RecruitingPhase IIIInterventional

A clinical study to investigate the safety and tolerability of efimosfermin alfa injection in participants with known or suspected F2- or F3-stage metabolic dysfunction-associated steatohepatitis (BOS-580-302)

Metabolic dysfunction-associated steatohepatitis (MASH) occurs when excess fat builds up in the liver, causing swelling, inflammation, and scarring over time. If left untreated, this scarring can lead to long-term liver damage. This clinical study is testing an experimental medicine called efimosfermin alfa. Researchers want to find out if it is safe and easy to tolerate for adults who have moderate to advanced liver scarring caused by MASH. Participants will be placed into groups by chance. They will receive either the study medicine (at one of two dose levels) or a dummy treatment (placebo) as an injection once every four weeks for one year. Taking part lasts about 60 weeks in total, including regular health checks. While taking part may not directly cure your liver condition, the results could help doctors find much-needed new treatments for people living with MASH.

At a glance

Status

Recruiting

Phase

Phase III

Sponsor

GlaxoSmithKline (United Kingdom)

Enrolment target

1,250

Start

24 Oct 2025

Estimated completion

23 Apr 2027

Metabolic dysfunction-associated steatohepatitis (MASH)

What is this study about?

Many people have extra fat in their liver without realising it. In some people, this fat causes irritation and swelling, leading to a condition called MASH (metabolic dysfunction-associated steatohepatitis). Over time, ongoing swelling creates patches of scar tissue in the liver, known as fibrosis. When this scarring reaches stages doctors call F2 or F3, the liver is under significant stress and needs extra care to prevent permanent damage.

At present, there are very few approved treatments that directly tackle this liver swelling and scarring. This study is testing a new injection medicine called efimosfermin alfa. It is designed to act like a natural signal in the body that helps reduce liver fat, ease swelling, and potentially slow down or reverse scar tissue build-up.

Because this is a Phase III trial, doctors are checking how safe the medicine is across a wider group of patients over a full year. By comparing different doses against an inactive dummy treatment (a placebo), researchers hope to learn whether this treatment can protect the liver and improve the quality of life for people living with MASH in the future.

Key takeaways

Tests a new monthly injection designed to reduce liver swelling and scarring in people with MASH.
Open to adults aged 18 to 75 with moderate liver scarring (stages F2 or F3).
Involves receiving an injection once every four weeks for one year.
Participants will be randomly assigned to receive the study drug or a dummy injection (placebo).
You will receive thorough, regular health check-ups and can leave the trial at any point.

Who may be eligible?

This trial is open to adults aged between 18 and 75 who have known or suspected MASH with moderate liver scarring (stages F2 or F3). Participants should also have traits linked to metabolic health, such as carrying extra weight, having high blood pressure, or having elevated blood sugar.

You will not be able to join if you have other types of liver conditions, such as viral hepatitis (including Hepatitis B or C) or liver damage caused by alcohol. People with very severe liver damage, serious kidney problems, low blood platelets, or poorly controlled diabetes are also excluded to ensure participant safety.

The research team will carry out detailed blood tests, scans, and physical checks during a screening period to confirm whether it is completely safe for you to take part.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

I am aged between 18 and 75.
I have been diagnosed with or am suspected of having MASH (fatty liver inflammation).
I have signs of metabolic health factors, such as high blood pressure, raised cholesterol, or high blood sugar.
I do not have viral hepatitis or liver disease caused by heavy alcohol use.
I am able to attend clinic visits and receive monthly injections for roughly one year.

Answer every question to see your result.

What does participation involve?

Taking part in the trial lasts around 60 weeks in total. It begins with a screening period lasting up to 8 weeks to make sure the study is a safe fit for you. If you qualify, you will be randomly assigned to receive either efimosfermin alfa (at a 225 mg or 300 mg dose) or a placebo. You will have a single injection under your skin once every 4 weeks for 52 weeks (one year). During this time, you will visit the hospital clinic regularly for health reviews, blood tests, and scans to monitor your liver and general health. After your final injection, there will be one last safety follow-up visit at week 56.

Potential risks and benefits

Taking part might not improve your liver condition directly, but you will receive close, expert medical attention and regular health check-ups throughout the trial. Your participation will also help researchers discover better treatments for people with liver disease. The most common side effects seen with this medicine include mild nausea, vomiting, diarrhoea, and redness or soreness where the injection was given; these usually clear up quickly on their own. Less common risks include changes in liver blood test levels, gallbladder inflammation, or rare allergic reactions. Taking part is entirely voluntary, and you are free to stop at any time without your normal NHS care being affected in any way.

Locations (4)

Kings College Hospital
Approximate
London, England
University Hospital Aintree
Approximate
Liverpool, England
The Royal London Hospital
Approximate
London, England
Chelsea and Westminster Hospital
Approximate
London, England

Common questions

What is a placebo and why is it used?

A placebo looks just like the real medicine but contains no active ingredients. It helps researchers clearly see whether any improvements or side effects are truly caused by the study drug.

Will I know if I am getting the real drug or the dummy injection?

No. This is a double-blind trial, which means neither you nor the study doctors will know which treatment you are receiving until the study is over, ensuring completely unbiased results.

How is the study medicine given?

The medicine is given as a simple injection just under the skin once every four weeks during your scheduled clinic visits.

Do I have to pay to take part in this trial?

No, all study medications, doctor visits, and medical tests are provided free of charge, and travel costs can usually be reimbursed.

Can I continue seeing my regular GP during the trial?

Yes. You should continue seeing your GP as normal, and the trial team can keep your doctor updated about your health checks.

How to find out more

Sona Drezikova

sona.drezikova@iqvia.com +421 (0)911990036 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.