Briacell presents phase 3 biomarker data at ESMO 2025

Executive Summary

• Briacell Therapeutics presented encouraging clinical biomarker data from its pivotal Phase 3 study of Bria-IMT plus an immune checkpoint inhibitor (CPI) for metastatic breast cancer (MBC) at the ESMO 2025 Congress.
• The data, derived from a pooled analysis of 113 patients, validated the neutrophil to lymphocyte ratio (NLR) as a potential biomarker for clinical benefit, showing significantly higher progression-free survival (PFS) in patients with an NLR between 0.7 and 2.3.
• The treatment regimen was well-tolerated with no treatment-related discontinuations due to adverse events, and the company continues to await interim data analysis upon the occurrence of 144 patient events (deaths) to assess overall survival.

Key Details

• Study Design: Pivotal Phase 3 randomized trial (BRIA-ABC) comparing Bria-IMT + CPI, Treatment of Physician's Choice, and Bria-IMT monotherapy in late-stage MBC.
• Patient Cohort: Pooled data available for 113 patients as of poster submission; median of six prior lines of treatment (range: 2 to 13).
• Biomarker Findings (NLR):
  • Patients with NLR between 0.7 and 2.3 showed a median PFS of 4.5 months.
  • Patients with NLR < 0.7 or > 2.3 showed a median PFS of 2.5 months.
  • Hazard Ratio (HR): 0.5 (95% CI 0.3 to 0.8, p = 0.005).
• Safety Profile: No new safety or tolerability issues identified in the pooled analysis. No treatment-related discontinuations due to adverse events (AEs). Most common AEs were minor, including fatigue, anemia, and nausea.
• Blinded Data: PFS data comparing Bria-IMT combination regimen versus physician's choice remains blinded.
• Future Milestones: Interim data analysis is scheduled to occur once 144 patient events (deaths) are observed, with overall survival (OS) as the primary endpoint.
• Regulatory Status: Bria-IMT combination regimen has received FDA Fast-Track designation. Positive Phase 3 results could lead to full approval and marketing authorization.

Notable Quotes

• "We are encouraged by the early constructive clinical biomarker data which could allow us to predict clinical and survival outcomes in our patients and would help guide treatment decisions for metastatic breast cancer patients with limited options," stated Dr. William V. Williams, Briacell's president and chief executive officer.