Mirum's Brelovitug Phase 2b Data Shows Promise in Hepatitis Delta Treatment

Event summary

  • Mirum Pharmaceuticals announced that the Phase 2b portion of the AZURE-1 study for brelovitug met its primary endpoint in chronic Hepatitis Delta Virus (HDV) treatment.
  • Data from 53 patients at Week 24 showed 100% virologic response in the 300 mg once weekly arm and 75% in the 900 mg once every four weeks arm, compared to 0% in the delayed treatment arm.
  • The primary composite endpoint (virologic response + ALT normalization) was achieved in 45% and 35% of patients in the respective arms, versus 0% in the delayed arm.
  • Full results will be presented at the European Association for the Study of the Liver (EASL) Congress in May 2026, with Phase 3 data expected in H2 2026.
  • Mirum anticipates a potential BLA submission and commercial launch in the U.S. in 2027.

The big picture

Chronic Hepatitis Delta Virus (HDV) represents a significant unmet medical need, affecting an estimated 230,000 people in the US and Europe, with a high mortality rate. Mirum's brelovitug offers a potential first-in-class treatment, but the small patient population and lack of existing therapies create both opportunity and risk for commercial success. The Phase 3 data will be critical in determining the drug's path to approval and its potential to disrupt the current standard of care, which is largely supportive.

What we're watching

Regulatory Pathway
The FDA's acceptance of the Breakthrough Therapy Designation will influence the speed and rigor of the upcoming Phase 3 trials and potential BLA review, particularly given the lack of existing HDV treatments.
Phase 3 Execution
The success of the Phase 3 AZURE-1 and AZURE-4 trials will hinge on patient recruitment and retention, given the relatively small patient population affected by HDV.
Commercial Adoption
The ultimate commercial viability of brelovitug will depend on pricing and reimbursement strategies, as well as physician and patient acceptance of a novel monoclonal antibody for a rare disease.

Related topics

Pharmaceuticals Drug Development Biotechnology Clinical Trial