Greenwich LifeSciences, Inc. (NASDAQ: GLSI) provided an update on its Phase 3 FLAMINGO-01 trial evaluating GLSI-100, an immunotherapy designed to prevent breast cancer recurrence. The company announced that the study’s Data Safety Monitoring Board recommended the trial continue without modification following its May 2026 review. Regulatory authorities in the U.S. and Europe have also supported planned protocol changes that include expanding enrollment to as many as 2,000 patients, increasing enrollment rates by including all HLA types, and maintaining enrollment through interim analyses to strengthen the study design and increase the probability of success.
Greenwich LifeSciences reported that more than 1,500 patients have been screened across approximately 170 to 180 clinical sites in 11 countries, with plans to expand into additional European markets as well as the U.K. and Canada. The company also noted preliminary data from the fully enrolled open-label non-HLA-A*02 arm continues to show a 70% to 80% reduction in breast cancer recurrence following the primary immunization series. However, these findings remain preliminary and are not predictive of the final Phase 3 results.
The FLAMINGO-01 trial is a pivotal study for GLSI-100, which targets the GP2 peptide derived from the HER2 protein. HER2 is expressed in 75% of breast cancers at various levels, making this immunotherapy potentially applicable to a broad patient population. The expanded study design aims to increase the likelihood of demonstrating statistically significant efficacy, which could lead to regulatory approval and provide a new treatment option for breast cancer patients at high risk of recurrence.
For more details, the full press release is available at https://ibn.fm/elLnN. Additional information about Greenwich LifeSciences can be found at www.greenwichlifesciences.com.
