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 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 disclosed preliminary data from the fully enrolled open-label non-HLA-A*02 arm, which continues to show a 70% to 80% reduction in breast cancer recurrence following the primary immunization series. However, the company emphasized that these findings remain preliminary and are not predictive of the final Phase 3 results.
The FLAMINGO-01 trial is evaluating GLSI-100, which targets the GP2 peptide derived from the HER2 protein. HER2 is expressed in 75% of breast cancers at varying levels. The expanded study design aims to include all HLA types, which could broaden the potential patient population and improve the statistical power of the trial. The DSMB’s recommendation and regulatory support for protocol changes underscore the perceived safety and potential efficacy of the immunotherapy.
For more information, visit the company’s website at www.greenwichlifesciences.com. The full press release is available at https://ibn.fm/elLnN.
Greenwich LifeSciences is a clinical-stage biopharmaceutical company focused on the development of GP2, an immunotherapy to prevent breast cancer recurrences in patients who have previously undergone surgery. The company’s Phase III clinical trial, FLAMINGO-01, represents a significant step toward addressing the high recurrence rates in HER2-expressing breast cancers.
