Vir says hepatitis D drug combination succeeds in first pivotal study

Vir Biotechnology reported Sunday afternoon that its chronic hepatitis D treatment succeeded in the first of three planned late-stage studies, according to Endpoints News. The company said 44% of patients who received once-monthly doses of tobevibart and a companion agent met the study’s response criteria, a result Vir is positioning as evidence of the regimen’s efficacy against the rare liver disease.

The announcement intensifies competition in a hepatitis D treatment landscape that includes Gilead Sciences and Mirum Pharmaceuticals, both of which have programs targeting the same condition. Endpoints News frames the result as a pivotal milestone for Vir, marking the first of three studies required to support the drug’s case for approval.

Hepatitis D, caused by a defective virus that can only infect people already carrying hepatitis B, is considered one of the most severe forms of viral hepatitis and carries an elevated risk of liver failure and cirrhosis. Treatment options have historically been limited, leaving patients and physicians with few tools beyond management of symptoms and, in some cases, liver transplantation.

Further detail on trial design, patient population size, and secondary endpoints was not included in the available reporting. The outcome of the two remaining late-stage studies will determine whether Vir’s regimen advances toward regulatory filing, a process that typically follows the completion of all pivotal trials in a given program.