Mirum Pharmaceuticals Hits Key Milestones in Hepatitis Delta Virus Trial

Event summary

  • Mirum Pharmaceuticals completed enrollment in Phase 3 AZURE-1 study and screening in Phase 3 AZURE-4 study for brelovitug in chronic hepatitis delta virus (HDV).
  • Topline 24-week data from both studies expected in the second half of 2026.
  • Brelovitug has received Breakthrough Therapy designation from the FDA for chronic HDV treatment.
  • AZURE-1 and AZURE-4 studies will form the basis of Mirum’s U.S. Biologics License Application (BLA) submission.
  • Brelovitug demonstrated strong antiviral activity in Phase 2 study, achieving 100% HDV RNA response.

The big picture

Mirum Pharmaceuticals is advancing brelovitug, a potential first-in-class treatment for chronic hepatitis delta virus, a severe form of viral hepatitis with no approved therapies in the U.S. The completion of key Phase 3 trial milestones positions Mirum for a potential BLA submission and launch in 2027, addressing a critical unmet need in the rare disease space. The strategic significance lies in Mirum’s ability to leverage its rare disease expertise and strong connections to patient communities to bring forward breakthrough medicines.

What we're watching

Regulatory Pathway
Whether the FDA’s Breakthrough Therapy designation will expedite brelovitug’s approval process and potential launch in 2027.
Clinical Efficacy
How the topline data from AZURE-1 and AZURE-4 will compare to the strong antiviral activity observed in the Phase 2 study.
Market Opportunity
The pace at which Mirum can capture market share in the HDV treatment space, given the lack of approved therapies in the U.S.