Greenwich LifeSciences Announces Expansion of Flamingo-01 Clinical Trial to Belgium

STAFFORD, Texas, Oct. 02, 2025 (GLOBE NEWSWIRE) -- Greenwich LifeSciences, Inc. (Nasdaq: GLSI) (the "Company"), a clinical-stage biopharmaceutical company focused on its Phase III clinical trial, FLAMINGO-01, which is evaluating GLSI-100, an immunotherapy to prevent breast cancer recurrences, today announced the expansion of FLAMINGO-01 clinical trial to Belgium.

The Company's application to European regulators has been formally approved, adding Belgium as an approved country in FLAMINGO-01 in addition to Spain, France, Germany, Italy, Poland, Romania, Ireland, Portugal, and the US.

According to the latest data collected by the European Cancer Information System (click here), a total of 11,366 new cases of breast cancer were diagnosed in Belgium in 2022, which is the most common cancer diagnosed in women, representing approximately 33% of all cancers in women. Breast cancer is the leading cause of death from cancer in women in Belgium with 2,324 deaths in 2022.

The Company is collaborating with Patrick Neven, MD, PhD, at UZ Leuven, who will be serving as the national principal investigator in Belgium for FLAMINGO-01. Dr Neven is Full Professor at the Department of Gynecological Oncology, University Hospitals Leuven, and is a staff member of the Multidisciplinary Breast Centre. His research focuses on breast oncology, particularly endocrine therapy and quality of life. He has served as principal investigator in multiple clinical trials, published over 300 peer-reviewed papers, and lectured widely at international meetings. He is president of the Belgian Society of Senology, active in several scientific societies, and has mentored numerous doctors and PhD students in breast cancer care.

CEO Snehal Patel commented, "We thank our steering committee for introducing us to Dr. Neven and look forward to working with him and his colleagues. We are planning start-up activities in Leuven in the coming month. Leuven is centrally located in Belgium and is an ideal location to cover large parts of the country, including Brussels and Antwerp."

FLAMINGO-01 (NCT05232916) is a Phase III clinical trial designed to evaluate the safety and efficacy of GLSI-100 (GP2 + GM-CSF) in HER2 positive breast cancer patients who had residual disease or high-risk pathologic complete response at surgery and who have completed both neoadjuvant and postoperative adjuvant trastuzumab based treatment. The trial is led by Baylor College of Medicine and currently includes US and European clinical sites from university-based hospitals and academic and cooperative networks with plans to open up to 150 sites globally. In the double-blinded arms of the Phase III trial, approximately 500 HLA-A*02 patients will be randomized to GLSI-100 or placebo, and up to 250 patients of other HLA types will be treated with GLSI-100 in a third arm. The trial has been designed to detect a hazard ratio of 0.3 in invasive breast cancer-free survival, where 28 events will be required. An interim analysis for superiority and futility will be conducted when at least half of those events, 14, have occurred. This sample size provides 80% power if the annual rate of events in placebo-treated subjects is 2.4% or greater.

For more information on FLAMINGO-01, please visit the Company's websitehereand clinicaltrials.govhere. Contact information and an interactive map of the majority of participating clinical sites can be viewed under the "Contacts and Locations" section. Please note that the interactive map is not viewable on mobile screens. Related questions and participation interest can be emailed to:flamingo-01@greenwichlifesciences.com

One in eight U.S. women will develop invasive breast cancer over her lifetime, with approximately 300,000 new breast cancer patients and 4 million breast cancer survivors. HER2 (human epidermal growth factor receptor 2) protein is a cell surface receptor protein that is expressed in a variety of common cancers, including in 75% of breast cancers at low (1+), intermediate (2+), and high (3+ or over-expressor) levels.

Greenwich LifeSciences is a clinical-stage biopharmaceutical company focused on the development of GP2, an immunotherapy to prevent breast cancer recurrences in patients who have previously undergone surgery. GP2 is a 9 amino acid transmembrane peptide of the HER2 protein, a cell surface receptor protein that is expressed in a variety of common cancers, including expression in 75% of breast cancers at low (1+), intermediate (2+), and high (3+ or over-expressor) levels. Greenwich LifeSciences has commenced a Phase III clinical trial, FLAMINGO-01. For more information on Greenwich LifeSciences, please visit the Company's website atwww.greenwichlifesciences.comand follow the Company's Twitter athttps://twitter.com/GreenwichLS.

Statements in this press release contain "forward-looking statements" that are subject to substantial risks and uncertainties. All statements, other than statements of historical fact, contained in this press release are forward-looking statements. Forward-looking statements contained in this press release may be identified by the use of words such as "anticipate," "believe," "contemplate," "could," "estimate," "expect," "intend," "seek," "may," "might," "plan," "potential," "predict," "project," "target," "aim," "should," "will," "would," or the negative of these words or other similar expressions, although not all forward-looking statements contain these words. Forward-looking statements are based on Greenwich LifeSciences Inc.'s current expectations and are subject to inherent uncertainties, risks and assumptions that are difficult to predict, including statements regarding the intended use of net proceeds from the public offering; consequently, actual results may differ materially from those expressed or implied by such forward-looking statements. Further, certain forward-looking statements are based on assumptions as to future events that may not prove to be accurate. These and other risks and uncertainties are described more fully in the section entitled "Risk Factors" in Greenwich LifeSciences' Annual Report on the most recent Form 10-K for the year ended December 31, 2024, and other periodic reports filed with the Securities and Exchange Commission. Forward-looking statements contained in this announcement are made as of this date, and Greenwich LifeSciences, Inc. undertakes no duty to update such information except as required under applicable law.