Chronic hepatitis D is a serious liver infection caused by the hepatitis Delta virus (HDV). HDV cannot survive on its own. It depends on the hepatitis B virus (HBV) to infect liver cells and spread. Hence, people with hepatitis D also have hepatitis B. Over time, hepatitis D can lead to liver inflammation, scarring (cirrhosis), liver failure, or liver cancer.
Hepcludex (bulevirtide) is the first medicine approved by the FDA to treat chronic (long-term) hepatitis D infection. It is given as a daily injection under the skin.
This article covers how Hepcludex works to treat hepatitis D, how to use it, the benefits observed in clinical trials, and more.
How Does Hepcludex Work for Hepatitis D?
Viruses need to enter cells to make more copies of themselves. The hepatitis D virus (HDV) attaches to a specific entry point on the surface of liver cells called sodium taurocholate cotransporting polypeptide (NTCP). Hepcludex blocks this entry point so the virus cannot easily enter liver cells. This helps slow the spread of the infection through the liver.
Hepcludex does not kill HDV that is already inside infected liver cells, and it is not considered a cure for hepatitis D. Instead, it helps prevent the virus from spreading to new cells while the body gradually clears infected cells over time. With fewer liver cells getting infected, the amount of HDV in the body may drop over time. In some people, virus levels can become so low that blood tests cannot detect them.
To check how well treatment is working, health care providers measure HDV RNA levels during treatment. RNA is the genetic material of the virus, so HDV RNA levels indicate how much virus is in the body.
Because hepatitis D depends on hepatitis B, people using Hepcludex may also need treatment for hepatitis B and ongoing monitoring with blood tests and liver checkups.
How Do I Use Hepcludex?
Hepcludex is given once daily as an injection under the skin (subcutaneous injection). It is injected into the upper thigh or lower abdomen. A caregiver may also inject it into the back of the upper arm.
Hepcludex comes as a powder in a single-use vial that must be mixed with sterile water before use. Your health care provider can show you or a caregiver how to prepare and inject Hepcludex safely. The first dose may be given under medical supervision.
How Was Hepcludex Studied for Hepatitis D?
A trial called MYR301 was done to study Hepcludex in adults with long-term (chronic) hepatitis D infection who either did not have liver scarring (cirrhosis) or had compensated cirrhosis. Compensated cirrhosis means the liver has advanced scarring but can still mostly do its job.
Everyone in the study eventually received Hepcludex 8.5 mg once daily as an injection under the skin. The study followed people for up to 144 weeks of treatment and for an additional 96 weeks after treatment ended.
The study compared two groups:
- One group started Hepcludex right away and used it for 144 weeks (the “immediate-treatment group”).
- The second group waited 48 weeks before starting treatment (the “delayed-treatment group”). After the waiting period, they used Hepcludex for 96 weeks.
This trial included 100 adults. The average participant age was 41 years. About 55% were men, and the rest were women. Most participants were White (82%), 17% were Asian, and 1% were Black or African American. About half (48%) had compensated cirrhosis. More than half (57%) had previously received interferon treatment, and 59% were also taking antiviral medicines for hepatitis B during the study.
The main goal of the study was to see how many people met a combined treatment goal. To meet this goal, participants needed to have both:
- A significant drop in virus levels or undetectable HDV
- Normal levels of alanine transaminase (ALT), which is a liver enzyme that can rise when the liver is inflamed or damaged
What Were the Results?
The MYR301 trial results showed that many people using Hepcludex had lower hepatitis D virus levels and improved ALT levels during treatment.
Week 48 results
- 48% of people who started Hepcludex right away met the study’s combined goal of having both a significant drop in their virus levels or undetectable HDV and a normal ALT level after 48 weeks.
- Only 2% of people in the delayed-treatment group met this goal during the same period.
Researchers also looked separately at virus levels and liver enzyme results, as shown in the table below:
48 Week result | Immediate-treatment group (started Hepcludex right away) | Delayed-treatment group (waited 48 weeks before starting Hepcludex) |
|---|---|---|
| Significant drop in HDV levels or undetectable virus levels | 76% | 4% |
| ALT in normal range | 56% | 12% |
| Undetectable HDV | 20% | 0% |
Longer-term results
Many people continued to have low or undetectable HDV levels and normal ALT during longer-term Hepcludex treatment, as shown in the table below:
Longer-term result | Immediate treatment group | Delayed treatment group (after 96 weeks of treatment) | |
|---|---|---|---|
Week 96 | Week 144 | Week 144 | |
| Met the combined treatment goal | 56% | 54% | 56% |
| Significant drop in HDV levels or undetectable virus levels | 82% | 76% | 92% |
| ALT in normal range | 64% | 60% | 58% |
| Undetectable HDV | 36% | 50% | 52% |
Results after treatment stopped
The study also followed participants after they stopped using Hepcludex to see how long treatment responses lasted. While some people continued to have lower HDV levels and normal ALT levels after treatment ended, response rates generally decreased over time.
At 24 weeks after treatment ended:
- 32% of the immediate-treatment group still met the combined treatment goal.
- 20% of the delayed-treatment group still met the combined treatment goal.
- 26% of the immediate-treatment group and 18% of the delayed-treatment group still had undetectable HDV.
At 96 weeks after treatment ended:
- 24% of participants in both groups still met the combined treatment goal.
- 22% of the immediate-treatment group and 20% of the delayed-treatment group still had undetectable HDV.
Keep in mind that individual results can differ from those seen in studies, and not everyone responds to treatment in the same way.
Is Hepcludex FDA-Approved?
Hepcludex was approved in May 2026 through the FDA’s accelerated approval program. This program allows some medicines to become available sooner based on early study results.
Hepcludex was approved because studies showed that many people had lower HDV levels and improved liver enzyme tests (ALT levels) during treatment. Lower HDV levels may mean the infection is becoming less active, while lower ALT levels may suggest less liver inflammation or damage.
However, researchers still need to confirm that these improvements lead to clear long-term health benefits. Additional studies are ongoing, and continued FDA approval may depend on the results of those studies.
What Happens if You Stop Using Hepcludex?
Stopping Hepcludex may lead to a sudden worsening of hepatitis D and hepatitis B. This is called a “flare-up” or “exacerbation.” During a flare-up, the viruses can become more active again, which may increase liver inflammation and liver damage. The risk may be higher in people with cirrhosis (advanced liver scarring).
In severe cases, the liver may stop working properly. This is called hepatic decompensation. Symptoms can vary and include:
- Yellowing of the skin or eyes (jaundice)
- Swelling in the belly or legs
- Confusion or trouble thinking clearly
- Severe tiredness
- Dark urine
- Nausea or vomiting
- Easy bruising or bleeding
Do not stop using Hepcludex without talking to your health care provider first. If treatment is stopped, your health care provider will closely monitor your liver health and virus levels with blood tests and follow-up visits for at least six months. In some cases, you may need antiviral treatment.
Your health care provider will monitor your virus levels and liver health to help decide how long you should continue Hepcludex treatment.
How Can I Get Hepcludex? Is There Any Cost Assistance Available?
Hepcludex is available by prescription through a specialty pharmacy network rather than your local pharmacy. The drugmaker, Gilead, offers patient support programs that may help with insurance questions, copay costs, injection training, refill coordination, and medication delivery.
Eligible commercially insured patients may qualify for a copay savings program that can reduce out-of-pocket costs. For more information, visit this website or call 855-769-7284.
