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 underscores the safety profile of the investigational treatment and allows the trial to proceed as planned.
The company also revealed 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 decision to expand the trial reflects a strategic effort to gather more robust data and potentially accelerate the path to regulatory approval.
Greenwich LifeSciences reported 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 broad geographic reach enhances the diversity of the patient population and could support global regulatory submissions.
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, the company emphasized that these findings remain preliminary and are not predictive of the final Phase 3 results. The data suggest potential efficacy, but caution is warranted until final analyses are completed.
The FLAMINGO-01 trial is evaluating GLSI-100, which comprises GP2, a 9 amino acid transmembrane peptide of the HER2 protein. HER2 is a cell surface receptor protein expressed in a variety of common cancers, including 75% of breast cancers at low, intermediate, and high levels. By targeting HER2-expressing cells, GLSI-100 aims to stimulate the immune system to prevent recurrences in patients who have previously undergone surgery.
This news is important because breast cancer recurrence remains a significant clinical challenge. If successful, GLSI-100 could offer a new treatment option for the large population of breast cancer patients with HER2 expression, potentially reducing the risk of relapse and improving long-term outcomes. The expanded study design and continued DSMB support indicate that the trial is on track, but investors and patients should await final results before drawing conclusions about efficacy.
For more information, the full press release is available at https://ibn.fm/elLnN. Additional details about Greenwich LifeSciences can be found on their website at www.greenwichlifesciences.com.
