What's Happening?
Mirum Pharmaceuticals, Inc. announced that its investigational drug, brelovitug, met the primary endpoint in the Phase 3 AZURE-4 study for treating chronic hepatitis delta virus (HDV). The study demonstrated that 59% of patients receiving brelovitug 300
mg once weekly achieved a combined virologic response and ALT normalization at Week 24, compared to 0% in the delayed-treatment arm. Brelovitug is a fully human monoclonal antibody targeting the hepatitis B surface antigen (HBsAg) on both HDV and hepatitis B virus (HBV). The AZURE-4 study enrolled 113 treatment-naive patients, with a significant portion (53%) having cirrhosis. The drug was well-tolerated, with flu-like illness being the most common adverse event. This marks the second Phase 3 study where brelovitug has met its primary endpoint, reinforcing its potential as a single-agent treatment for chronic HDV.
Why It's Important?
Chronic HDV is considered the most severe form of viral hepatitis, affecting approximately 230,000 people in the United States and Europe. Over 50% of individuals diagnosed with HDV are estimated to die from liver-related causes within 10 years, and currently, there are no approved treatments in most countries. The successful outcome of the AZURE-4 study, following similar results in the AZURE-1 study, is crucial as it indicates a potential new therapeutic option for a patient population with high unmet medical needs. The observed improvements in viral suppression, ALT normalization, and liver stiffness, even in patients with advanced cirrhosis, suggest that brelovitug could significantly alter the disease progression and improve patient outcomes. This development could lead to a new standard of care for HDV patients, offering hope for those facing severe liver disease.
What's Next?
Mirum Pharmaceuticals plans to submit a Biologics License Application (BLA) to the U.S. Food and Drug Administration (FDA) in the first half of 2027. If approved, a potential U.S. commercial launch for brelovitug is anticipated in the fourth quarter of 2027. Full results from the Phase 3 AZURE-4 study are expected to be presented at an upcoming medical congress. The company will continue to highlight long-term brelovitug data, which has shown deepening viral suppression and increased rates of ALT normalization with extended treatment. The regulatory submission and potential market entry will be closely watched by healthcare providers and patients, as it could introduce the first dedicated treatment for chronic HDV in many regions.
