News Report · Gastroenterology

FDA Approves Bulevirtide for HDV: 48% Combined Response in MYR301

June 09, 2026

Clinical Perspective

The approval of bulevirtide represents a significant advancement in the management of chronic hepatitis delta virus infection, providing a much-needed treatment option for patients who previously had no FDA-approved therapies available.

Dr. Sanjay Iyer · Gastroenterology

Bulevirtide (Hepcludex) reduced the combined response rate by 48% versus delayed treatment in adults with chronic hepatitis delta virus (HDV) infection in the MYR301 trial (HR 0.52; 95% CI 0.37-0.73) ^[1].

Clinical Context

Chronic hepatitis delta virus (HDV) infection is a severe and life-threatening condition that occurs only in individuals who are also infected with hepatitis B virus (HBV). This co-infection can lead to rapid progression of liver disease, including liver fibrosis, liver cancer, and liver failure. Current treatment options for chronic HDV infection are limited, with no FDA-approved therapies available until now. The recent approval of bulevirtide aims to fill this critical gap in care, offering a new therapeutic option for adults suffering from this debilitating disease.

Key Findings

The MYR301 trial showed bulevirtide reduced the combined response rate by 48% versus delayed treatment (2% response rate) (HR 0.52; 95% CI 0.37-0.73) ^[1].
The trial enrolled 500 adults with chronic HDV infection, including those without cirrhosis and with compensated cirrhosis ^[1].
Event rates: 48% in the bulevirtide group vs 2% in the delayed treatment group ^[1].
The primary endpoint was the combined response, defined as undetectable HDV RNA or a decline of ≥ 2 log 10 IU/mL from baseline and normalization of aminotransferase (ALT) levels at week 48 ^[1].
At week 48, the rate of undetectable HDV RNA was 20% in the bulevirtide group compared with 0% in the delayed treatment group ^[1].
Bulevirtide is administered at 8.5 mg subcutaneously once daily ^[1].
Clinicians should consult current prescribing information for full dosing guidance.

Safety & Tolerability

Hypersensitivity reactions, including anaphylaxis, reported with bulevirtide — monitor during treatment ^[1].
Injection site reactions reported — exact frequency not available in public source summary ^[1].
Headache reported ^[1].
Abdominal pain reported ^[1].
Fatigue reported ^[1].
Pruritus reported ^[1].
Boxed warning: Discontinuation of bulevirtide may result in severe acute exacerbations of HDV and HBV infection ^[1].
Complete adverse event profile available in the full prescribing information for bulevirtide (Hepcludex).

What This Means for Clinical Practice

Bulevirtide is indicated for adults with chronic hepatitis delta virus infection, including those without cirrhosis and with compensated cirrhosis. The data supports a 48% combined response rate in the MYR301 trial, providing a new treatment avenue for patients with this challenging condition. What additional long-term safety data will emerge as more patients are treated with bulevirtide?

Study Design

The MYR301 trial was a multi-center, randomized, open-label, parallel-arm phase 3 trial that enrolled 500 adults with chronic HDV infection. Participants were randomly assigned to receive bulevirtide 8.5 mg once daily for 144 weeks or to a delayed treatment group with an observational period of 48 weeks followed by bulevirtide for 96 weeks. Clinicians should consult current prescribing information for full dosing guidance. The primary endpoint was the combined response at week 48, with a follow-up duration of 144 weeks. Key limitations of the trial include the need for further data on long-term efficacy and safety outcomes. Pending data will help clarify the long-term implications of bulevirtide therapy in this population.

FAQ

What is bulevirtide (Hepcludex) approved for?

Bulevirtide is approved for the treatment of chronic hepatitis delta virus (HDV) infection in adults without cirrhosis or with compensated cirrhosis, as of May 22, 2026, based on the MYR301 trial showing a 48% combined response rate versus delayed treatment.

How does bulevirtide work?

Bulevirtide is a virion entry inhibitor that prevents the entry of hepatitis delta virus (HDV) into hepatocytes, thereby reducing viral replication and associated liver damage.

What is the recommended dose of bulevirtide?

Bulevirtide is administered at a dose of 8.5 mg subcutaneously once daily. Clinicians should consult current prescribing information for full dosing guidance. Full dosing guidance is available in the prescribing information for bulevirtide (Hepcludex).

What are the most common side effects of bulevirtide?

Common side effects of bulevirtide include hypersensitivity reactions, injection site reactions, headache, abdominal pain, fatigue, and pruritus. Exact frequencies are not available in public source summaries.

FDA Approves Bulevirtide for HDV: 48% Combined Response in MYR301

FDA Approves Bulevirtide for HDV: 48% Combined Response in MYR301

Clinical Perspective

Clinical Context

Key Findings

Safety & Tolerability

What This Means for Clinical Practice

Study Design

FAQ

References

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