Mirum Pharmaceuticals, Inc. filed a Form 8-K on November 10, 2026, announcing that brelovitug met the primary endpoint in the Phase 3 AZURE-4 study evaluating the drug for the treatment of chronic hepatitis delta virus, and highlighting long-term brelovitug data presented at the American Association for the Study of Liver Diseases.

Key Highlights

  • Primary endpoint met: At Week 24, 59% of patients receiving brelovitug 300 mg QW and 44% receiving 900 mg Q4W achieved the combined endpoint of virologic response and ALT normalization, versus 0% in the delayed-treatment arm (p≤0.0001 for both comparisons).
  • Study population: AZURE-4 enrolled 113 treatment-naïve patients randomized 2:1:1 across the two brelovitug dose groups and a delayed-treatment arm, with 53% of participants having cirrhosis.
  • Virologic response rates at Week 24: 95% of patients in the 300 mg QW arm and 96% in the 900 mg Q4W arm achieved virologic response, defined as at least a 2 log10 reduction in HDV RNA from baseline, HDV RNA below the lower limit of quantification, or undetectable HDV RNA.
  • Safety profile: The most common adverse event was flu-like illness, reported in 17.2% and 18.5% of participants in the 300 mg QW and 900 mg Q4W groups, respectively; injection site reactions were reported in 1.7% and 7.4%, respectively.
  • Regulatory plan: The company disclosed plans to submit a Biologics License Application to the FDA in the first half of 2027, with a potential U.S. commercial launch in the fourth quarter of 2027, if approved.
  • AASLD presentations: Data across three presentations at The Liver Meeting 2026 showed deepening viral suppression, increased ALT normalization rates, and improvements in liver stiffness with longer brelovitug treatment, including in patients with advanced cirrhosis.

AZURE-4 Results and Long-Term Brelovitug Data for Chronic HDV Treatment

According to the filing, Mirum Pharmaceuticals is developing brelovitug, described as "an investigational fully human monoclonal antibody that binds to hepatitis B surface antigen," for the treatment of chronic hepatitis delta virus. The AZURE-4 study is the second of two Phase 3 studies intended to form the basis of the company's U.S. registration package for brelovitug. The study enrolled patients with substantial disease burden, with a mean baseline alanine aminotransferase of 122 U/L and approximately half of participants having baseline HDV RNA levels greater than 6 log10 IU/mL.

The filing reports that the combined primary endpoint, requiring both virologic response and ALT normalization at Week 24, was achieved by 59% of the 300 mg QW group (n=58) and 44% of the 900 mg Q4W group (n=27), compared with 0% in the delayed-treatment arm. Virologic response was defined in the filing as "at least a 2 log10 reduction in HDV RNA from baseline, HDV RNA below the lower limit of quantification (LLOQ, <10 IU/mL), or undetectable HDV RNA (TND)." The table presented in the filing also shows data from the Phase 3 AZURE-1 study at 24 and 48 weeks, as well as Phase 2 data at 108 weeks, with the 108-week Phase 2a cohort of 900 mg patients (n=15) achieving a 100% combined endpoint rate.

The filing states that brelovitug "was well tolerated across dose groups, with no new safety signals observed" in AZURE-4. Statements regarding the anticipated BLA submission and potential commercial launch are described by the filing as forward-looking statements subject to risks and uncertainties, and the company cautions that "actual results may differ from those set forth in this report." The filing was signed by Christopher Peetz, Chief Executive Officer, on November 10, 2026, on behalf of Mirum Pharmaceuticals (NASDAQ:MIRM).

What Was Disclosed

Mirum Pharmaceuticals disclosed Phase 3 AZURE-4 top-line results showing brelovitug met its primary combined endpoint at Week 24, presented long-term Phase 2 and Phase 3 AZURE-1 data at AASLD 2026, and outlined a regulatory timeline targeting a BLA submission in the first half of 2027.