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Study breakdown

Bulevirtide: How a Peptide Entry Blocker Fights the World's Worst Hepatitis Virus

Randomized Controlled TrialModerate High evidence
The takeaway

The peptide drug bulevirtide reduced hepatitis D virus levels in up to 77% of patients at its highest dose, establishing it as the first targeted therapy for this severe liver infection.

77% response rate at 10 mg dose

Bulevirtide achieved a ≥2 log decline or undetectable HDV RNA in 77% of patients at the highest dose, versus just 3% with standard antiviral therapy alone.

What the researchers found

Bulevirtide, a first-in-class peptide entry inhibitor, significantly reduced hepatitis D virus (HDV) RNA levels when combined with tenofovir over 24 weeks. At the primary endpoint, 54% of patients on 2 mg bulevirtide, 50% on 5 mg, and 77% on 10 mg achieved either undetectable HDV RNA or a ≥2 log decline, compared to only 3% on tenofovir alone.

The 10 mg dose showed the strongest antiviral activity with a median 2.03 log10 decline in HDV RNA. However, HDV RNA rebounded after stopping bulevirtide, indicating the need for longer treatment. The drug was generally well tolerated, with asymptomatic bile salt increases being the most common side effect. No treatment-related deaths occurred.

Why it matters

Hepatitis D is the most severe form of viral hepatitis, affecting an estimated 12–72 million people worldwide, and until bulevirtide there was no approved targeted therapy. This trial provided key Phase 2 evidence supporting the conditional European approval of bulevirtide — the first peptide-based viral entry inhibitor for any hepatitis virus. It represents a completely new therapeutic approach: blocking the virus from entering liver cells rather than targeting viral replication.

The numbers in context

n=120 · 3 dose groups + control · 10 mg: 77% response · 2 mg: 54% response · TDF alone: 3% response · Median HDV RNA decline: 2.03 log10 (10 mg) · 24-week treatment

How the study worked

Multicentre, randomised, open-label, parallel-group Phase 2 trial (MYR202) across 16 hospitals in Germany and Russia. 120 adults with chronic hepatitis D (including 59 with cirrhosis) were randomized 1:1:1:1 to receive bulevirtide at 2 mg, 5 mg, or 10 mg subcutaneously daily plus oral tenofovir, or tenofovir alone, for 24 weeks. HDV RNA was monitored through week 48.

Who was studied

Adults aged 18-65 with chronic hepatitis D virus infection, including patients with cirrhosis and those who failed or had contraindications to PegIFNα

What this study cannot tell us

Open-label design means neither patients nor doctors were blinded, which could introduce bias. The sample size of 120 patients is moderate for a Phase 2 trial. HDV RNA rebounded after treatment cessation, so durability of response with longer treatment is unknown. The study did not assess functional cure (HDV RNA clearance sustained off-treatment).

How to read the evidence

This is a Phase 2 randomized controlled trial published in The Lancet Infectious Diseases with 120 patients. While the open-label design is a limitation, the randomization, clear dose-response relationship, and large effect size versus control provide moderately strong evidence.

When this study was published

Published in 2023 with data from a 2016 trial. Bulevirtide has since received conditional European approval and continues in Phase 3 studies. The findings remain highly relevant to current hepatitis D treatment.

The bigger picture

Bulevirtide represents a paradigm shift in hepatitis D treatment — it's the first drug to block viral entry into liver cells rather than targeting replication. This trial was instrumental in bulevirtide receiving conditional approval in Europe in 2020, and ongoing studies are evaluating longer treatment durations and combination approaches that could potentially cure hepatitis D.

Questions still open

  • Can longer treatment durations with bulevirtide achieve sustained viral clearance after stopping therapy?
  • Would combining bulevirtide with pegylated interferon lead to higher functional cure rates?
  • Could the entry-inhibitor approach used by bulevirtide be adapted for other hepatitis viruses?

Common questions

What is bulevirtide and how does it treat hepatitis D?
Bulevirtide is a peptide drug that blocks hepatitis B and D viruses from entering liver cells. It's the first therapy specifically designed to target hepatitis D by acting as an entry inhibitor. In this trial, daily injections reduced virus levels in up to 77% of patients over 24 weeks.
Is bulevirtide a cure for hepatitis D?
Not yet — in this trial, virus levels rebounded after stopping treatment, suggesting ongoing therapy is needed. Researchers are now studying longer treatment durations and combination approaches that might achieve sustained viral clearance. Bulevirtide is conditionally approved in Europe under the brand name Hepcludex.

Read the original research

Safety and efficacy of bulevirtide in combination with tenofovir disoproxil fumarate in patients with hepatitis B virus and hepatitis D virus coinfection (MYR202): a multicentre, randomised, parallel-group, open-label, phase 2 trial.

The Lancet. Infectious diseases, 23(1), 117-129

Citation

Wedemeyer, Heiner; Schöneweis, Katrin; Bogomolov, Pavel; Blank, Antje; Voronkova, Natalia; Stepanova, Tatiana; Sagalova, Olga; Chulanov, Vladimir; Osipenko, Marina; Morozov, Viacheslav; Geyvandova, Natalia; Sleptsova, Snezhana; Bakulin, Igor G; Khaertynova, Ilsiyar; Rusanova, Marina; Pathil, Anita; Merle, Uta; Bremer, Birgit; Allweiss, Lena; Lempp, Florian A; Port, Kerstin; Haag, Mathias; Schwab, Matthias; Zur Wiesch, Julian Schulze; Cornberg, Markus; Haefeli, Walter E; Dandri, Maura; Alexandrov, Alexander; Urban, Stephan. (2023). Safety and efficacy of bulevirtide in combination with tenofovir disoproxil fumarate in patients with hepatitis B virus and hepatitis D virus coinfection (MYR202): a multicentre, randomised, parallel-group, open-label, phase 2 trial.. The Lancet. Infectious diseases, 23(1), 117-129. https://doi.org/10.1016/S1473-3099(22)00318-8