AuthorisedTherapeutic confirmatory (Phase III)Interventional

A Phase 3, Randomized, Double-Blind, Placebo-Controlled, 3-Arm Study to Investigate the Safety and Efficacy of Efimosfermin Alfa in Participants With Biopsy-Confirmed F2- or F3-Stage Metabolic Dysfunction-Associated Steatohepatitis (MASH) (ZENITH-1)

This research study, called ZENITH-1, is looking into a new treatment called Efimosfermin alfa for people diagnosed with Metabolic Dysfunction-Associated Steatohepatitis (MASH). MASH is a liver condition that causes inflammation and scarring. The main aim is to find out if this new medicine can help improve liver scarring (fibrosis) and reduce the liver damage caused by MASH. Some participants will receive the new medicine, while others will get a placebo (a dummy treatment with no active ingredients). This will help doctors understand how effective and safe Efimosfermin alfa is in improving liver health and preventing serious liver problems over time. The study will last for a number of years, with regular check-ups to monitor progress.

At a glance

Status

Authorised

Phase

Therapeutic confirmatory (Phase III)

Sponsor

Glaxosmithkline Research & Development Limited

Enrolment target

Start

08 Jun 2026

Metabolic Dysfunction-Associated Steatohepatitis (MASH)

What is this study about?

This study, called ZENITH-1, is designed to test a new medicine, Efimosfermin alfa, for people with a liver condition called MASH (Metabolic Dysfunction-Associated Steatohepatitis). MASH is a serious type of fatty liver disease where there's inflammation and damage, which can lead to scarring (fibrosis) in the liver. This scarring can eventually become severe and cause serious health problems.

The main goal of this study is to see if Efimosfermin alfa can help reduce this liver scarring and improve the overall health of the liver. We also want to find out if it can help resolve the inflammation and fat build-up in the liver. To do this, some people in the study will receive the active medicine, while others will receive a placebo, which looks like the medicine but doesn't contain any active ingredients. This is a common way to test new medicines and helps us compare the effects fairly.

The researchers will closely monitor participants for a long time, checking how their liver changes and if the medicine helps prevent serious liver-related problems. They will also keep a close eye on any side effects to make sure the treatment is safe. By comparing the groups, we hope to understand if Efimosfermin alfa could be a new and effective treatment option for MASH.

Key takeaways

This study is testing a new medicine for MASH liver disease.
It aims to see if the medicine can improve liver scarring and damage.
Some participants will receive the medicine, others a dummy treatment (placebo).
It's a long-term study with regular health checks.
Participation includes medical examinations, blood tests, and liver biopsies.
You can stop participating at any time.

Who may be eligible?

To be considered for this study, you need to be an adult, aged 18 or older. Both men and women are welcome to take part.

You must have been diagnosed with MASH, and doctors will need to confirm this with a liver biopsy. This biopsy will also show that your liver scarring is at a moderate (F2) or more advanced (F3) stage. The study will have specific criteria about what other health conditions might prevent you from joining, which your doctor will discuss with you.

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.

Are you 18 years old or older?
Have you been diagnosed with MASH?
Has a doctor confirmed your MASH with a liver biopsy?
Has your biopsy shown moderate (F2) or more advanced (F3) liver scarring?

Answer every question to see your result.

What does participation involve?

If you join this study, you will be randomly assigned to one of three groups. One group will receive the new medicine, Efimosfermin alfa, and the other two groups will receive a placebo (a dummy treatment). Neither you nor your study doctor will know which treatment you are receiving until the end of the study. This is called 'double-blind' and helps ensure the results are fair.

You will have regular visits to the clinic over a number of years, initially for about a year (52 weeks) and then for extended follow-up (up to 4 years total). These visits will involve blood tests, physical examinations, and possibly imaging scans to check your liver health. A liver biopsy will also be taken at the start and potentially at other points to monitor changes in your liver scarring. You will also be asked about any side effects you might experience. All participants will be closely monitored throughout the study.

Potential risks and benefits

Taking part in any clinical study has potential benefits and risks. You might benefit from closer monitoring of your health than usual and could receive a new treatment that might improve your liver condition. However, there's no guarantee the treatment will work, and you might receive a placebo without active medicine. Potential risks could include side effects from the study medicine or discomfort from procedures like blood tests or liver biopsies. All known or expected side effects will be fully explained to you. Remember, your participation is completely voluntary, and you have the right to withdraw from the study at any time, for any reason, without it affecting your usual medical care.

Locations (2)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

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Unverified
Belgium
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Unverified
Greece

Common questions

What is MASH?

MASH stands for Metabolic Dysfunction-Associated Steatohepatitis. It's a type of liver disease where fat builds up in the liver, causing inflammation and damage, which can lead to scarring.

What is 'fibrosis'?

Fibrosis means scarring in the liver. When the liver is damaged, it can form scar tissue. Too much scarring can stop the liver from working properly.

What is a 'placebo'?

A placebo is a dummy treatment. It looks exactly like the real medicine but doesn't contain any active ingredients. It helps us see if the new medicine is truly effective.

How long will the study last?

The initial part of the study will last about 52 weeks (one year), but participants will be followed for a longer period, up to 48 months (four years).

Will I know if I'm getting the real medicine?

No, this is a 'double-blind' study, meaning neither you nor your study doctor will know whether you are receiving the active medicine or the placebo until the study ends.