difference: 52 percentage points, [31 to 73]; p<0·0001). 38 (95%) of 40 participants in the 28 mg group, 43 (100%) of 43 in the 50 mg group, and 42 (98%) of 43 in the placebo group reported an adverse event. Mild to moderate gastrointestinal adverse events were more common with efruxifermin than placebo. There were no reports of drug-induced liver injury or deaths across the groups.

INTERPRETATION: Efruxifermin resulted in greater improvements in fibrosis than placebo after 96 weeks, warranting further investigation in phase 3 trials.

FUNDING: Akero Therapeutics.