, based on real-world experience.
These findings suggest that longer follow-up is needed to determine the optimal treatment duration for bulevirtide monotherapy, reported lead author Alexander Killer, MD, of Heinrich Heine University Düsseldorf, Germany, and colleagues.
Heinrich Heine University
Dr. Alexander Killer
Bulevirtide was conditionally approved by the European Medicines Agency in 2020 and is on track for full marketing approval in Europe, but it remains unavailable in the United States, where Gilead, the manufacturer, has faced regulatory hurdles.
In the MYR202 and 301 clinical trials, bulevirtide significantly reduced HDV-RNA levels in 54% of patients after 24 weeks, and reduced viremia while normalizing ALT in 48% of patients after 48 weeks.
“Given its standalone status and good treatment tolerance even in patients with compensated cirrhosis, this represents a step change in the treatment of HDV-coinfected individuals,” Dr. Killer and colleagues wrote in Gastro Hep Advances.
Yet dynamics of response and clinical predictors of treatment outcome remain unclear, prompting Dr. Killer and colleagues to conduct the present retrospective study. The dataset included 15 patients who received bulevirtide for at least 1 year at a single center in Germany.
The analysis focused on monthly changes in biochemical and virologic parameters. The investigators also screened for clinical factors that might predict responses to therapy.
Treatment response rate and safety profile aligned with data from clinical trials, suggesting that bulevirtide is safe and effective in a real-world setting.
Patients typically achieved ALT normalization 2-6 months into therapy, followed by virologic response at least 6 months after starting treatment, with one-third of patients requiring at least 1 year to achieve HDV-RNA negativity.
“Of note, normalization of ALT under bulevirtide treatment occurs earlier than the decline of HDV-RNA levels, which contrasts with the response seen to nucleos(t)ide analog treatment in hepatitis B,” the investigators wrote. They suggested that this may be due to bulevirtide’s distinct mechanism of action.
Severe hepatitis was associated with lower response rates in the first year. Possible predictors of delayed response included low body mass index and high alpha-fetoprotein.
Of note, two patients had ALT normalization without virologic response.
“It is unclear whether these patients actually have worse outcomes in terms of overall success than patients with a combined response, especially since these patients experienced a decline of more than 1 log,” Dr. Killer and colleagues wrote, noting that a 1 log reduction is considered an intermediate virologic response, and hepatitis B virus (HBV) studies have shown that severe liver events are prevented by early ALT normalization. “Therefore, it does not seem appropriate to categorize patients with biochemical responses as ‘treatment nonresponders’ [according to FDA criteria].”
The investigators called for longer observational studies to determine the optimal duration of bulevirtide monotherapy.
This study was funded by the Ministry of Culture and Science of the State of North Rhine-Westphalia and the German Research Foundation. The investigators disclosed relationships with Novartis, GSK, AbbVie, and others.
