GP2

STAFFORD, Texas, April 03, 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 provided the following global update on FLAMINGO-01. 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. Flamingo-01 Steering Committee The Steering Committee is now comprised of the following experts in the field of breast cancer oncology representing prominent teaching hospitals in the US and 4 of the largest breast oncology networks in the US, Germany, France, and Spain: Dr. Mothaffar F. Rimawi – Professor of Medicine at the Baylor College of Medicine and Executive Medical Director and Co-Leader, Breast Cancer Program of the Dan L Duncan Comprehensive Cancer CenterDr. Francois-Clement Bidard – Professor of Medical Oncology, UVSQ/Paris Saclay University, Head of Breast Cancer Group, Institut Curie, Vice-Chair of the French Breast Cancer research group UCBG (Unicancer)Dr. William J. Gradishar – Professor of Medicine at the Feinberg School of Medicine at Northwestern University, Chief of Hematology and Oncology in the Department of Medicine, and Betsy Bramsen Professor of Breast OncologyDr. Sibylle Loibl – Professor (apl) Goethe University Frankfurt/M, Clinical Consultant Centre for Haematology and Oncology/Bethanien Frankfurt/M, CEO of GBG Forschungs GmbH & Chair of the German Breast Group (GBG)Dr. Miguel Martin – Professor of Medicine, Head, Medical Oncology Service, Gregorio Marañón General University Hospital, Complutense University, Madrid, CEO of GEICAMDr. Joyce A. O’Shaughnessy – Celebrating Women Chair in Breast Cancer, Baylor University Medical Center and Chair, Breast Cancer Program, Texas Oncology, US Oncology, Dallas, TexasDr. Hope S. Rugo – Professor of Medicine and Winterhof Family Professor of Breast Oncology and Director, Breast Oncology and Clinical Trials Education, University of California, San Francisco, Helen Diller Family Comprehensive Cancer CenterDr. Cesar A. Santa-Maria – Associate Professor of Oncology, Breast and Gynecological Malignancies Group, Director of Breast Cancer Trials, Johns Hopkins Sidney Kimmel Comprehensive Cancer CenterDr. Laura M. Spring – Assistant Professor, Medicine, Harvard Medical School, Attending Physician, Medical Oncology, Massachusetts General Hospital CEO Snehal Patel commented, "Based on the high quarterly screening rate, the current level of interest in the FLAMINGO-01 trial is very high. The Company spent considerable time in Europe this past year training and activating all 77 sites. As these are the largest countries in Europe and the sites are distributed near large population centers, we hope to give as many patients as possible an opportunity to participate in the study. The prestigious sites participating in the study and the prominent KOLs at these sites and on our steering committee have helped to further validate the promise of GLSI-100 and have created momentum that is increasing patient awareness of the Phase IIb results and interest in participating in FLAMINGO-01." Mr. Patel further added, "With the preliminary analysis of open label data of the Phase III trial complete, we will continue to analyze the open label data, potentially leading to future publications. We will also try to improve the conduct and design of the study with the ultimate goal to reproduce the Phase IIb results, if possible, and to prepare a treatment process that can be easily commercialized. To that end, we are also giving much consideration to the commercial manufacturing, packaging, and distribution of GLSI-100 and have been developing our manufacturing and regulatory strategy for both the US and Europe in parallel to conducting the clinical trial. Our patent strategy includes filing our own patent claims to potentially further extend the patent life of GLSI-100 in addition to the current 12 years of biological exclusivity that GLSI-100 will be eligible for in the US." List of US Clinical Sites Participating in Flamingo-01 Phase III Clinical Trial Patients who are interested in participating in the Flamingo-01 Phase III clinical trial can learn more about the study at www.clinicaltrials.gov/study/NCT05232916. Each clinical trial site location is listed on the website under "Contacts and Locations" with a new feature showing each site on a map. Patients should contact a participating clinical trial site near them or Flamingo-01@GreenwichLifeSciences.com for screening. The current listing of US sites from the clinicaltrials.gov website with email contact information for some sites is shown below and will be continually updated during the trial. ArizonaArizona Oncology Associates, PC - HOPETucson, Arizona, United States, 85745Contact: Stacey Kimbell, R.N. Stacey.Kimbell@usoncology.comPrincipal Investigator: Aisha Ahmed, MD CaliforniaProvidence Medical FoundationFullerton, California, United States, 92835Contact: Rebeca Sanchez 714-446-5177 rebeca.sanchez2@providence.orgContact: Linda Gozar linda.gozar@stjoe.orgPrincipal Investigator: Monica Lee, MDUniversity of California San DiegoLa Jolla, California, United States, 92093Contact: Sauntee Braddock 858-534-8248 sbraddock@health.ucsd.eduPrincipal Investigator: Rebecca Shatsky, MDUniversity of Southern CaliforniaLos Angeles, California, United States, 90033University of California, Los AngelesLos Angeles, California, United States, 90404Contact: Monica Rocha MPRocha@mednet.UCLA.eduPrincipal Investigator: Aashini Master, DOStanford Women's Cancer CenterPalo Alto, California, United States, 74304Contact: Michelle Le 650-721-4076 michmle@stanford.eduPrincipal Investigator: Fauzia Riaz, MDUniversity of California, San Francisco Helen Diller Family Cancer CenterSan Francisco, California, United States, 94158Contact: Amy Deluca 415-353-7288 amy.deluca@ucsf.eduPrincipal Investigator: Laura Huppert, MDPIH Health Whittier HospitalWhittier, California, United States, 90602Contact: Kristine Bradbury Kristine.Bradbury@pihhealth.orgPrincipal Investigator: Lisa Wang, MD ColoradoRocky Mountain Cancer CentersDenver, Colorado, United States, 80220Contact: Jennifer Hege Jennifer.Hege@USOncology.comPrincipal Investigator: Mabel Mardones, MD ConnecticutYale UniversityNew Haven, Connecticut, United States, 06511Contact: Adam Blanchard adam.blanchard@yale.eduPrincipal Investigator: Michael DiGiovanna, MD District of ColumbiaJohns Hopkins MedicineWashington, District of Columbia, United States, 20016Contact: Hayden Chae, RN 202-364-7620 hchae5@jhmi.eduPrincipal Investigator: Cesar Santa-Maria, MD FloridaUniversity of MiamiCoral Gables, Florida, United States, 33146Contact: Maria Ferrer-Guerra mtf89@med.miami.eduPrincipal Investigator: Elisa Krill-Jackson, MDMoffitt Cancer CenterTampa, Florida, United States, 33612Contact: Julian Guerrero Julian.Guerrero@Moffitt.orgPrincipal Investigator: Aixa Soyano Muller, MD IllinoisNorthwestern UniversityChicago, Illinois, United States, 60611Contact: clinicaltrials@northwestern.eduPrincipal Investigator: William Gradishar, MD MarylandMaryland Oncology HematologyAnnapolis, Maryland, United States, 21401Contact: Gloria Seho-Ahiable Gloria.Seho-Ahiable@USOncology.comPrincipal Investigator: Jeanine Werner, MD MassachusettsMassachusetts General HospitalBoston, Massachusetts, United States, 02114Contact: MGH Cancer Center New Patient Access Team 877-394-5128Principal Investigator: Laura Spring, MD MinnesotaMinnesota OncologyMaple Grove, Minnesota, United States, 55369Contact: Kayla McDonald kayla.mcdonald1@usoncology.comPrincipal Investigator: Eric Lander, MD MissouriWashington University Siteman Cancer CenterSaint Louis, Missouri, United States, 63110Contact: Tracy Summa 314-362-0263 tracy.summa@wustl.eduPrincipal Investigator: Faisal Fa'ak, MD NebraskaNebraska Cancer SpecialistsOmaha, Nebraska, United States, 68114Contact: Heather Cordes hcordes@nebraskacancer.comPrincipal Investigator: Mary Heurter Wells, MDUniversity of Nebraska Medical CenterOmaha, Nebraska, United States, 68198Contact: jairam.krishnamurthy@unmc.eduPrincipal Investigator: Jairam Krishnamurthy, MD NevadaComprehensive Cancer Centers of NevadaHenderson, Nevada, United States, 89052Contact: Lindsay Kondo lindsay.kondo@usoncology.comPrincipal Investigator: Stephani Christensen, MD New JerseyCooper UniversityCamden, New Jersey, United States, 08103Contact: 855-632-2667 Researchcancer@cooperhealth.eduPrincipal Investigator: Ahmed K Abou-Hussein, MD New YorkNew York Oncology HematologyClifton Park, New York, United States, 12065Contact: Josephine Faruol josephine.faruol@usoncology.comPrincipal Investigator: Karen Tedesco, MDColumbia UniversityNew York, New York, United States, 10032Contact: cancerclinicaltrials@CUMC.Columbia.eduPrincipal Investigator: Julia McGuinness, MDStony Brook UniversityStony Brook, New York, United States, 11794Contact: Pushpa Talanki Pushpa.talanki@stonybrookmedicine.eduContact: Jules Cohen jules.cohen@stonybrookmedicine.eduPrincipal Investigator: Jules Cohen, MD OhioOncology Hematology CareCincinnati, Ohio, United States, 45211Contact: Douglas Hart Douglas.Hart@usoncology.comPrincipal Investigator: Patrick Ward, MD OregonCompass OncologyTigard, Oregon, United States, 97223Contact: Jennifer Thompson Jennifer.Thompson@usoncology.comPrincipal Investigator: Jay Andersen, MD PennsylvaniaRedeemer HealthMeadowbrook, Pennsylvania, United States, 19046Contact: Nadine Varney 215-544-5832 nvarney@holyredeemer.comPrincipal Investigator: Danny Markabawi, MDThomas Jefferson UniversityPhiladelphia, Pennsylvania, United States, 19107Contact: 215-600-9151 onctrialnow@jefferson.eduPrincipal Investigator: Maysa Abu-Khalaf, MD TexasTexas Oncology - AustinAustin, Texas, United States, 78745Contact: Sara Manning Sara.Manning@usoncology.comPrincipal Investigator: Kathryn Hudson, MDTexas Oncology - DallasDallas, Texas, United States, 75246Contact: Christine Terraciano Christine.Terraciano@usoncology.comPrincipal Investigator: Cynthia Osborne, MDTexas Oncology - Dallas Presbyterian HospitalDallas, Texas, United States, 75231Contact: Nancy Jones nancy.jones@usoncology.comPrincipal Investigator: Kristi McIntyre, MDThe University of Texas Southwestern Medical CenterDallas, Texas, United States, 75390Contact: Meredith Carter meredith.carter@utsouthwestern.eduPrincipal Investigator: Nisha Unni, MDBaylor College of MedicineHouston, Texas, United States, 77057Contact: Maria Rodriguez maria.rodriguez3@bcm.eduPrincipal Investigator: Mothaffar Rimawi, MDThe University of Texas Health Sciences Center at San AntonioSan Antonio, Texas, United States, 78229Contact: Epp Goodwin 210-450-5798 goodwine@uthscsa.eduPrincipal Investigator: Virginia Kaklamani, MDTexas Oncology - San AntonioSan Antonio, Texas, United States, 78240Contact: Shannon Syring Shannon.Syring@usoncology.comPrincipal Investigator: Emmalind Aponte, MDTexas Oncology - Gulf CoastSugar Land, Texas, United States, 77479Contact: Melissa Howell Melissa.Howell@usoncology.comPrincipal Investigator: Jorge Darcourt, MDTexas Oncology - TylerTyler, Texas, United States, 75702Contact: Shelly Maxfield Shelly.Maxfield@USOncology.comPrincipal Investigator: Nanna Sulai, MD UtahUniversity of Utah Huntsman Cancer InstituteSalt Lake City, Utah, United States, 84112Contact: Janna Espinosa janna.espinosa@hci.utah.eduPrincipal Investigator: Mei Wei, MD VirginiaVirginia Cancer SpecialistsFairfax, Virginia, United States, 22031Contact: Carrie Friedman Carrie.Friedman@USOncology.comPrincipal Investigator: Shruti Tiwari, MD About FLAMINGO-01 and GLSI-100 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 clinical sites from university-based hospitals and cooperative networks with plans to expand into Europe and 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 website here and clinicaltrials.gov here. 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 About Breast Cancer and HER2/neu Positivity 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. About Greenwich LifeSciences, Inc. 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 at www.greenwichlifesciences.com and follow the Company's Twitter at https://twitter.com/GreenwichLS. Forward-Looking Statement Disclaimer 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 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. Company ContactSnehal PatelInvestor RelationsOffice: (832) 819-3232Email: info@greenwichlifesciences.com Investor & Public Relations Contact for Greenwich LifeSciencesDave GentryRedChip Companies Inc.Office: 1-800-RED CHIP (733 2447)Email: dave@redchip.com

STAFFORD, Texas, April 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 following update on FLAMINGO-01 open label immune response data. FLAMINGO-01 Immune Response Data Summary The Company has analyzed the preliminary immune response data from FLAMINGO-01. Immune response data in both the HLA-A*02 treated and placebo arms and the third open label arm with all other HLA types (non- HLA-A*02), show that GLSI-100 is creating an immune response over time as the frequency of patients exhibiting an injection site reaction or GP2 Delayed-Type Hypersensitivity (DTH) skin test reaction as measured by induration or erythema is increasing with increased vaccinations. The number of patients experiencing an immune response increased over time from baseline through the 4th to 6th month vaccinations in both HLA-A*02 and non-HLA-A*02 arms.In addition, a baseline immune response to GP2 is being observed before any treatment with GP2 in both HLA-A*02 and non-HLA-A*02 arms. This result suggests that GP2 is a natural antigen, that may have been part of an immune response in the patient during prior trastuzumab or other treatments.These two general immune response findings, immune response at baseline and increasing immune response over time, were also observed in the Phase IIb clinical trial for HLA-A*02 only patients. These results confirm that the HLA prevalence, safety, and immune response in FLAMINGO-01 patients is trending as expected in both HLA arms.The Company recently filed patent claims for non-HLA-A*02 patients which may be solely owned by the Company separate from any prior license. These claims are also supported by binding prediction algorithms and in vitro binding experiments conducted by the Company. This represents an invention that was originated by the Company which could double the number of patients eligible for GP2 treatment to approximately 88,000 new patients per year in the US and Europe. The market potential using the drug prices per year of Kadcyla or Enhertu could be in the range of $8-10 billion per year.As mentioned in a prior press release, the non-HLA-A02 types that are most commonly being enrolled in FLAMINGO-01 include HLA-A*03, HLA-A*24, HLA-A*01, HLA-A*11, HLA-A*68, HLA-A*29, HLA-A*30, HLA-A*23, and HLA-A*33. Analysis of the open label data from FLAMINGO-01 has been conducted in a manner that maintains the study blind. The open label immune response data is based on the patients enrolled to date in FLAMINGO-01 and is thus preliminary. While comparing any preliminary FLAMINGO-01 data to the Phase IIb clinical trial data may be possible, these preliminary results are not a prediction of future results and the results at the end of the study may differ. CEO Snehal Patel commented, "We are very encouraged to see that the preliminary results from FLAMINGO-01 show immune responses in both HLA-A*02 and non-HLA-A*02 patients. We are now considering the merits of adding a randomized placebo arm for non-HLA-A*02 patients, transforming this current open label third arm into effectively a second pivotal and blinded Phase III trial. If successful, the Company could pursue approval for both HLA-A*02 and non-HLA-A*02 patients in similar time frames using independent or combined analysis of the two patient groups with the potential to double the market for GP2 to up to $10 billion in revenue per year." Mr. Patel added, "The Company may choose to expand its immune response analysis of GP2 specific T cells by sequencing the DNA of the T cells at baseline and after treatment with GP2. The T cell sequences can be compared to the immune response increases over time. Expansion into GP2 specific CAR-T cells could potentially become another platform technology to complement GP2 peptide treatment for non-responding higher risk patients. Blood samples have been collected at multiple timepoints for future T cell and immune response analysis." Previously Published Phase IIb Immune Response Data In the prospective, randomized, single-blinded, placebo-controlled, multi-center (16 sites led by MD Anderson Cancer Center) Phase IIb clinical trial of HLA-A*02 breast cancer patients, 46 HER2/neu 3+ over-expressor patients were treated with GLSI-100, and 50 placebo patients were treated with GM-CSF alone. After 5 years of follow-up, there was an 80% or greater reduction in cancer recurrences in the HER2/neu 3+ patients who were treated with GLSI-100, followed, and remained disease free over the first 6 months, which we believe is the time required to reach peak immunity and thus maximum efficacy and protection. The Phase IIb results can be summarized as follows: 80% or greater reduction in metastatic breast cancer recurrence rate over 5 years of follow-up compared to 20-50% reduction in recurrence rate by other approved productsPeak immune response at 6 months No reported serious adverse events attributable to treatmentWell-tolerated safety profile Full immunization was received in the Primary Immunization Series (PIS), which included the first 6 GLSI-100 injections over the first 6 months. The PIS elicited a potent immune response as measured by local skin tests and immunological assays. Further, booster injections given every 6 months prolonged the immune response, thereby providing longer-term protection. In the Phase IIb and three Phase I clinical trials, where 146 patients were treated, the GP2 immunotherapy was well tolerated, and there were no reported serious adverse events related to GLSI-100. The Phase IIb immune response data in HLA-A*02 only patients was published at AACR in 2021 with the following findings: GP2 immunotherapy generated GP2-specific immune responses leading to promising clinical benefit, thus supporting GP2’s mechanism of action.Immune responses to GP2 were measured over time using a CD8 T cell dimer binding assay (Dimer Binding Assay) and GP2 DTH skin tests. GP2 immunity peaked at 6 months in HER2 3+ patients after they completed their first 6 immunizations, as measured by the Dimer Binding Assay. The data also shows that for the 2.5 years that the immune response was measured, the immunity was sustained and remained above baseline, resulting in a reduction in metastatic breast cancer recurrences.Broad based immune response suggests that GP2 immunotherapy and Herceptin based products may also have the potential to treat low HER2 and other HER2 1-3+ expressing cancers in combination with trastuzumab or trastuzumab antibody drug conjugates. About FLAMINGO-01 and GLSI-100 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 clinical sites from university-based hospitals and cooperative networks with plans to expand into Europe and 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 website here and clinicaltrials.gov here. 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 About Breast Cancer and HER2/neu Positivity 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. About Greenwich LifeSciences, Inc. 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 at www.greenwichlifesciences.com and follow the Company's Twitter at https://twitter.com/GreenwichLS. Forward-Looking Statement Disclaimer 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 Form 10-K for the year ended December 31, 2023 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. Company ContactSnehal PatelInvestor RelationsOffice: (832) 819-3232Email: info@greenwichlifesciences.com Investor & Public Relations Contact for Greenwich LifeSciencesDave GentryRedChip Companies Inc.Office: 1-800-RED CHIP (733 2447)Email: dave@redchip.com

STAFFORD, Texas, March 27, 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 that its Board of Directors has extended the lock-up of the shares owned by the Company's directors, officers, and existing pre-IPO investors to March 31, 2026 which is approximately 66 months from date of the Company's IPO. During this period, current officers, directors and certain shareholders will not be able to sell their shares of the Company's common stock unless otherwise modified by the Board of Directors. After March 31, 2026, the quantity of these locked-up shares that can be sold daily and over various periods of time will be restricted unless otherwise modified by the Board of Directors. About FLAMINGO-01 and GLSI-100 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 clinical sites from university-based hospitals and cooperative networks with plans to expand into Europe and 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 website here and clinicaltrials.gov here. 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 About Breast Cancer and HER2/neu Positivity 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. About Greenwich LifeSciences, Inc. 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 at www.greenwichlifesciences.com and follow the Company's Twitter at https://twitter.com/GreenwichLS. Forward-Looking Statement Disclaimer 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 Form 10-K for the year ended December 31, 2023 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. Company ContactSnehal PatelInvestor RelationsOffice: (832) 819-3232Email: info@greenwichlifesciences.com Investor & Public Relations Contact for Greenwich LifeSciencesDave GentryRedChip Companies Inc.Office: 1-800-RED CHIP (733 2447)Email: dave@redchip.com