shows an ongoing phase 3 study conducted in the United States and four other countries.
The findings were published in the New England Journal of Medicine.
Led by Heiner Wedemeyer, MD, of Hannover Medical School in Germany, the study included 150 patients with HDV, with and without compensated cirrhosis (mean age, 42 years; 57% male; 83% White). They were randomly assigned to receive 2 mg or 10 mg of bulevirtide subcutaneously daily for 144 weeks or, as a control group, receive no treatment for 48 weeks, followed by 10 mg of bulevirtide daily for 96 weeks. All patients were followed for 96 weeks after treatment ends.
For the primary endpoint, the combined viral and ALT response at week 48 was similar in the 2-mg (45%) and 10-mg (48%) groups, compared with 2% in the control group (one patient). Twelve percent of patients in the 2-mg group and 20% of patients in the 10-mg group had a clinical benefit, compared with none of the patients in the control group.
Among those with a combined response, normalization of the ALT level occurred in most patients by week 24, while the HDV RNA level continued to decline between week 24 and week 48, the authors wrote.
“This surrogate end point is considered to be a reasonably likely predictor of improved clinical outcomes in patients with HDV; however, longer-term data are needed to confirm the clinical benefit of bulevirtide,” the investigators wrote.
The results offer a glimmer of hope, Marc Ghany, MD, MHSc, of the National Institute of Diabetes and Digestive and Kidney Diseases wrote in an accompanying editorial. “The goal of HDV therapy is to improve patient survival by preventing progression to cirrhosis, liver failure, and liver cancer,” he wrote.
In safety results, headache, pruritus, fatigue, and eosinophilia were more common in the bulevirtide groups than in the control group. All adverse events were mild to moderate.
HDV infects about 5% of people with chronic HBV and relies on HBV surface antigen (HBsAg) for transmission and infectivity. Bulevirtide is derived from a region of the large envelope protein of HBsAg and irreversibly binds to the hepatocyte entry receptor for both HDV and HBV.
Bulevirtide has received conditional approval in the European Union. In 2022, the Food and Drug Administration declined to approve bulevirtide over concerns about production and delivery of the drug. There are no approved treatments for HDV in the United States.
The study was supported by Gilead Sciences. Dr. Wedemeyer disclosed research funding, acting as a consultant to, and giving paid lectures on behalf of Gilead Sciences. He and other coauthors disclosed financial relationships with Gilead and other pharmaceutical companies.
