'Exciting Time for NASH' With Resmetirom
Phase 3 Results

Becky McCall

June 22, 2023

VIENNA — Resolution of non-alcoholic steatohepatitis (NASH), and reduction of fibrosis on liver biopsy were achieved with the oral, thyroid hormone receptor beta-selective agonist resmetirom (Madrigal Pharmaceuticals) in patients with NASH and associated cirrhosis in a pivotal phase 3 clinical trial. The primary results of the MAESTRO-NASH (NCT03900429) trial were reported here at the European Association for the Study of the Liver (EASL) Congress 2023.

Both doses of resmetirom — 80 mg and 100 mg — met the primary endpoints of NASH resolution and no worsening of fibrosis on liver biopsy. The key secondary endpoint of LDL cholesterol lowering was also achieved with statistical significance. Likewise, improvement was seen in liver enzymes, and liver and spleen volumes.

In the intent to treat population, NASH resolution was achieved in 26% (P < .0001) in the 80 mg resmetirom group, 30% (P < .0001) in the 100 mg group, and 10% in those taking placebo. And ≥1-stage improvement in fibrosis with no worsening of the NAFLD activity score (NAS) was achieved by 24% (P < .0002), 26% (P < .0001), and 14% in these groups respectively.

The investigational, liver-directed agent, designed to improve NASH by increasing hepatic fat metabolism and reducing lipotoxicity, was well-tolerated overall with a favorable safety profile.

"This is an exciting time for NASH because we are at the forefront of having a drug to treat these patients, and the benefit to patients promises to be huge," asserted Stephen Harrison, MD, gastroenterologist and hepatologist, principal investigator of the MAESTRO studies, and chairman of Pinnacle Clinical Research and Summit Clinical Research, San Antonio, Texas, reporting 52-week results.

"This is the first treatment to achieve meaningful effects on both primary liver biopsy endpoints — disease activity and fibrosis — which is absolutely critical because fibrosis pertains to a worse prognosis. [These results] are reasonably likely to predict clinical benefit in a phase 3 trial in patients with NASH," he added.

FDA-Chosen Endpoints Likely to Predict Clinical Outcomes

The ongoing 54-month, phase 3, registrational, double blind, placebo-controlled trial involved taking liver biopsies from 966 patients at around 200 global sites. Biopsy readings were taken by two pathologists that were then combined into a single treatment effect. 

Patients had biopsy-proven NASH with fibrosis stages F1B, F2, or F3, the presence of three or more metabolic risk factors, a FibroScan vibration-controlled transient elastography (VCTE) score of 8.5 kPa or more, baseline MRI proton density fat fraction (MRI-PDFF) of 8% or more, and a NAS score of 4 or more with at least 1 in each NAS component. Around 65% of participants had type 2 diabetes, between 13% and 16% were taking glucagon-like peptide-1 (GLP-1) receptor agonists, and 46%–51% were taking statins.

Patients were randomized 1:1:1 to once-daily resmetirom 80 mg or 100 mg orally or to placebo and treated for 52 weeks.

Both liver histological improvement primary endpoints at week-52 were proposed by the US Food and Drug Administration (FDA) as reasonably likely to predict clinical benefit and as such support accelerated approval for the treatment of NASH with liver fibrosis. These primary endpoints were NASH resolution (ballooning 0, inflammation 0/1) with ≥2 point improvement in NAS with no worsening of fibrosis, and ≥1-stage reduction in fibrosis with no worsening of NAS.

Patients on resmetirom showed improvement in NAS components and fibrosis, and less worsening of NAS and fibrosis compared with placebo. Percentage improvement was seen in 31%, 33%, and 15% of patients on 80 mg resmetirom, 100 mg resmetirom, and placebo respectively; no change was seen in 51%, 48%, and 51% respectively; and worsening was seen in 18%, 19%, and 34% respectively. 

The key secondary endpoint of LDL cholesterol lowering was also met. "There was a significant effect of resmetirom 80 and 100 mg on multiple atherogenic lipids/lipoproteins at both week 24 and 52," reported Harrison. The 52-week percentage change from baseline in LDL cholesterol was -14%, -20%, and 0% for the 80 mg resmetirom group, the 100 mg group, and the placebo group respectively.

"We also saw a significant reduction in liver enzymes [alanine transaminase (ALT), aspartate transaminase (AST) and gamma-glutamyl transferase (GGT)] relative to placebo both in terms of percentage and absolute measures," Harrison added. "[And] the change in liver enzymes was associated with the neutral biomarker that increases with resmetirom target engagement."   

Resmetirom at both doses also resulted in a significant effect on MRI-PDFF and Fibroscan CAP. At week 52, 80 mg resmetirom, 100 mg, and placebo led to -42.1%, -51.4% and -10.4% change from baseline in MRI-PDFF, while Fibroscan CAP changed by -39.6%, -41.3%, and -14.5% respectively, reported Harrison. Liver volume dropped by -21.6% in the 80 mg group, -25.8% in the 100 mg group, compared with -1.0% in the placebo group. Spleen volume changed by -5.9%, -6.1%, and +3.2% respectively.

Liver stiffness, as measured by Fibroscan VCTE at week 52, changed from -3.7 KPa (F1B) to -2.0 KPa (F3) at 80 mg, and from -3.7 KPa (F1B) to -2.5 KPa (F2) and -3.3 KPa (F3) at the 100 mg dose.

Further analysis showed that improvements in fibrosis and NASH resolution were seen across all key subgroups, including baseline fibrosis stage (F2 or F3), NAS (<6, ≥6), type 2 diabetes status, age (<65 years, ≥65 years), and sex.

Safety Profile

"The safety profile of resmetirom in the MAESTRO-NASH trial is consistent with previous phase 2/3 trials in which the most common adverse events were diarrhea and nausea at treatment initiation," said Harrison.

Study discontinuations in the 100 mg group were increased relative to placebo during the first few weeks of treatment and were similar in all treatment groups up to 52 weeks. Discontinuations of patients on resmetirom 100 mg were mainly gastrointestinal-related. 

Phase 2 results of the serial liver biopsy trial in adults with biopsy-confirmed NASH showed that resmetirom resolved NASH in a significantly greater percentage of patients and reduced liver enzymes, inflammatory biomarkers, and fibrosis compared with placebo.

We've been waiting for a long, long time for a therapy for these patients. Stephen Harrison, MD, lead investigator of the MAESTRO-NASH trial

"We've been waiting for a long, long time for a therapy for these patients because until now, they've have been challenged with lifestyle modifications to lose and maintain weight," said Harrison. "There's been a delay in identifying patients with this disease because we've had no treatment, but now that we are on the forefront of a treatment, it allows clinicians to open their minds to the possibility of identifying these patients."

Harrison noted that a limitation of these data were the lack of clinical outcomes data to correlate with the biopsy data; however, the MAESTRO-NASH trial will continue to 54 months to accrue and evaluate clinical outcomes.

Milan Mishkovikj, MSc, board director of the European Liver Patients Association (ELPA), North Macedonia, commented on the potential benefit of this drug for patients. "Adhering to a healthy lifestyle is not always easy — not in all countries — so it’s encouraging to have a drug that hopefully is affordable and accessible to us. Now we need to manage the expectations of patients and caregivers."

EASL's vice secretary Aleksander Krag, MD, PhD, professor and head of hepatology at University of Southern Denmark and Odense University Hospital remarked, "This is so exciting. This phase 3 trial is a real game-changer in the field of fatty liver disease because it has nearly 1000 patients over 52 weeks of treatment."

Madrigal Pharmaceuticals plans to submit an application to the FDA by end of the second quarter with a priority review.

Harrison reports being a scientific advisor or consultant for Akero, Aligos, Altimmune, Arrowhead, BluejayTherapeutics, BoxerCapital, Chronwell, Echosens, Enyo, ForesiteLabs, Galectin, Galecto, Gilead, GSK, Hepagene, Hepion, HeptaBio, HistoIndex, Humana, Intercept, Ionis, Madrigal, Medpace, NeuroBo Pharmaceuticals, Northsea, NovoNordisk, Perspectum, Pfizer, Sonic Incytes, Sagimet, Terns, and Viking; having stock options in Akero, Chronwell, Cirius, Galectin, Genfit, Hepion, HeptaBio, HistoIndex, Metacrine, NGMBio, Northsea, and Sonic Incytes; grant/research support from Akero, Altimmune, Axcella, BMS, Corcept, Cymabay, Enyo, Galectin, Genentech, Genfit, Gilead, GSK, Hepion, Hightide, Immuron, Intercept, Inventiva, Ionis, Madrigal, NGMBio, Novartis, NovoNordisk, Northsea, Pfizer, Poxel, Sagimet, Terns, and Viking.

Krag has served as speaker for Norgine, Siemens, and Nordic Bioscience, and participated in advisory boards for Norgine and Siemens, all outside the submitted work. He receives royalties from Gyldendal and Echosens. Mishkovikj has declared no relevant financial relationships.

European Association for the Study of the Liver (EASL) Congress 2023: Abstract GS-001. Presented June 22, 2023.

For more news, follow Medscape on Facebook, Twitter, Instagram, YouTube, and LinkedIn


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.