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. This recommendation supports the ongoing evaluation of GLSI-100 in patients with HER2-positive breast cancer who have previously undergone surgery.
The company also reported that regulatory authorities in the United States and Europe have supported planned protocol changes. These changes include expanding enrollment to as many as 2,000 patients, increasing enrollment rates by including all HLA types, and maintaining enrollment through interim analyses. These modifications are intended to strengthen the study design and increase the probability of success. The expanded enrollment criteria may accelerate patient recruitment and enhance the generalizability of the trial results.
Greenwich LifeSciences stated that more than 1,500 patients have been screened across approximately 170 to 180 clinical sites in 11 countries. The company plans to expand into additional European markets as well as the United Kingdom and Canada. This geographic expansion could broaden the patient population and support eventual regulatory submissions in these regions.
Additionally, the company reported preliminary data from the fully enrolled open-label non-HLA-A*02 arm. These data continue 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. Investors should interpret these early data with caution.
GLSI-100 is a peptide-based immunotherapy targeting GP2, a transmembrane peptide of the HER2 protein. HER2 is expressed in 75% of breast cancers at low, intermediate, and high levels. The therapy is designed to stimulate the immune system to target residual cancer cells after surgery, potentially reducing the risk of recurrence.
The FLAMINGO-01 trial is a pivotal study that could support regulatory approval of GLSI-100 if positive results are achieved. The DSMB's recommendation to continue without modification provides confidence in the trial's safety profile. The expanded study design, including enrollment of all HLA types, may improve the likelihood of demonstrating efficacy across a broader patient population.
For more information, visit the company's website at www.greenwichlifesciences.com. The full press release is available at https://ibn.fm/elLnN.
