The most aggressive form of viral hepatitis has no FDA-approved oral treatment in the United States. That may change. The FDA has accepted a new drug application for lonafarnib for chronic hepatitis D, moving an investigational oral therapy into formal review for a disease that most Americans, including many who are at risk, have never heard of.
EIT Pharma announced its acceptance in a statement this week. Acceptance means the agency has determined the application is complete enough to review. It is not an approval, and the company did not disclose a target action date.
"FDA acceptance of our NDA is an important milestone in our mission to bring a potential new oral treatment to people living with chronic hepatitis D," said Leen Kawas, PhD, the company's chief executive officer.
For the specific group of people living with this infection, the news is meaningful. For everyone else, the more useful takeaway concerns who should be tested and why.
The Virus That Cannot Survive Alone
Hepatitis D is unlike the other hepatitis viruses in a way that determines everything about how it spreads and who gets it. It is an incomplete virus. It cannot replicate on its own and requires the hepatitis B virus to provide the outer envelope it needs to enter liver cells.
That dependency creates two infection scenarios. A person can acquire both viruses simultaneously, a condition called coinfection. Or a person already living with chronic hepatitis B can later acquire hepatitis D, called superinfection, which carries a higher risk of progressing to chronic disease.
The clinical consequence of that dependency is severity. Hepatitis D accelerates liver damage relative to hepatitis B alone, and chronic infection can progress comparatively rapidly to cirrhosis, liver failure, and liver cancer.
The dependency also provides the most important preventive factor in this story. The hepatitis B vaccine prevents hepatitis D, because a person who never acquires hepatitis B cannot acquire hepatitis D. No separate vaccine exists or is needed.
The Testing Gap That Leaves People Undiagnosed
Hepatitis D is substantially underdiagnosed, and the reason is structural rather than technical.
Hepatitis B screening does not automatically include hepatitis D testing. A person can be diagnosed with chronic hepatitis B, enter routine monitoring, and never be tested for the virus that is accelerating their liver damage, unless a clinician specifically orders it.
Anyone living with chronic hepatitis B has a reason to ask whether they have been tested for hepatitis D. The question is simple, and the answer is in the chart. Risk is higher among people from regions where hepatitis D is more prevalent, people who have injected drugs, and those with other percutaneous or sexual exposure risks.
Awareness among clinicians has improved but remains uneven, which is why patient-initiated questions matter here more than in most conditions.
The Evidence Behind the Application
The application rests primarily on D-LIVR, described by the company as the largest clinical trial conducted to date in this disease. It was a global, randomized, placebo-controlled Phase 3 trial enrolling more than 400 patients across 21 countries and evaluating lonafarnib-based regimens over 48 weeks. The regimens studied combined lonafarnib with ritonavir, with or without peginterferon, rather than lonafarnib alone.
Lonafarnib works differently from antiviral drugs that target viral replication machinery. It is an oral farnesyltransferase inhibitor, blocking a host cell process the virus depends on to assemble itself. The drug previously received breakthrough therapy, fast track and orphan drug designations from the FDA for this indication, and the company has presented extended analyses from the trial at a European liver conference this year.
Several things have not been disclosed. As HCPLive reported, the company did not announce an FDA action date, whether an advisory committee review is planned, the proposed treatment regimen, or the labeling it has requested.
Detailed efficacy results were not restated in the acceptance announcement, and readers should not infer the magnitude of benefit from the fact of acceptance. The FDA reviews complete applications, including those it ultimately declines to approve.
The program has a complicated history. It was developed at Eiger BioPharmaceuticals, and EIT Pharma acquired the late-stage program in 2024 after Eiger encountered setbacks with other assets in the same disease area. A drug changing hands mid-development is not unusual and says little on its own about the underlying evidence, but it does mean the sponsor reviewing the data with regulators is not the sponsor that generated most of it.
Practical Steps for Patients and Families
Nothing available today changes as a result of this acceptance. Current management of chronic hepatitis D in the United States typically involves specialist care and, in some cases, off-label or interferon-based approaches; those decisions are made by a hepatologist or infectious disease specialist.
The actionable item for most readers is vaccination status. The hepatitis B vaccine is recommended for adults and is the only prevention that matters here. Anyone unsure whether they were vaccinated can ask a clinician about testing and catch-up vaccination.
People living with chronic hepatitis B should ask two questions at their next visit: whether they have been tested for hepatitis D, and whether they are current on liver cancer surveillance imaging, which is recommended for many patients with chronic hepatitis B regardless of hepatitis D status.
Anyone with a hepatitis D diagnosis can ask their specialist whether clinical trials are open to them and whether their case should be evaluated at a center with experience in the disease. If lonafarnib is eventually approved, the company argues that oral administration and room-temperature storage would offer practical advantages over some current approaches, though coverage and cost would be separate questions entirely.
Alcohol avoidance and hepatitis A vaccination are standard recommendations for people with chronic liver disease. Nobody should stop or change antiviral therapy based on news of a drug under review.
The FDA has not announced a decision date. MedicalDaily will report the action date if disclosed, any advisory committee scheduling, and the outcome of the review.
Key Questions Answered
What happened? The FDA accepted EIT Pharma's new drug application for lonafarnib to treat chronic hepatitis D. Acceptance means the application is complete enough for review, not that the drug is approved.
Why is hepatitis D different? It cannot replicate without the hepatitis B virus, which provides the envelope it needs to enter liver cells. It accelerates liver damage and can progress to cirrhosis, liver failure, and liver cancer.
Is there a vaccine? Not a separate one. The hepatitis B vaccine prevents hepatitis D, because a person who does not acquire hepatitis B cannot acquire hepatitis D.
Who should be tested? People living with chronic hepatitis B, particularly those from regions where hepatitis D is more prevalent or with injection drug use or other exposure risk. Hepatitis B screening does not automatically include hepatitis D testing.
What evidence supports the application? Primarily D-LIVR, a global randomized placebo-controlled Phase 3 trial enrolling more than 400 patients across 21 countries over 48 weeks, studying lonafarnib with ritonavir, with or without peginterferon.
When could it be available? Unknown. The company did not disclose an FDA action date, whether an advisory committee is planned, or the proposed regimen.
What should patients do now? Confirm hepatitis B vaccination status; ask about hepatitis D testing if living with chronic hepatitis B; maintain liver cancer surveillance; and continue current treatment without changes.
