MILAN — Tirzepatide, a glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) receptor agonist, was more effective than placebo was in the resolution of metabolic dysfunction–associated steatohepatitis (MASH) and in the improvement of fibrosis, according to the results of the phase 2 SYNERGY-NASH trial.
Specifically, 44%-62% of participants with MASH and moderate or severe fibrosis treated with 5-15 mg of tirzepatide achieved MASH resolution without worsening of fibrosis compared with 10% on placebo; 51%-55% of those on tirzepatide achieved at least one stage of fibrosis improvement without worsening of MASH compared with 30% on placebo. Tirzepatide also led to weight loss.
The study (Abstract LBO-001) was presented at the European Association for the Study of the Liver (EASL) Congress 2024by Rohit Loomba, MD, professor of medicine, NAFLD Research Center, University of California at San Diego in La Jolla, and published simultaneously in The New England Journal of Medicine.
"The results are clinically meaningful," Loomba told Medscape Medical News.
Both of the endpoints — improvements in MASH resolution and fibrosis — are considered approvable endpoints for MASH therapeutic development, and therefore, increase the likelihood of success of using such a strategy in a phase 3 setting, Loomba said.
MASH Resolution, No Worsening of Fibrosis
The dose-finding, multicenter, double-blind, placebo-controlled trial randomly assigned a total of 190 participants to receive once-weekly subcutaneous tirzepatide (5 mg, 10 mg, or 15 mg) or placebo for 52 weeks. Participants had biopsy-confirmed MASH and stage F2 or F3 (moderate or severe) fibrosis.
Overall, approximately 42% of participants had F2 fibrosis and over 57% had F3 fibrosis. The proportion of F3 fibrosis was numerically higher in the placebo (64.6%) and 5-mg tirzepatide (63.8%) groups.
The mean age of the study cohort was 54 years; 57% were female, 86% were White, and 36% were Hispanic; the mean body mass index was 36; 58%had type 2 diabetes; and A1c was 6.5. NAFLD activity score (NAS) was 5.3. Baseline noninvasive test results were consistent with the study population of MASH with F2/F3 fibrosis and NAS ≥ 4.
The primary endpoint was resolution of MASH without worsening of fibrosis at 52 weeks, and the key secondary endpoint was an improvement (decrease) of at least one fibrosis stage without worsening of MASH. Other secondary endpoints included a ≥ 2-point decrease in NAS with ≤ 1-point decrease in two or more NAS components.
A total of 157 participants (83%) underwent liver biopsies at week 52, providing results for the current analysis.
Among tirzepatide-treated patients, 43.6% in the 5-mg group, 55.5% in the 10-mg group, and 62.4% in the 15-mg group met the criteria for resolution of MASH without worsening of fibrosis compared with 10% in the placebo group (P < .001 for all three comparisons).
Fibrosis improved by at least one stage without worsening of MASH in 54.9% of participants in the 5-mg tirzepatide group, 51.3% in the 10-mg tirzepatide group, and 51.0% in the 15-mg tirzepatide group compared with 29.7% in the placebo group (P < .001 for all risk differences with placebo).
Changes in NAS and subscores for the individual components of NAS, including steatosis, lobular inflammation, and hepatocellular ballooning, were also seen in participants on tirzepatide.
The researchers used a composite endpoint of a ≥ 2-point decrease in NAS with a ≥ 1-point decrease in at least two NAS components. Of the tirzepatide-treated groups, 71.7%,78.3%, and 76.6% in the 5-mg, 10-mg, and 15-mg groups, respectively, met this endpoint compared with 36.7% in placebo.
Imaging of liver fat with MRI-based proton density fat fraction (MRI-PDFF) showed reductions from baseline of -45.7, -41.3, -57.0 in participants on 5-mg, 10-mg, and 15-mg tirzepatide, respectively. Differences from placebo were all statistically significant.
Percentage of body weight change from baseline was -10.7%, -13.3%, and -15.6% in the 5-mg, 10-mg, and 15-mg tirzepatide groups, respectively, compared with weight loss of -0.8% in the placebo group.
" Tirzepatide led to significant weight loss in both patients with diabetes and those without diabetes," reported Loomba.
There were more adverse events in patients on tirzepatide (92.3%) compared with patients on placebo (83.3%).
"The most common adverse events were gastrointestinal in nature, with 96% of them mild to moderate in severity," said Loomba. "Discontinuations occurred in 4.2% of participants, which was similar between patients on tirzepatide and those on placebo."
He pointed out that the safety profile of tirzepatide in a MASH population "was generally similar to that observed in the phase 3 trials of type 2 diabetes and obesity."
Incidence of serious adverse events was also similar at 6.3% for participants on tirzepatide vs 6.2% for those on placebo; 2.8% on tirzepatide and 4.2% on placebo progressed to cirrhosis. There was no evidence of drug-induced liver injury.
'Convincing Results'
Commenting on the study, co-moderator Sven Francque, MD, hepatologist and head of department at the University Hospital of Antwerp, Belgium, said that the study was in a relatively "severe" patient population, which was one of its strengths.
"These are convincing results in terms of MASH resolution, showing a strong response and dose-dependence," he said.
"In terms of fibrosis, the results look numerically strong but are somewhat more puzzling to interpret, as there was no dose-response relationship and no data on NITs [noninvasive tests] that could support the results," he added.
"Patients with no-end-of-treatment biopsies were handled differently than in previous trials, which makes it difficult to appreciate antifibrotic potency," he said. But "such a strong effect on MASH should translate into a reduction in fibrosis even in the absence of direct antifibrotic effects."
Given that "about one third of patients in the active treatment arms" did not have end-of-treatment biopsy, these "are rather small numbers precluding firm conclusions," he added.
However, Francque said that he believes the findings are compelling enough for the drug to go into phase 3 trials.
Francque has no disclosures of relevance to this study. Loombaserves as a consultant to Aardvark Therapeutics, Altimmune, Anylam/Regeneron, Amgen, Arrowhead Pharmaceuticals, AstraZeneca, Bristol Myer Squibb, CohBar, Eli Lilly, Galmed, Gilead, Glympse Bio, Hightide, Inipharma, Intercept, Inventiva, Ionis, Janssen, Madrigal, Metacrine, NGM Biopharmaceuticals, Novartis, Novo Nordisk, Merck, Pfizer, Sagimet, Theratechnologies, 89 bio, Terns Pharmaceuticals and Viking Therapeutics. In addition, his institutions received research grants from Arrowhead Pharmaceuticals, AstraZeneca, Boehringer-Ingelheim, Bristol Myers Squibb, Eli Lilly, Galectin Therapeutics, Galmed Pharmaceuticals, Gilead, Intercept, Hanmi, Intercept, Inventiva, Ionis, Janssen, Madrigal Pharmaceuticals, Merck, NGM Biopharmaceuticals, Novo Nordisk, Merck, Pfizer, Sonic Incytes, and Terns Pharmaceuticals. Loomba is also a co-founder of LipoNexus.
