Hepatitis D Patients Maintain Undetectable Virus Nearly 2 Years After Bulevirtide Therapy

In a late-breaking oral presentation at EASL, 36% (23 out of 64) of adults living with chronic hepatitis delta virus (HDV) who were treated with the first-in-class entry inhibitor bulevirtide, at either a 2 mg or 10 mg dose, maintained virologic suppression for nearly 2 years after treatment, following undetectable HDV RNA when they finished their treatment. These findings were part of Gilead’s phase 3 MYR301 trial.

“The findings from this data set that we're sharing at EASL continues to reinforce the fact that bulevirtide is effective; it's very well tolerated; and also showed the potential of bulevirtide to maintain biologic suppression and normalized markers of liver inflammation, such as alt [alanine aminotransferase],” Anu Osinusi, MD, vice president, Clinical Research for Hepatitis, Respiratory and Emerging Viruses, Gilead, said.

Additionally, sustained post-treatment undetectable HDV RNA was more frequent in participants who had longer durations of on-treatment HDV RNA undetectability at the end of their treatment. In fact, 90% of those who had undetectable HDV RNA for ≥96 weeks at the end of their treatment remained HDV undetectable off-treatment.

Osinusi says this data really shows the potential value of bulevirtide monotherapy for this subset of patients living with chronic HDV.

“The longer you were undetectable on treatment was actually associated with a lower risk of post treatment relapse,” Osinusi said. “And of note, what we did see was that there were no late relapses. There were no relapses between week 48 and week 96 post treatment, which just continues to suggest the durability of the post treatment response in this subset of patients.”

Next Steps for the Therapy

Bulevirtide has been approved in the European Economic Area, the United Kingdom, Switzerland, and Australia for chronic HDV infection in HDV RNA-positive adult patients with compensated liver disease. The therapy remains investigational in the United States.

Regarding the timeline for a regulatory filing with the FDA, Osinusi indicated that a biologics license application (BLA) submission could happen in 2025.

“We are actively engaging with the FDA and other regulatory authorities to bring bulevirtide to patients, particularly in the US, given its breakthrough designation and the continued significant unmet medical need,” Osinusi said. “We did receive preliminary agency support to move ahead with a new BLA application later this year.”

This is the second segment of a 2-part interview with Osinusi. To view the first segment, interested parties can go here.

Reference
1. Final Data From the Phase 3 MYR301 Study Demonstrated Longer Treatment With Bulevirtide Was Associated With Sustaining Undetectability After Stopping Treatment. Gilead press release. May 7, 2025. Accessed May 10, 2025.
https://www.gilead.com/news/news-details/2025/final-data-from-the-phase-3-myr301-study-demonstrated-longer-treatment-with-bulevirtide-was-associated-with-sustaining-undetectability-after-stopping-treatment