Bulevirtide works, but a true cure is still rare
The most direct answer is yes: chronic hepatitis D is now treatable, but a cure remains uncommon. In the pivotal phase 3 trial, 45% of patients on 2 mg of bulevirtide and 48% on 10 mg achieved the primary endpoint—a combined response of undetectable or significantly reduced HDV RNA plus normal liver enzymes—after 48 weeks, compared to just 2% in the untreated control group [1]. That is a dramatic improvement over the historical standard of care, but it is not a cure: only 12% (2 mg) and 20% (10 mg) achieved undetectable HDV RNA, and no patient lost the hepatitis B surface antigen (HBsAg), which is the closest marker to a functional cure [1].
The gap between 'treatable' and 'cured' is important for patients to understand. Bulevirtide blocks the virus from entering liver cells, which suppresses viral replication and improves liver inflammation, but it does not eliminate the virus from the body [2]. In the phase 3 trial, the drug also normalized ALT (a liver enzyme) in about half of patients, and it was well tolerated—no treatment-related serious adverse events were reported [1]. So while it is not a cure, it is a meaningful treatment that can slow disease progression and improve liver health.
Combining bulevirtide with pegylated interferon improves the odds of undetectable virus
Adding pegylated interferon (PegIFN) to bulevirtide appears to boost the chance of clearing the virus, at least in the short term. In a phase 2 trial, 46% of patients on 10 mg bulevirtide plus PegIFN had undetectable HDV RNA 24 weeks after stopping treatment, compared to 12% on bulevirtide alone—a statistically significant difference [3]. Even the 2 mg combination achieved 32%, and PegIFN alone achieved 17% [3]. This suggests that combination therapy may offer a higher chance of a durable virologic response, though the trial was smaller and open-label, so results should be interpreted with caution.
The downside is that PegIFN is not easy to tolerate. The most common side effects in the combination trial were leukopenia, neutropenia, and thrombocytopenia—low blood counts—though most were mild to moderate [3]. In contrast, bulevirtide monotherapy is generally well tolerated, with side effects like headache, itching, and injection-site reactions [1]. So the choice between monotherapy and combination therapy involves a trade-off between efficacy and tolerability, and patients should discuss this with their hepatologist.
Real-world data confirm benefits, even in patients with advanced cirrhosis
Beyond clinical trials, real-world experience shows bulevirtide is effective and safe in everyday practice, including in patients with decompensated cirrhosis (liver failure) and after liver transplantation. In a Moscow cohort of 73 patients, 90% had cirrhosis, and 42% achieved aviremia (undetectable HDV RNA) while on treatment, with some responses appearing as late as 72–120 weeks [4]. In a smaller Novosibirsk series, 73% of 11 patients achieved a complete virologic response, including one with post-transplant recurrence [5]. These are not cures—most patients remained on therapy—but they show that even the sickest patients can benefit.
The most striking real-world evidence comes from a study of 14 patients with decompensated cirrhosis (Child-Pugh class B or C). After 48 weeks of bulevirtide, HDV RNA dropped from 6.1 to 3.6 log10, ALT normalized in most, and liver stiffness decreased from 20.8 to 18.6 kPa [6]. Importantly, liver function improved: the Child-Pugh score declined by 2 points on average, and the frequency of hepatic encephalopathy fell from 86% to 9% [6]. This is a major clinical benefit, because decompensated cirrhosis is a life-threatening condition. However, the study was small and uncontrolled, so these results need confirmation in larger studies.
About These Sources
This answer is built on 6 peer-reviewed studies — published from 2023 to 2026, 3 from 2024 or later, 3 in Q1 journals, collectively cited 337 times — selected as the most relevant from 10 studies that passed quality screening, drawn from 55 papers retrieved from a database of over 500 million.
Sources used in this answer
A Phase 3, Randomized Trial of Bulevirtide in Chronic Hepatitis D
In a phase 3 randomized trial, bulevirtide at 2 mg or 10 mg daily achieved the combined primary endpoint (undetectable or ≥2 log10 drop in HDV RNA plus ALT normalization) in 45% and 48% of patients, respectively, versus 2% in controls, but undetectable HDV RNA was only 12% and 20%.
Hepatitis D
A review in JAMA summarizes that HDV affects 12–72 million people worldwide, causes more rapid progression to cirrhosis than HBV alone, and notes that bulevirtide was recently approved in Europe, while pegylated interferon remains the only treatment in most countries.
Bulevirtide Combined with Pegylated Interferon for Chronic Hepatitis D
In a phase 2b open-label trial, 10 mg bulevirtide plus peginterferon alfa-2a led to undetectable HDV RNA in 46% of patients 24 weeks after treatment end, versus 12% with bulevirtide monotherapy (p<0.001).
Treatment of chronic hepatitis D – real-world experience in Moscow
In a real-world Moscow cohort of 73 patients (90% with cirrhosis), bulevirtide monotherapy or combination therapy achieved aviremia in 42% of patients, with good tolerability and no serious adverse events.
Experience with antiviral therapy for chronic hepatitis D in Novosibirsk
In a real-world Novosibirsk cohort of 11 patients, 73% achieved complete virologic response (undetectable HDV RNA) on bulevirtide, including one with post-transplant recurrence, with no severe adverse events.
Antiviral therapy experience in patients with chronic hepatitis D and decompensated cirrhosis
In a study of 14 patients with decompensated cirrhosis, bulevirtide 2 mg for 48 weeks reduced HDV RNA from 6.1 to 3.6 log10, improved liver function (Child-Pugh score down by 2 points), and reduced hepatic encephalopathy from 86% to 9%.