During the study, some people will receive brelovitug while others will have their treatment delayed. All people taking part will also need to take one of the following medicines for hepatitis B: tenofovir disoproxil fumarate, tenofovir alafenamide fumarate, or entecavir. The study will measure whether the virus levels in the blood decrease by a certain amount or become undetectable, and whether liver enzyme levels return to normal. Liver enzyme is a substance in the blood that shows how well the liver is working, and when it is high, it can mean the liver is inflamed or damaged.

The study will also look at the safety of the treatment by checking for any unwanted effects and how many people need to stop treatment because of these effects. Other measurements will include checking liver stiffness, which shows how much scarring has occurred in the liver, and various scores that help doctors understand how well the liver is functioning. These checks will happen at different times during the study, including at weeks 24, 48, and 96 of treatment. The study is expected to last until early 2028.

The study has two parts. In Part A, healthy volunteers will receive a single dose of GS-4321 given either as an injection under the skin or into a vein. This part will help researchers understand how the medication moves through the body and whether it causes any unwanted effects. In Part B, people who have chronic hepatitis delta infection will receive multiple doses of GS-4321 over time. These participants must already be taking certain medications for hepatitis B, such as entecavir, tenofovir alafenamide, or tenofovir disoproxil fumarate. Researchers will check the virus levels in the blood and monitor liver function through blood tests and measurements of liver stiffness using a special imaging method called elastography.

Throughout the study, participants will have regular visits where blood samples will be taken to measure virus levels, check how the liver is working, and look for any side effects. The study will also check whether participants develop immune responses to the medication by looking for antidrug antibodies in the blood. For those in Part B, the treatment period will last up to 96 weeks, with regular monitoring to see how well the medication works in reducing virus levels and improving liver health markers such as alanine aminotransferase, which is a substance in the blood that can indicate liver inflammation.

Participants entering this study must already be taking bulevirtide for at least 6 months for their chronic hepatitis D infection. They will also need to be taking one of the following medications for hepatitis B and continue taking it throughout the study: TDF, TAF, or ETV. During the study, participants will switch from their current bulevirtide treatment to receiving BJT-778 injections under the skin. The study will measure how many participants have the hepatitis D virus become undetectable in their blood after switching to the new treatment.

The study will also look at safety by tracking any unwanted effects that occur during treatment, how many participants stop treatment because of unwanted effects, and changes in bile salts in the blood. Other measurements will include how many participants have their virus levels drop significantly or become undetectable at different time points, whether liver enzyme levels called ALT return to normal, and whether the virus remains undetectable after treatment ends. The treatment period can last up to 96 weeks, with additional follow-up visits after treatment is completed.

During the study, participants will receive either brelovitug or bulevirtide. Participants will continue taking their current hepatitis B medication (either tenofovir disoproxil fumarate, tenofovir alafenamide fumarate, or entecavir) throughout the trial. The researchers will monitor participants’ HDV RNA (the genetic material of the hepatitis D virus in the blood) and ALT levels (a liver enzyme that, when elevated, indicates liver damage). The study will also track changes in liver stiffness (a measure of liver scarring) and assess participants’ quality of life and fatigue levels during treatment.

The study will last 96 weeks (approximately 2 years), with the main comparison between the two treatments occurring at the 48-week mark. Researchers will evaluate whether the treatments can make the virus undetectable in the blood and normalize liver enzyme levels, indicating improved liver function. They will also monitor for any side effects or adverse events throughout the study period.

The purpose of the study is to assess the effectiveness of BJT-778 in treating Chronic Hepatitis Delta Infection over a period of time. Participants in the study will receive either the medication or a delayed treatment and will be monitored to see how their condition changes. The study will look at various outcomes, including changes in the levels of the virus in the body and improvements in liver function.

The trial will take place over several weeks, with participants being checked at different points to see how they are responding to the treatment. The study aims to provide valuable information on whether BJT-778 can be an effective treatment option for people with Chronic Hepatitis Delta Infection.

The purpose of this study is to evaluate how well the combination of Tobevibart and Elebsiran works compared to Bulevirtide in reducing the amount of virus in the body and to assess the safety of these treatments. Participants in the study will receive either the combination therapy or Bulevirtide and will be monitored over a period of time to see how their condition changes. The study will also look at how the treatments affect the liver and overall health of the participants.

Participants will receive the treatments through subcutaneous injections, which means the medication is injected under the skin. The study will take place over several weeks, with regular check-ups to monitor the participants’ health and the effectiveness of the treatments. The goal is to find out which treatment is more effective in managing Chronic Hepatitis D Virus (HDV) Infection and to ensure that the treatments are safe for the participants.

The purpose of the study is to evaluate how well the combination of Tobevibart and Elebsiran works in reducing the virus in the body. Participants in the study will receive these treatments through injections under the skin. The study will be conducted over a period of time, with regular check-ups to monitor the effects of the treatment. The study will also look at how the treatment affects liver health and any side effects that may occur.

Participants will be monitored for changes in their health, including the amount of virus in their blood and the condition of their liver. The study aims to provide valuable information on the effectiveness and safety of the combination therapy for people with Chronic Hepatitis D Virus Infection who have not responded well to previous treatments.

The purpose of this study is to assess how effective and safe the combination of Tobevibart and Elebsiran is for people with chronic HDV infection. Participants in the study will receive these medications through injections under the skin. The study will compare the effects of starting the treatment immediately versus delaying it. Throughout the study, participants will have regular check-ups to monitor their health and the virus’s response to the treatment.

The study will last for several years, with participants being observed at different intervals to see how the treatment affects the virus and their liver health over time. The goal is to see if the combination of Tobevibart and Elebsiran can reduce the amount of virus in the body and improve liver function. Participants will be closely monitored for any side effects or changes in their condition during the study period.

The purpose of the study is to assess how effective and safe these treatments are for people with chronic HDV infection. Participants will receive the treatments through injections under the skin. The study will monitor the participants over a period of time to observe any changes in their health and to check for any side effects. The study aims to see if the treatments can reduce the amount of virus in the body and improve liver function.

Throughout the study, participants will have regular check-ups to track their progress. The study will look at how the treatments affect the virus levels and liver health at different points in time. This research is important for understanding how these new therapies might help people with chronic HDV infection in the future.

The purpose of the study is to evaluate the effectiveness and safety of the treatment combination. Participants in the study will receive either the new treatment with the nucleos(t)ide analog or a placebo. The study will be conducted over a period of time, during which participants will be monitored for changes in their health and the levels of the viruses in their bodies. The study aims to see if the combination treatment can reduce the amount of the Hepatitis D virus in the body and improve liver health.

Throughout the study, participants will have regular check-ups and tests to track their progress. The study is designed to provide valuable information about the potential benefits of the new treatment for people with these viral infections. The results will help determine if this combination of medications can be a safe and effective option for managing Hepatitis B and Hepatitis D co-infections.

The study will take place over a period of time, during which participants will receive regular injections and attend follow-up visits. The trial will also include a medication called Vemlidy, which is a tablet taken by mouth and is already used to treat certain viral infections. Throughout the study, participants will be monitored for any changes in their health, including their liver function and the levels of the virus in their blood.

Participants will be asked to attend regular appointments to check their health and the effects of the treatment. The study aims to see if RBD1016 can reduce the amount of the virus in the body and improve liver health. The trial will also look at how the body processes the treatment and whether it causes any side effects. The results will help determine if RBD1016 could be a new option for treating chronic hepatitis D virus infection.

Participants in the study will receive Bulevirtide over a period of time, and researchers will monitor them for any liver-related events, such as liver failure, liver cancer, or the need for a liver transplant. The study will also track the percentage of participants who develop cirrhosis, a condition where the liver becomes severely scarred, and any serious side effects that may occur during the treatment.

The study aims to provide valuable information on how Bulevirtide affects the health of people with chronic hepatitis D over an extended period. This information could help improve treatment options for those living with this condition. Participants will be observed for up to 144 weeks to gather comprehensive data on the treatment’s impact.

Participants in the study will receive Bulevirtide and will be monitored over a period of time to observe their response to the treatment. The study will track the levels of the virus in the blood and other health markers to determine how well the treatment works. Some participants may receive a placebo, which is a substance with no active medication, to compare the effects of Bulevirtide. The study aims to see if the virus levels become undetectable in the blood after treatment and to monitor any changes in liver health and overall well-being.

The study will involve regular check-ups and tests to ensure the safety of the participants and to gather data on the treatment’s impact. The results will help understand the potential benefits and risks of using Bulevirtide for treating chronic hepatitis D. This information could be valuable for developing future treatment options for this condition.

The study will begin with healthy volunteers to assess the initial safety of BJT-778. Following this, individuals with Chronic Hepatitis B and Chronic Hepatitis D will participate to further evaluate the treatment’s effects. Participants will receive injections and be monitored for any side effects or changes in their health. The study will also measure how the body processes the drug and its impact on the viruses causing the infections.

Throughout the study, researchers will collect data on the participants’ health and any changes in their condition. This information will help determine the potential benefits and risks of BJT-778 for treating these chronic liver infections. The study is expected to continue until early 2025, providing valuable insights into the treatment’s effectiveness and safety.