Greenwich Lifesciences Provides Update On Its Phase III Clinical Trial, Flamingo-01, Which Is Evaluating GLSI-100, An Immunotherapy To Prevent Breast Cancer Recurrences

Flamingo-01 Progress to Date & Future Plans

The Company recently confirmed that the preliminary HLA prevalence, safety, and immune response data in FLAMINGO-01 patients is trending as expected in both HLA-A*02 and non-HLA-A*02 arms. The non-HLA-A*02 arm was expanded to 250 patients in 2024 with approval from both EU and US regulators. With the new preliminary positive immune response data in these patients, further changes are being considered, including the potential to transform the non-HLA-A*02 open label third arm into effectively a second Phase III trial which could lead to multiple pathways for marketing approval of GLSI-100 and a larger market potential.

In Q1 2025, the Company achieved its highest screening rate of over 150 patients per quarter or the equivalent of 600 patients per year in 40 US sites and 77 EU sites for a total of 117 active sites. In addition, 30 sites in the EU are planned to be activated in 2025 with the potential for another 10 sites to be approved and added in additional EU countries, bringing the total potential sites to over 150 sites globally. Once these sites are activated, the Company is considering a strategy to continue enrolling in both of the HLA-A*02 and non-HLA-A*02 arms until an interim analysis is conducted and the appropriate size of each arm can be further assessed.

US Clinical Sites Participating in Flamingo-01

Approximately 40 US clinical sites with 134 locations, including sites in the US Oncology/Sarah Cannon network, are currently recruiting patients and are listed below and at www.clinicaltrials.gov/study/NCT05232916. Many of the sites are prominent teaching hospitals, including Yale, Johns Hopkins, Harvard, Huntsman, Moffitt, Stanford, UCSF, UCLA, UCSD, UT Southwestern, UT San Antonio, Columbia, Northwestern, Washington University, Thomas Jefferson, Stony Brook, and Baylor, which is the lead site.

European Clinical Sites and Networks Participating in Flamingo-01

In early 2024, the expansion of Flamingo-01 into 5 EU countries was approved by European regulators. Since that time, 77 clinical trial sites have been activated, and study recruitment is well underway in Spain (29), France (17), Germany (18), Italy (9), and Poland (4).

European academic networks in each country are participating in Flamingo-01 and are listed below. These networks represent the largest oncology focused hospitals and centers in Europe, where breast cancer leaders work in a collaborative manner to help advance promising therapies. The networks hold annual scientific meetings where Flamingo-01 has been introduced and where the Company has presented in the past.

GEICAM is the leading group in breast cancer research in Spain and currently consists of more than 900 experts, who work in more than 200 centers throughout Spain. Since its establishment in 1995, GEICAM has carried out more than one hundred studies in which more than 66,000 women and men have participated.

UCGB or Unicancer is the federation of French comprehensive cancer centers, a major player in cancer research and a network of 20 private, non-profit healthcare centers specialized in oncology, brought together in a health cooperation group.

GBG Forschungs GmbH is one of the world's leading breast cancer research institutes that works together with the academic study group German Breast Group (GBG). With more than 67,000 study participants and 3,500 new patients per year, GBG is the largest breast cancer study group in Germany, consisting of more than 1,000 doctors in over 800 centers. 

GIM (Gruppo Italiano Mammella) is a cooperative Italian network for breast cancer research and therapy. GIM brings together over 150 participating centers and around 500 investigators.