In the last Talk with Dr. Block blog post, hepatitis B expert Timothy Block, Ph.D., co-founder, and President of the Hepatitis B Foundation, sat down to discuss the status of a hepatitis B cure and how the foundation is contributing to the cure efforts. In this second installment, he provides an inside look into what a cure could possibly look like and a potential cure timeline!
This is the final post in a two-part series.
We keep hearing that a combination of drugs will be necessary to cure HBV. What will these therapies look like?
A combination of drugs is likely not necessary for everyone. We already know that a small number of people who are treated with one drug can do fairly well. However, most people will likely need a combination of drugs only because of precision medicine. Precision medicine allows a healthcare specialist or provider to develop treatments on an individual scale based upon an understanding of that person’s response to the disease. Some patients might respond better to specific drugs and specific doses due to differences such as age or underlying health conditions. We should take advantage of precision medicine and match specific drugs with the specific clinical state that someone is in. I do not believe that an immunomodulator, or medications that help to regulate the immune system, will be necessary for most people. It may, however, accelerate a cure and help us create a cure cocktail that will be effective in a large number of patients.
A functional cure for hepatitis B will likely be defined as the absence of the hepatitis B virus in the cells. This means that the person will have a sustained loss of surface antigen (HBsAg negative) and undetectable viral load (HBV DNA). I look forward to a time where we have drugs that are both functionally and clinically curative. It is difficult to say if the cure will be in pill form, an injection, or an infusion. The hope is to eventually have a cure that will be taken orally for a short amount of time like the hepatitis C cure. More research needs to be done in order to truly determine what form the cure might take.
How long do you anticipate someone will need to be treated?
A person would likely need to be treated for a few years. I base this time frame on the lifespan of an infected cell and how long I think it would take to safely replace the infected cells with healthy, uninfected cells. However, it is important to remember that people with chronic hepatitis B differ by the number of infected cells they have in their liver; some people may have most of their liver infected while others might have a smaller portion of their liver infected. The replication of the virus in the body and immune response also differ from person to person. Due to these factors, treatment will likely be administered by some form of response-guided therapy (RGT). This type of treatment means that a doctor will monitor the patient as they take the medication and adjust it as needed. Some patients will respond rapidly to the drugs and will be able to end treatment sooner than others.
When can we anticipate a combination of therapies resulting in a cure?
I’m very optimistic. At the moment, it looks like we might see the approval of one to two new drugs for hepatitis B or hepatitis Delta between the next 18 months and 2 years. The approval of these potential drugs is dependent upon the research conducted in clinical trials, but there are several drugs set to enter Phase 3 of their trials, which is promising! I expect that entry inhibitors – antiretroviral drugs that block a virus from infecting a healthy cell – will be among the first round of new drugs to be approved by the Food and Drug Administration (FDA). It is difficult to say if they will be a cure, but they will likely be a big step in the right direction!
Disclaimer: The information provided in this article is based upon recent research and updates in the field. Please note that timelines and specific information regarding hepatitis B drugs are estimations and are subject to change as new research emerges.