Greenwich Lifesciences Inc Stock Price, News & Analysis

Greenwich LifeSciences (Nasdaq: GLSI) provided updates on its Phase III trial FLAMINGO-01 evaluating Fast Track designated GLSI-100 to prevent breast cancer recurrence and on corporate strategy on Dec 22, 2025.

Key points: the FLAMINGO-01 DSMB met twice in 2025 and recommended continuing the study without modification; ~140 sites are actively enrolling with plans to activate ~10 additional approved sites in 2026 and to pursue sites in the UK and Canada; planned protocol modifications (subject to regulatory approval) include resizing the study and increasing enrollment rate; the company reports an annual cash burn of approximately $7 million (2023–2025) and is using an ATM financing strategy to support operations while pursuing partnerships.

Greenwich LifeSciences (Nasdaq: GLSI) reported a preliminary analysis from the open-label non-HLA-A*02 arm of FLAMINGO-01 showing an approximately 80% reduction in recurrence rate in the fully enrolled 250-patient arm by two analytic methods. Method 1 compared treated patients after the Primary Immunization Series to historical T-DM1 (KATHERINE) recurrence rates; Method 2 compared recurrence during the 6-month PIS (100 patient-years) to post-PIS follow-up (132 patient-years). The first patient completed all primary and booster vaccinations. Results are preliminary, the arm has no direct placebo comparator, and data are not completed or fully reviewed.

Greenwich LifeSciences (Nasdaq: GLSI) announced completion of enrollment in the 250-patient open-label non-HLA-A*02 arm of its Phase III FLAMINGO-01 trial of GLSI-100 to prevent breast cancer recurrence on Dec 8, 2025. The company said non-HLA-A*02 patients represent about 55% of the trial population and about 250 non-HLA-A*02 patients have now been treated. Approximately 500 HLA-A*02 patients remain planned for randomization to GLSI-100 or placebo. Greenwich is reviewing immune response, safety, and recurrence-rate data from the 250-patient cohort and may seek regulatory approval to resume randomized enrollment of non-HLA-A*02 patients. The company reiterated prior Phase IIb comparisons and cited patent and market-potential estimates.

Greenwich LifeSciences (Nasdaq: GLSI) provided a global update on its Phase III trial FLAMINGO-01 evaluating GLSI-100 to prevent breast cancer recurrence. The company has screened over 1,000 patients to date across 140 active sites (about 40 US sites and 100 EU sites).

Screening is progressing at ~150 patients per quarter (~600 per year). Management is considering continuing enrollment in both the HLA-A*02 and non-HLA-A*02 arms until interim analyses define appropriate arm sizes, and reports interest from additional countries to join the study.

Greenwich LifeSciences (Nasdaq: GLSI) announced expansion of its Phase III trial FLAMINGO-01 of GLSI-100 to Austria after formal European regulator approval on Oct 9, 2025. Austria is added to existing approved countries including Spain, France, Germany, Italy, Poland, Romania, Ireland, Portugal, Belgium, and the US.

The company cited Austrian cancer data showing 6,070 new breast cancer cases in 2022 and 1,789 breast cancer deaths in 2022. Greenwich is collaborating with principal investigators at Ordensklinikum Linz, has begun site training, and said it hopes to activate the Linz site in 2025 while considering additional sites in Vienna and Salzburg.

Greenwich LifeSciences (NASDAQ:GLSI) has announced the expansion of its Phase III FLAMINGO-01 clinical trial to Belgium, marking the tenth country approval for the study. The trial evaluates GLSI-100, an immunotherapy designed to prevent breast cancer recurrences.

The company will collaborate with Dr. Patrick Neven at UZ Leuven as the national principal investigator. Belgium reported 11,366 new breast cancer cases in 2022, representing 33% of all female cancers, with 2,324 deaths recorded. The strategic location of Leuven will facilitate coverage of major Belgian regions, including Brussels and Antwerp.

Greenwich LifeSciences (NASDAQ:GLSI) has received regulatory approval to expand its FLAMINGO-01 Phase III clinical trial to Portugal, joining existing trial locations in Spain, France, Germany, Italy, Poland, Romania, Ireland, and the US. The trial evaluates GLSI-100, an immunotherapy designed to prevent breast cancer recurrences.

Dr. Luís António Marques da Costa, Associate Professor of Medicine and Head of Clinical Translational Oncology Research Unit at the Institute of Molecular Medicine, will serve as Portugal's national principal investigator. According to recent data, Portugal reported 9,065 new breast cancer cases in 2022, accounting for 30% of all female cancers, with 2,211 deaths recorded.

The company is currently activating trial sites in Lisbon and evaluating additional locations in central and northern Portugal.

Greenwich LifeSciences (Nasdaq: GLSI) has announced the expansion of its Phase III FLAMINGO-01 clinical trial to Ireland, following regulatory approval. The trial evaluates GLSI-100, an immunotherapy designed to prevent breast cancer recurrences.

The expansion adds Ireland to the existing trial locations in Spain, France, Germany, Italy, Poland, Romania, and the US. According to European Cancer Information System data, Ireland reported 3,723 new breast cancer cases in 2022, representing 30% of all women's cancers, with 883 deaths.

Dr. Janice Walshe, a prominent member of Cancer Trials Ireland, will serve as the national principal investigator at St Vincent's University Hospital in Dublin.

Greenwich LifeSciences (NASDAQ:GLSI) announced that the FDA has granted Fast Track designation for GLSI-100, its immunotherapy treatment for HLA-A*02 breast cancer patients. This designation may accelerate drug approval through enhanced FDA communication and rolling review process.

The company's Phase IIb clinical trial demonstrated impressive results with an 80% or greater reduction in cancer recurrences over 5 years in HER2/neu 3+ patients. The treatment showed no serious adverse events and was well-tolerated across 146 treated patients. GLSI-100 achieved peak immunity at 6 months, with booster injections providing extended protection.