Greenwich LifeSciences, Inc. (Nasdaq: GLSI) provided clinical updates on its Phase III breast cancer immunotherapy trial, FLAMINGO-01, including regulatory-reviewed design changes and preliminary financial figures, according to a press release from the Stafford, Texas-based company.

The trial's Data Safety Monitoring Board met in May 2026 and recommended the study continue without modification. Following review by the U.S. Food and Drug Administration and the European Medicines Agency, the company said several planned protocol modifications have been implemented. These include expanding the maximum enrollment to 2,000 patients, combining all HLA types in the randomized arms, and adjusting the event thresholds for interim analyses to 28 events for the first interim and 56 for the second, with 133 events required to end the study. The trial is designed to detect a hazard ratio of 0.55 in invasive breast cancer-free survival.

The inclusion of non-HLA-A*02 patients, who represent approximately 55% of the eligible population, is expected to increase the enrollment rate by 122%, or 2.22 times the prior rate. The company said more than 1,500 patients have been screened across approximately 170 to 180 sites in 11 countries. The 250-patient non-HLA-A*02 open-label arm is fully enrolled.

Preliminary data from the non-HLA-A*02 open-label arm shows an approximately 70% to 80% reduction in recurrence rate after completion of the primary immunization series, though the company noted this data is early and subject to change.

On the financial side, the company reported an estimated cash balance of approximately $8.9 million as of June 30, 2026, with a second-quarter 2026 burn rate of approximately $2 million, down from $4.7 million in the first quarter. The company said its annual burn rate was approximately $7 million in 2023 and 2024, rising to $10 million in 2025. These preliminary figures are unaudited and subject to change.

The trial is led by Baylor College of Medicine and also subject to review by regulatory authorities in the UK and Canada.