Greenwich LifeSciences Extends Lock-up of Directors and Officers to January 31, 2027

STAFFORD, Texas, Aug. 10, 2026 (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 Fast Track designated 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 January 31, 2027 which is approximately 76 months from the 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 January 31, 2027, the quantity of these locked-up shares that can be sold daily and over various periods of time will be restricted under a leak-out plan unless otherwise modified by the Board of Directors.

The Board could choose to end all or a small percentage of the 100% lock-up at any time for any reason, including prior to any data announcements, interim analyses, strategic transactions, such as an acquisition or partnership, or financial transactions, such as royalty or strategic investor transactions that provide a potential bridge to commercialization. The Board could also choose to implement a pre-determined leak-out plan and/or a 10b5-1 selling program at any time for any reason that allows for the organized independent selling of some of the locked-up shares by a third party over a specified period of time. Such decisions may or may not be announced at the time of the board's decision.

CEO Snehal Patel commented, "We attended and presented at the BIO conference in June 2026 and plan to attend the BIO-Europe conference later this year, where strategic and financing transactions can be originated or concluded. With the further derisking of the Phase III clinical trial, more than doubling of enrollment and event rate, interest from leading clinicians and hospitals in up to 200 sites in the US and Europe, screening of over 1,500 patients, and the transformation of the interim analysis into a big pharma like study similar in design to recent large breast cancer studies, we are expecting a continued up-tick in the quantity and seriousness of such discussions."

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, 2025, 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 Contact Snehal Patel Investor Relations Office: (832) 819-3232 Email: [email protected]

Investor & Public Relations Contact for Greenwich LifeSciences Dave Gentry RedChip Companies Inc. Office: 1-800-RED CHIP (733 2447) Email: [email protected]

Source: Greenwich LifeSciences, Inc. Released August 10, 2026