Greenwich LifeSciences Reports 46% HLA-A*02 Prevalence in FLAMINGO-01 Trial for Breast Cancer Vaccine

Key Insights

• Initial analysis of FLAMINGO-01 trial reveals 46% of screened patients carry at least one HLA-A*02 allele, a crucial factor for GLSI-100 breast cancer vaccine treatment.
• The trial's open-label arm studying non-HLA-A*02 patients has been expanded from 100 to 250 participants following FDA and EMA approval.
• The Phase III trial design includes approximately 500 HLA-A*02 positive patients in randomized arms, with an additional open-label arm to investigate vaccine efficacy in other HLA types.

Greenwich LifeSciences has revealed key preliminary data from its FLAMINGO-01 trial, reporting that approximately 46% of screened patients possess at least one HLA-A*02 allele, a critical genetic marker for their investigational breast cancer vaccine GLSI-100.

The ongoing Phase III trial maintains its double-blind status while providing valuable insights through analysis of HLA data across both the randomized arms and the open-label cohort. This analysis encompasses patients in the HLA-A*02 treated and placebo arms, as well as a third open-label arm investigating other HLA types.

Trial Design and Patient Stratification

The Phase III FLAMINGO-01 study employs a prospective, randomized, double-blinded, multi-center design. The trial's structure includes careful patient stratification to ensure balanced populations between treatment and placebo arms. Approximately 500 patients positive for the HLA-A*02 allele will be randomized between GLSI-100 treatment and placebo control, with a planned interim analysis to assess progress.

Expanded Open-Label Component

In a significant development, the open-label arm of the trial, which focuses on patients without the HLA-A*02 allele, has been expanded from its initial target of 100 patients to 250 participants. This expansion follows recommendations from the trial's steering committee and has received approval from both the FDA and EMA. The increased sample size may provide sufficient statistical power to draw meaningful conclusions about immune response and efficacy in this population.

Clinical Implications

The open-label arm serves a crucial role in investigating GLSI-100's safety and efficacy profiles in patients lacking the HLA-A*02 allele. This comprehensive approach allows for broader understanding of the vaccine's potential across different genetic profiles. The trial design enables analysis of HLA type distribution across various racial and ethnic groups, based on patient self-reporting, potentially providing valuable insights into population-specific responses to the treatment.