FDA Approves Bulevirtide for Hepatitis D Treatment

FDA Approves Bulevirtide for Chronic Hepatitis D Treatment

The U.S. Food and Drug Administration (FDA) has approved bulevirtide-gmdo (Hepcludex) injection for the treatment of chronic hepatitis D virus (HDV) infection in adults with compensated cirrhosis.

This approval marks a significant milestone for patients with HDV, a severe and potentially life-threatening liver disease that can accelerate progression to fibrosis, cirrhosis, liver cancer, liver failure, and death.

HDV infection occurs only in individuals who are also infected with hepatitis B virus (HBV). Transmission risks include unprotected sexual contact, injection drug use, and occupational exposure to blood. HBV vaccination remains the primary preventive measure against both HBV and HDV infection.

Study Findings

The FDA approval was supported by results from the Phase 3 MYR301 trial, a multicenter, randomized, open-label, parallel-arm study evaluating bulevirtide in adults with chronic HDV infection.

In the trial, participants were randomized to receive either immediate treatment with bulevirtide 8.5 mg once daily for 144 weeks or delayed treatment following a 48-week observational period, after which patients received bulevirtide 8.5 mg daily for 96 weeks.

The primary efficacy endpoint was a combined response at Week 48, defined as both undetectable HDV RNA—measured using a sensitive assay with a lower limit of quantification of 50 IU/mL—or at least a 2 log10 IU/mL reduction from baseline, together with normalization of alanine aminotransferase (ALT) levels.

Results demonstrated a combined response rate of 48% in the bulevirtide group compared with 2% in the delayed-treatment group. At Week 48, 20% of treated patients achieved undetectable HDV RNA, while no patients in the delayed-treatment arm reached this endpoint. Rates of undetectable HDV RNA increased over time, reaching 36% at Week 96 and 50% at Week 144 among patients receiving bulevirtide.

The safety profile was generally consistent with previous studies. Reported adverse events included hypersensitivity reactions, injection-site reactions, headache, abdominal pain, fatigue, and pruritus. The prescribing information includes a boxed warning highlighting the risk of severe acute exacerbations of HDV infection following discontinuation of therapy.

Clinical Implications

Historically, treatment options for HDV have been limited, and patients often face a high risk of progressive liver disease despite management of underlying HBV infection. For clinicians, the availability of bulevirtide introduces a targeted antiviral therapy capable of achieving meaningful reductions in viral replication while improving biochemical markers of liver inflammation. The increasing rates of undetectable HDV RNA observed through 144 weeks suggest that sustained treatment may enhance virologic outcomes over time.

Health care professionals should remain vigilant regarding treatment discontinuation, given the potential for severe HDV flares. Careful monitoring of liver function and viral activity may be warranted when therapy is interrupted or stopped.

Supported by Phase 3 evidence demonstrating significant virologic and biochemical responses, the therapy offers a new treatment option for patients with a disease that has long lacked effective approved therapies.

Reference:

FDA approves first treatment for chronic hepatitis delta virus (HDV) infection. News release. US Food and Drug Administration; May 22, 2026. Accessed May 29, 2026. https://www.fda.gov/news-events/press-announcements/fda-approves-first-treatment-chronic-hepatitis-delta-virus-hdv-infection?utm_medium=email