Mirum Pharmaceuticals said its experimental drug brelovitug met the primary endpoint in the phase 3 AZURE-1 trial for chronic hepatitis delta virus infection.

At week 24, 56 per cent of patients on the 300 mg weekly dose and 45 per cent on the 900 mg every-four-weeks dose met the combined endpoint of virus reduction and liver inflammation normalisation. None of the delayed-treatment group responded.

About 85 per cent of treated patients achieved a virus response. The drug was well tolerated across dose groups, the company said.

Hepatitis delta is the most aggressive form of viral hepatitis. It occurs only in people already infected with hepatitis B and can lead to cirrhosis and liver failure.

Mirum plans to file for US approval in the first half of 2027, with a possible launch in late 2027. Full phase 3 results will be presented at an upcoming medical congress.

A second pivotal study, AZURE-4, is expected to report topline results in the fourth quarter of 2026.