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 (DSMB) recommended the trial continue without modification following its May 2026 review. Regulatory authorities in the U.S. and Europe have 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 said 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 reported 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, while maintaining that these findings remain preliminary and are not predictive of the final Phase 3 results.
The FLAMINGO-01 trial is evaluating GP2, a 9 amino acid transmembrane peptide of the HER2 protein, which is expressed in 75% of breast cancers at low, intermediate, and high levels. Greenwich LifeSciences is a clinical-stage biopharmaceutical company focused on developing GP2 to prevent breast cancer recurrences in patients who have previously undergone surgery. For more information, visit the company's website at www.greenwichlifesciences.com.
This announcement highlights the progress of a potentially important immunotherapy for breast cancer patients. The expanded study design and continued DSMB support suggest confidence in the trial's direction, though final results are pending. The preliminary data showing a significant reduction in recurrence in the non-HLA-A*02 arm is encouraging but must be interpreted with caution.
Investors and patients will be watching for further updates as enrollment expands and interim analyses are conducted. The company's ability to enroll across multiple countries and HLA types may enhance the generalizability of the findings. The full press release is available at https://ibn.fm/elLnN.
