Greenwich LifeSciences Extends Lock-up of Directors and Officers to September 30, 2026

Rhea-AI Summary

Greenwich LifeSciences (Nasdaq: GLSI) said its Board extended the lock-up on shares held by directors, officers and certain pre-IPO investors to September 30, 2026, approximately 72 months from the IPO. During this period those holders cannot sell common stock unless the Board modifies the restriction.

After September 30, 2026, sales will be limited under a Board-controlled leak-out plan unless modified; the Board may instead end the 100% lock-up earlier and implement a 10b5-1 trading plan or other staged release options. Management said the lock-up is intended to align insiders with long-term investors and support the FLAMINGO-01 Phase III trial of GLSI-100.

Positive

• Lock-up extended to Sept 30, 2026 (~72 months)
• Lock-up designed to align insiders with long-term investors
• Lock-up intended to support FLAMINGO-01 Phase III trial

Negative

• Insiders cannot sell their shares until Sept 30, 2026
• Post-lock-up sales will be restricted by a leak-out plan
• Board retains discretion to modify or end the lock-up earlier

Key Figures

Price move 20.19% GLSI 24h price change prior to/around lock-up news

Trading volume 1,262,239 shares Today’s volume vs 20-day avg 435,808 shares

Volume multiple 2.9x Relative to 20-day average volume

52-week high $22.31 GLSI 52-week high price

52-week low $7.78 GLSI 52-week low price

Lock-up end date September 30, 2026 Extended lock-up for directors, officers, pre-IPO investors

Lock-up duration Approximately 72 months From IPO date to extended lock-up end

Illustrative leak-out percentages 95% / 99% vs 5% / 1% Example future split of locked vs sellable shares under plans

Market Reality Check

$19.47 Last Close

Volume Volume 1,262,239 vs 20-day avg 435,808 (about 2.9x typical activity) high

Technical Price $20.69 is trading above 200-day MA at $10.31

Peers on Argus

Peers show mixed moves (e.g., THTX +0.89%, CLYM +2.92%, MCRB -3.68%), indicating GLSI’s +20.19% move is stock-specific rather than sector-driven.

Historical Context

Date	Event	Sentiment	Move	Catalyst
Dec 22	Trial & strategy update	Positive	+2.7%	Updates on FLAMINGO-01 sites, DSMB reviews, and corporate funding strategy.
Dec 15	Preliminary efficacy data	Positive	-3.9%	Preliminary analysis showing ~80% reduction in recurrence in open-label arm.
Dec 08	Enrollment completion	Positive	+7.5%	Completion of enrollment in 250-patient non-HLA-A*02 open-label arm.
Dec 03	Global trial update	Positive	+5.1%	Global FLAMINGO-01 progress, >1,000 patients screened at ~140 sites.
Oct 09	Geographic expansion	Positive	-2.3%	Regulatory approval to expand FLAMINGO-01 trial footprint to Austria.

Pattern Detected

Recent GLSI news has mostly been trial-progress updates with generally positive reactions, though there are notable instances where positive clinical data coincided with short-term price declines.

Recent Company History

Over the past few months, GLSI has focused updates on the Phase III FLAMINGO-01 trial and corporate strategy. Key milestones included screening over 1,000 patients, completing enrollment in a 250-patient open-label arm, and reporting an estimated 80% recurrence-rate reduction in preliminary analysis. Corporate updates have highlighted trial design, global expansion, and funding via ATM. Today’s lock-up extension fits into this pattern of emphasizing long-term alignment around FLAMINGO-01 while prior news centered on operational and clinical progress.

Market Pulse Summary

The stock surged +19.8% in the session following this news. A strong positive reaction aligns with GLSI’s pattern of responding to governance and trial-related catalysts, as insiders and major holders extended their lock-up to September 30, 2026. The move came with volume about 2.9x the 20-day average, and the stock trading above its $10.31 200-day MA. While the lock-up can support perceptions of alignment, prior filings highlighted going-concern risks and ATM reliance, which could still influence longer-term sentiment.

Key Terms

phase iii medical

"a clinical-stage biopharmaceutical company focused on its Phase III clinical trial, FLAMINGO-01"

A Phase III trial is the late-stage clinical study that tests whether a medical treatment works and is safe in a large group of patients, often comparing it to standard care. Think of it as a final dress rehearsal or full-scale road test before regulators decide on approval; positive or negative results strongly influence a drug maker’s chance to sell the treatment, future revenue, and investment risk.

immunotherapy medical

"GLSI-100, an immunotherapy to prevent breast cancer recurrences"

Treatment that uses or enhances the body’s immune system to detect and fight disease, most often cancers or chronic infections; think of it as training or arming the body’s own soldiers to find and destroy targets. It matters to investors because successful immunotherapies can lead to high-value drug approvals, recurring revenue from long-term treatments, and changes in competitive dynamics, while failures or safety issues in clinical trials can materially affect company valuations.

lock-up financial

"extended the lock-up of the shares owned by the Company's directors, officers, and existing pre-IPO investors"

A lock-up is an agreement that prevents company insiders, early investors or employees from selling their shares for a set period after a public share offering. It matters to investors because it temporarily limits the number of shares available to trade—like a scheduled hold on extra inventory—and when that hold ends a large number of shares can enter the market, potentially putting downward pressure on the stock price and revealing insiders’ confidence in the company.

leak-out plan financial

"will be restricted under a leak-out plan unless otherwise modified by the Board of Directors"

A leak-out plan is an arrangement that lets a large shareholder or group gradually sell existing shares into the market on a set schedule rather than all at once. It matters to investors because it smooths the supply of stock, reducing the risk of a sudden price drop from a big sale and giving the market time to absorb the shares, much like releasing water through a tap instead of opening the valve all at once.

10b5-1 trading plan regulatory

"within a 10b5-1 trading plan over a specified period of time"

A 10b5-1 trading plan is a pre-arranged strategy that allows company insiders to buy or sell company stock at set times, regardless of their current knowledge about the company's situation. It acts like a scheduled appointment for trading, helping prevent the appearance of impropriety or insider trading. This plan provides a way for insiders to sell or buy shares in a controlled, transparent manner, offering reassurance to investors about fair trading practices.

AI-generated analysis. Not financial advice.

STAFFORD, Texas, Dec. 29, 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 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 September 30, 2026 which is approximately 72 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 September 30, 2026, 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.

CEO Snehal Patel commented, "This unprecedented 6 years lock-up is controlled by the Board and is designed to align the locked-up shareholders with the Company’s long term investors and to support the FLAMINGO-01 Phase III trial. The Board could choose to end the 100% lock-up at any time and could then implement a pre-determined leak-out plan and/or a 10b5-1 trading plan that allows for the organized independent selling of some of the locked-up shares by a third party over a specified period of time. One example of how the Board could proceed in the future might be to continue to keep 95% or 99% or a higher or lower percentage of the locked-up shares locked up for longer periods of time after September 30, 2026, while allowing 5% or 1% or a lower or higher percentage of the locked-up shares to be sold within a 10b5-1 trading plan over a specified period of time. Any interim analyses or strategic transactions, such as an acquisition or partnership, which could occur at any time, could also affect the Board’s lock-up and leak-out plans."

About FLAMINGO-01 Open Label Phase III Data

More than 1,000 patients have been screened with a current screen rate of approximately 600 patients per year. The 250 patient non-HLA-A*02 arm is now fully enrolled, where all patients received GLSI-100, which is 5 times more treated patients and recurrence rate data than the approximately 50 patients treated in the Phase IIb trial. The Primary Immunization Series (PIS), which includes the first 6 GLSI-100 injections over the first 6 months and is required to reach peak protection, is followed by 5 booster injections given every 6 months to prolong the immune response, thereby providing longer-term protection.

• In the non-HLA-A*02 arm, a preliminary analysis of recurrence rates after the PIS is completed shows an approximately 80% reduction in recurrence rate.
• This observation is trending similarly to the Phase IIb trial results and hazard ratio where HLA-A*02 patients were treated and where breast cancer recurrences were reduced up to 80% compared to a 20-50% reduction in recurrence rate by other approved products.
• The immune response at baseline prior to any GLSI-100 treatment, the increasing immune response during the PIS, and the safety profile of non-HLA-A*02 patients is trending similarly to the HLA-A*02 arms of FLAMINGO-01 and to the Phase IIb study.
  
  

Analysis of the open label data from FLAMINGO-01 has been conducted in a manner that maintains the study blind. The open label recurrence rate, immune response, and safety data is based on the patients enrolled to date in FLAMINGO-01 and the data provided by the clinical sites so far, which is not completed or fully reviewed, 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.

About GLSI-100 Phase IIb Study

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 with a peak immune response at 6 months and well-tolerated safety profile.
• The PIS elicited a potent immune response as measured by local skin tests and immunological assays.

About FLAMINGO-01 and GLSI-100

FLAMINGO-01 (NCT05232916) is a Phase III clinical trial designed to evaluate the safety and efficacy of Fast Track designated 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 are planned to be randomized to GLSI-100 or placebo, and up to 250 patients of other HLA types are planned to 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, 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.

Company Contact
Snehal Patel
Investor Relations
Office: (832) 819-3232
Email: info@greenwichlifesciences.com

Investor & Public Relations Contact for Greenwich LifeSciences
Dave Gentry
RedChip Companies Inc.
Office: 1-800-RED CHIP (733 2447)
Email: dave@redchip.com

FAQ

What lock-up change did Greenwich LifeSciences (GLSI) announce on December 29, 2025?

The Board extended the directors, officers and certain pre-IPO investors' lock-up to September 30, 2026 (about 72 months from the IPO).

How long will GLSI insiders be unable to sell shares under the new lock-up?

Current officers, directors and certain shareholders cannot sell their common stock until September 30, 2026 unless the Board modifies the restriction.

What happens to GLSI shares after the September 30, 2026 lock-up ends?

After that date, sales of locked-up shares will be limited under a Board-controlled leak-out plan unless the Board chooses another option.

Can the GLSI Board end the 100% lock-up before September 30, 2026?

Yes; the Board could end the 100% lock-up earlier and implement a leak-out or a 10b5-1 trading plan for staged selling.

Why did Greenwich LifeSciences extend the lock-up to September 30, 2026?

Management said the extended lock-up is intended to align locked-up shareholders with long-term investors and to support the FLAMINGO-01 Phase III trial of GLSI-100.