RecruitingPHASE1INTERVENTIONAL

Safety and Antiviral Activity of a Monoclonal Hepatitis B Antibody: a Phase 1b, Open-label Trial in Individuals With Chronic Hepatitis D Infection

This study is looking into a new treatment for chronic hepatitis D (HDV), a serious liver infection. HDV needs another virus, hepatitis B (HBV), to grow and spread in the body. Without HBV, HDV can't survive. Researchers have found an antibody called HepB mAb19 that can reduce the amount of HBV. They are hopeful that by targeting HBV with this new antibody, they can also help treat HDV. This is a small, early-stage study (Phase 1b) involving 15 people with chronic HDV. The main goals are to see if the antibody is safe, how the body handles it, and if it helps reduce the levels of HDV in the body. Participants will receive a few doses of the antibody and be carefully monitored for over a year.

At a glance

Status

Recruiting

Phase

PHASE1

Sponsor

Aarhus University Hospital

Enrolment target

Start

23 Apr 2026

Estimated completion

01 Apr 2028

Hepatitis D, Chronic Hepatitis B Chronic Infection

What is this study about?

Imagine two tiny viruses, Hepatitis B (HBV) and Hepatitis D (HDV), that can both cause serious liver problems. The trick with HDV is that it can't survive on its own; it always needs HBV to be present in the body to grow and spread. This makes HDV infection particularly tricky to treat and can unfortunately lead to very severe liver disease, including scarring of the liver (cirrhosis) and even liver cancer.

Currently, there aren't many good treatments for HDV, and they often can't completely get rid of the infection. That's why scientists are constantly looking for new ways to fight it. Researchers at Rockefeller University have discovered a special antibody, called HepB mAb19. An antibody is like a tiny, clever soldier made by the body (or in this case, in a lab) that can recognise and attack specific targets. This particular antibody is very good at reducing the amount of HBV in the body.

Because HDV relies completely on HBV to survive, the researchers have a promising idea: if they can significantly reduce HBV using HepB mAb19, it might also stop HDV from multiplying. This study is designed to test this idea. It's a small, early-stage study – called a Phase 1b trial – which means it's mainly focused on safety and getting a first look at whether the new treatment works. We'll be giving the antibody to 15 people with chronic HDV infection and carefully watching what happens.

Key takeaways

This is an early study testing a new antibody (HepB mAb19) for chronic hepatitis D (HDV).
HDV needs hepatitis B (HBV) to survive, so the antibody aims to reduce HBV levels.
The study will check the safety of the antibody and see if it helps reduce HDV levels.
It involves 15 participants, receiving a few antibody doses, and being monitored for over a year.
This research hopes to find new treatment options for HDV, which currently has limited cures.

Who may be eligible?

This study is looking for people aged 18 to 70 who have been diagnosed with chronic hepatitis D (HDV). This means your doctor will have confirmed the HDV infection with tests, and you won't have developed antibodies against HBV (meaning your body isn't fighting off HBV on its own in that way).

However, there are certain reasons why someone might not be able to join. For example, if you have severe or advanced liver disease, have had serious allergic reactions to similar medications before, are pregnant or breastfeeding, or have certain other serious health conditions like uncontrolled HIV or other active severe infections, you wouldn't be able to take part. Also, if you've recently had certain vaccinations or been part of another drug trial, you might need to wait.

Certain blood test results also need to be within a healthy range; for instance, very high levels of a specific liver marker (alpha fetoprotein) or very low levels of blood cells (like platelets or haemoglobin) might prevent participation. It's important to discuss all your medical history with the study team to see if this study is right for 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 between 18 and 70 years old?
Has your doctor confirmed you have chronic hepatitis D (HDV)?
Are you healthy enough, without severe liver damage or other serious conditions?
If you can become pregnant, are you willing to use two types of birth control?
Have you avoided other experimental drug studies or certain vaccinations recently?

Answer every question to see your result.

What does participation involve?

If you join this study, you will receive two or three doses of the HepB mAb19 antibody. These will be given as infusions, likely into a vein. After your first dose, you will be carefully followed for about 60 weeks, which is just over a year. During this time, you'll have several visits to the study clinic for check-ups. These visits will involve blood tests to see how your body is responding to the treatment, if the antibody levels are as expected, and to measure the levels of HDV and HBV in your body. The team will also monitor your general health closely to ensure the treatment is safe and to look for any side effects. You'll need to commit to these regular visits and tests throughout the study period.

Potential risks and benefits

Participating in this study might offer a potential benefit: you could be among the first to receive a new treatment that might help reduce your hepatitis D infection, which could lead to better liver health. However, as with any new medication, there are potential risks, including side effects that are not yet fully known. Since this is an early-stage study, the main goal is to find out more about the safety and how the antibody works, rather than directly treating your HDV. You will be closely monitored for any unwanted effects, and you have the right to withdraw from the study at any time, for any reason, without it affecting your medical care.

Locations (2)

Aarhus University Hospital
Verified postcode
Aarhus, Denmark· Recruiting
Charité - Universitätsmedizin Berlin
Verified postcode
Berlin, Germany· Not yet recruiting

Common questions

What is an antibody?

An antibody is like a special protein made by your immune system to find and fight off germs like viruses. In this study, the antibody used was made in a lab to specifically target the hepatitis B virus.

Why is this study focusing on hepatitis B if it's for hepatitis D?

Hepatitis D (HDV) can't survive without Hepatitis B (HBV). If we can reduce the amount of HBV, the hope is that it will also stop the HDV from growing and causing problems.

How will I receive the study medication?

The study medication, HepB mAb19, will be given to you as a drip (infusion) into a vein, similar to how some medicines are given in a hospital or clinic.

How long will I be in the study?

After your first dose of the antibody, you will be followed for about 60 weeks, which is a bit over a year. This includes regular clinic visits.

Can I leave the study at any time?

Yes, you are free to leave the study at any point and for any reason. Your decision will not affect your routine medical care.

How to find out more

Ole Schmeltz Søgaard, MD, PhD, professor

olesoega@rm.dk +45 24 77 79 95 Official trial record

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