Can We Repurpose Obesity Drugs to Reverse Liver Disease?

Metabolic dysfunction–associated steatotic liver disease (MASLD) has become the most common liver disease worldwide, with a global prevalence of 32.4%. Its growth over the past three decades has occurred in tandem with increasing rates of obesity and type 2 diabetes — two cornerstones of MASLD.

Higher rates of MASLD and metabolic dysfunction–associated steatohepatitis (MASH) with fibrosis are present in adults with obesity and diabetes, noted Arun Sanyal, MD, professor and director of the Stravitz-Sanyal Institute for Liver Disease and Metabolic Health, Virginia Commonwealth University, Richmond, Virginia.

The success surrounding the medications for obesity and type 2 diabetes, including glucagon-like peptide 1 receptor agonists (GLP-1 RAs), has sparked studies investigating whether they could also be an effective treatment for liver disease.

In particular, GLP-1 RAs help patients lose weight and/or control diabetes by mimicking the function of the gut hormone GLP-1, released in response to nutrient intake, and are able to increase insulin secretion and reduce glucagon secretion, delay gastric emptying, and reduce appetite and caloric intake.

The studies for MASLD are testing whether these functions will also work against liver disease, either directly or indirectly, through obesity and diabetes control. The early results are promising.

More Than One Risk Factor in Play

MASLD is defined by the presence of hepatic steatosis and at least one of five cardiometabolic risk factors: Overweight/obesity, hypertension, hyperglycemia, dyslipidemia with either low-plasma high-density lipoprotein cholesterol or high triglycerides, or treatment for these conditions.

It is a grim trajectory if the disease progresses to MASH, as the patient may accumulate hepatic fibrosis and go on to develop cirrhosis and/or hepatocellular carcinoma.

Typically, more than one risk factor is at play in MASLD, noted Adnan Said, MD, chief of the Division of Gastroenterology and Hepatology at the William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin.

“It most commonly occurs in the setting of weight gain and obesity, which are epidemics in the United States and worldwide, as well as the associated condition — metabolic syndrome — which goes along with obesity and includes type 2 diabetes, hyperlipidemia, hypertension, and sleep apnea,” Said, a hepatology and gastroenterology professor at the University of Wisconsin–Madison, told Medscape Medical News.

The research surrounding MASLD is investigating GLP-1 RAs as single agents and in combination with other drugs.

Finding treatment is critical, as there is only one drug — resmetirom — approved for the treatment of MASH with moderate to advanced fibrosis. But because it’s not approved for earlier stages, a treatment gap exists. The drug also doesn’t produce weight loss, which is key to treating MASLD. And while GLP-1 RAs help patients with the weight loss that is critical to MASLD, they are only approved by the US Food and Drug Administration (FDA) for obesity and type 2 diabetes.

Single Agents

The GLP-1 RAs liraglutide and semaglutide, both approved for diabetes and weight loss, are being studied as single agents against liver disease, Said said.

“Their action in the setting of MASLD and MASH is primarily indirect, through systemic pathways, improving these conditions via weight loss, as well as by improving insulin sensitivity and reducing lipotoxicity,” he added.

One of the first trials of these agents for liver disease was in 2016. In that double-blind, randomized, 48-week clinical trial of liraglutide in patients with MASH and overweight, 39% of patients who received liraglutide had a resolution of MASH compared with only 9% of those who received placebo. Moreover, only 9% vs 36% of patients in the treatment vs placebo group had progression of fibrosis.

Since then, a 72-week phase 2 trial in patients with MASH, liver fibrosis (stages F1-F3), and overweight or obesity found that once-daily subcutaneous semaglutide (0.1, 0.2, or 0.4 mg) outperformed placebo on MASH resolution without worsening of fibrosis (36%-59% vs 17%) and on weight loss (5%-13% vs 1%), with the greatest benefits at the largest dose. However, neoplasms were reported in 15% of patients receiving semaglutide vs 8% of those receiving placebo.

A phase 1 trial involving patients with liver stiffness, steatosis, and overweight or obesity found significantly greater reductions in liver fat at 48 weeks with semaglutide vs placebo, as well as decreases in liver enzymes, body weight, and A1c. There was no significant difference in liver stiffness.

Furthermore, a meta-analysis of eight studies found that treatment with 24 weeks of semaglutide significantly improved liver enzymes, reduced liver stiffness, and improved metabolic parameters in patients with MASLD/MASH. The authors cautioned that gastrointestinal adverse effects “could be a major concern.”

Several studies have found other GLP-1 RAs, including exenatide and dulaglutide, have a beneficial impact on liver injury indices and liver steatosis.

A new retrospective observational study offers evidence that GLP-1 RAs may have a direct impact on MASLD, independent of weight loss. Among the 28% of patients with type 2 diabetes and MASLD who received a GLP-1 RA, there was a significant reduction not only in body mass index but also in A1c, liver enzymes, and controlled attenuation parameter scores. A beneficial impact on liver parameters was observed even in patients who didn’t lose weight. While there was no difference in liver stiffness measurement, the median 60-month follow-up time may not have been long enough to capture such changes.

Another study indicated that the apparent benefits of GLP-1 RAs, in this case semaglutide, may not extend to patients whose disease has progressed to cirrhosis.

Dual and Triple Mechanisms of Action

Newer agents with double or triple mechanisms of action appear to have a more direct effect on the liver.

“Dual agents may have an added effect by improving MASLD directly through adipose regulation and thermogenesis, thereby improving fibrosis,” Said said.

An example is tirzepatide, a GLP-1 RA and an agonist of glucose-dependent insulinotropic polypeptide (GIP). Like GLP-1, GIP is an incretin. When used together as co-agonists, GLP-1 and GIP have been shown to increase insulin and glucagonostatic response and may work synergistically.

A new phase 2 trial that randomly assigned patients with biopsy-confirmed MASH and moderate or severe fibrosis to receive either once-weekly subcutaneous tirzepatide at one of three doses (5, 10, or 15 mg) or placebo found that tirzepatide at each dosage outperformed placebo in resolution of MASH without worsening of fibrosis.

“These findings were encouraging,” Said said. “We’ll see if the results continue into phase 3 trials.”

The combination of GLP-1 RAs with glucagon (GCG) receptor agonists also has garnered interest.

In a phase 2 trial, adults with biopsy-confirmed MASH and fibrosis stages F1-F3 were randomly assigned to receive either one of three doses of the GLP-1/GCG RA survodutide (2.4, 4.8, or 6 mg) or placebo. Survodutide at each dose was found to be superior to placebo in improving MASH without the worsening of fibrosis, reducing liver fat content by at least 30%, and decreasing liver fibrosis by at least one stage, with the 4.8-mg dose showing the best performance for each measure. However, adverse events, including nausea, diarrhea, and vomiting, were more frequent with survodutide than with placebo.

Trials of triple-action agents (GLP-1/GIP/GCG RAs) are underway too.

The hope is the triple agonists could deliver greater reduction in hepatic fat in patients with MASLD, Sanyal said. 

Sanyal further noted that a reduction in liver fat is important, citing a meta-analysis that showed ≥ 30% relative decline in liver fat is associated with higher odds of histologic response and MASH resolution.

Sanyal pointed to efocipegtrutide (HM15211), a GLP-1/GIP/GCG RA, which demonstrated significant liver fat reduction after 12 weeks in patients with MASLD in a phase 1b/2a randomized, placebo-controlled trial and is now in phase 2 development.

Another example is retatrutide (LY3437943), a once-weekly injectable, that was associated with up to a 24.2% reduction in body weight at 48 weeks, compared with 2.1% with placebo, in a phase 2 trial involving patients with obesity.

A sub-study assessed the mean relative change from baseline in liver fat at 24 weeks. These participants, who also had MASLD and ≥ 10% of liver fat content, were randomly assigned to receive either retatrutide in one of four doses (1, 4, 8, or 12 mg) or placebo for 48 weeks. All doses of retatrutide showed significantly greater reduction in liver fat content compared with placebo in weeks 24-48, with a mean relative liver fat reduction > 80% at the two higher doses. Moreover, ≥ 80% of participants on the higher retatrutide doses experienced ≥ 70% reduction in liver fat at 48 weeks, compared with 0% reduction in those on placebo, and hepatic steatosis resolved in > 85% of these participants.

This space “continues to evolve at a rapid rate,” Sanyal said. For example, oral dual-action agents are under development.

Obstacles and Warnings

Sanyal warned that GLP-1 RAs can cause nausea, so they have to be introduced at a low dose and slowly titrated upward. They should be used with caution in people with a history of multiple endocrine neoplasia. There is also a small but increased risk for gallstone formation and gallstone-induced pancreatitis with rapid weight loss.

GLP-1 RAs may increase the risk for suicidal ideation, with the authors of a recent study calling for “urgent clarification” regarding this possibility.

Following reports of suicidality submitted through its Adverse Events Reporting System, the FDA concluded that it could find no causal relationship between these agents and increased risk for suicidal ideation but also that it could not “definitively rule out that a small risk may exist” and would continue to investigate.

Access to GLP-1 RAs is an obstacle as well. Semaglutide continues to be on the FDA’s shortage list.

“This is improving, but there are still issues around getting approval from insurance companies,” Sanyal said.

Many patients discontinue use because of tolerability or access issues, which is problematic because most regain the weight they had lost while on the medication.

“Right now, we see GLP-1 RAs as a long-term therapeutic commitment, but there is a lot of research interest in figuring out if there’s a more modest benefit — almost an induction-remission maintenance approach to weight loss,” Sanyal said. These are “evolving trends,” and it’s unclear how they will unfold.

“As of now, you have to decide that if you’re putting your patient on these medications, they will have to take them on a long-term basis and include that consideration in your risk-benefit analysis, together with any concerns about adverse effects,” he said.

Sanyal reported consulting for Boehringer Ingelheim, Eli Lilly, and Novo Nordisk. Said received research support from Exact Sciences, Boehringer Ingelheim, and Mallinckrodt.

Batya Swift Yasgur, MA, LSW, is a freelance writer with a counseling practice in Teaneck, New Jersey. She is a regular contributor to numerous medical publications, including Medscape Medical News and WebMD, and is the author of several consumer-oriented health books, as well as Behind the Burqa: Our Lives in Afghanistan and How We Escaped to Freedom (the memoir of two brave Afghan sisters who told her their story).