Greenwich LifeSciences Announces Use of Commercially Manufactured GP2 in FLAMINGO-01
Rhea-AI Summary
Greenwich LifeSciences (Nasdaq: GLSI) reported that the first commercial lot of GP2 vials was approved by the FDA for use in FLAMINGO-01 and that all ~40 US sites were supplied and began treating patients with commercially manufactured GP2.
The company noted prior manufacture of GP2 active ingredient (sufficient for ~200,000 doses), ongoing stability programs, submission of data to other regulators, and plans to target 500,000–1,000,000 vials per year capacity.
Positive
- FDA approval of first commercial GP2 vial lot for FLAMINGO-01
- Commercial distribution to ~40 US sites with immediate patient treatment
- ~200,000 doses worth of GP2 active ingredient previously manufactured
- Plans to scale to 500,000–1,000,000 vials annual capacity
- Clinical supply and operations team internalized in Q4 2025
Negative
- Commercial approval still pending with European, UK, and Canadian regulators
- Current commercial lots require ongoing stability programs and monitoring
Market Reaction – GLSI
Following this news, GLSI has gained 5.09%, reflecting a notable positive market reaction. Our momentum scanner has triggered 5 alerts so far, indicating moderate trading interest and price volatility. The stock is currently trading at $28.10. This price movement has added approximately $18M to the company's valuation.
Data tracked by StockTitan Argus (15 min delayed). Upgrade to Silver for real-time data.
Key Figures
Market Reality Check
Peers on Argus
GLSI was up 0.75% while only one momentum peer (AGEN) screened and moved down 2.26%. Other close peers showed mixed moves, suggesting this update is being treated more as stock-specific than part of a broad sector move.
Historical Context
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| Mar 03 | Trial enrollment update | Positive | -0.5% | Reported ~33% increase in FLAMINGO-01 patient screening rate. |
| Feb 24 | Conference abstracts | Positive | +9.6% | Two GLSI-100 abstracts accepted for AACR 2026 presentations. |
| Jan 27 | Cash and financing update | Positive | +9.6% | ATM proceeds exceeded ~<b>$9.5M</b> 2025 burn, boosting cash levels. |
| Jan 22 | FDA manufacturing approval | Positive | +5.7% | FDA approved first commercially manufactured GP2 vial lot for FLAMINGO-01. |
| Dec 29 | Insider lock-up extension | Positive | +19.8% | Extended insider lock-up to <b>Sep 30, 2026</b> to support trial focus. |
Recent GLSI news has generally drawn positive price reactions, with four of the last five items trading higher the next day and one small negative reaction.
Over the last few months, Greenwich LifeSciences has focused investor attention on the Phase III FLAMINGO-01 trial and related execution. Updates have highlighted higher screening rates, acceptance of abstracts at the AACR 2026 meeting, and FDA approval to use commercially manufactured GP2 vials at 40 US sites. Capital updates showed use of an ATM to fund the trial despite prior going-concern language. The current announcement continues this theme of operational readiness and commercial-scale manufacturing.
Market Pulse Summary
The stock is up +5.1% following this news. A strong positive reaction aligns with GLSI’s pattern of favorable responses to operational FLAMINGO-01 updates, such as prior FDA approval of commercial GP2 vials and AACR abstract news, which saw multiple 5%+ moves. The expanded commercial manufacturing capacity and site supply strengthen the trial’s execution story, but investors have also seen ATM usage and going-concern language in past filings, which can become overhangs if enthusiasm over manufacturing progress fades.
Key Terms
immunotherapy medical
Phase III medical
FDA regulatory
AI-generated analysis. Not financial advice.
STAFFORD, Texas, March 16, 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 GLSI-100, an immunotherapy to prevent breast cancer recurrences, today provided the following update on the use of commercially manufactured GP2 in FLAMINGO-01.
All US Sites Treating Patients with Commercially Manufactured GP2
The Company previously announced that the first three commercial lots of GP2 active ingredient were manufactured in 2023 in an approved commercial facility, which could be used to prepare approximately 200,000 doses of GP2. In 2024, the first of three commercial lots filling GP2 into vials for commercial sale or for clinical use was manufactured in a commercial facility. In addition, drug stability programs were initiated for all four lots. Data on these commercial lots was recently submitted to the FDA, and after review, the first commercial lot of GP2 vials was approved for use in FLAMINGO-01 in the US.
Within weeks following the FDA review, all approximately 40 US sites were supplied with commercially manufactured GP2 vials and these sites began treating patients with these vials immediately. We were able to efficiently distribute the GP2 vials and communicate with the US pharmacists working with our warehouse partners and through our clinical team, which we internalized in Q4 2025.
CEO Snehal Patel commented, "We have started to submit the same manufacturing information to European, UK, and Canadian regulators so that commercially manufactured GP2 can be approved for use by all approximately 160 sites participating in FLAMINGO-01. We are also planning to manufacture additional vials of GP2, seeking a capacity of 500,000 to 1 million vials of GP2 per year, and to make larger lots of GP2 active ingredient to build inventory for a potential commercial launch."
About FLAMINGO-01 Open Label Phase III Data
More than 1,000 patients have been screened with a current screen rate of approximately 800 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 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
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
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
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 did GLSI announce about FDA approval for GP2 in FLAMINGO-01 on March 16, 2026?
How many US FLAMINGO-01 sites are using commercially manufactured GP2 (GLSI)?
What manufacturing capacity does GLSI plan for GP2 after the March 16, 2026 update?
How much GP2 active ingredient had been manufactured before the March 16, 2026 announcement?
Will commercially manufactured GP2 be available outside the US for FLAMINGO-01 (GLSI)?
