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Greenwich LifeSciences, Inc. reports developments as a clinical-stage biopharmaceutical company focused on FLAMINGO-01, a Phase III clinical trial evaluating GLSI-100 as an immunotherapy intended to prevent breast cancer recurrences. GLSI-100 combines the GP2 peptide with GM-CSF and is described by the company as a Fast Track designated program.
Recurring news includes FLAMINGO-01 clinical-site activity, oncology conference abstracts and posters, open-label immune-response and recurrence-rate data, patent-claim updates tied to GP2, at-the-market equity financing activity, and SEC reporting or Nasdaq compliance matters related to periodic filings.
Greenwich LifeSciences (Nasdaq: GLSI) reported UK regulatory approval to expand its Phase III FLAMINGO-01 trial of GLSI-100, an immunotherapy aimed at preventing breast cancer recurrences. The approval enables adding an estimated 5-10 UK sites to the approximately 170-180 sites already approved in the US and Europe and includes collaboration with leading cancer center The Royal Marsden, whose principal investigator will also serve as UK national principal investigator and join the Steering Committee.
Open-label FLAMINGO-01 data show more than 1,500 patients screened and full enrollment of the 250-patient non-HLA-A*02 arm, in which all patients received GLSI-100. A preliminary analysis after the six-dose Primary Immunization Series indicates an approximately 70-80% reduction in recurrence rate, with immune response and safety trends similar to prior Phase IIb results, where GLSI-100 reduced metastatic breast cancer recurrences by 80% or more over five years in HER2/neu 3+ patients. The company states these Phase III data are preliminary, incomplete and not predictive of final outcomes.
Greenwich LifeSciences (Nasdaq: GLSI) reported multiple clinical and financial updates on its Phase III breast cancer trial FLAMINGO-01 evaluating GLSI-100. The May 2026 Data Safety Monitoring Board recommended the study continue unchanged. Following FDA and EMA review, the trial design has been expanded and amended, including combining all HLA types in the blinded arms, which is expected to increase enrollment 2.22x by allowing non-HLA-A*02 patients (about 55% of the population) to enter randomization.
The company has screened over 1,500 patients across roughly 170-180 sites in 11 countries and fully enrolled the 250-patient non-HLA-A*02 open-label arm. Preliminary analysis after the primary immunization series suggests a 70-80% reduction in recurrence rate (hazard ratio 0.2-0.3). Trial redesign targets a hazard ratio of 0.55 with up to 2,000 patients and interim analyses at 28 and 56 events. Greenwich reported an annual cash burn of about $7 million in 2023-2024, $10 million in 2025, and expects approximately $2 million burn in Q2 2026, with an estimated June 30, 2026 cash balance of $8.9 million; these financial figures are preliminary and unaudited.
Greenwich LifeSciences (Nasdaq: GLSI) reported that the European Medicines Agency has approved combining both HLA-A*02 and non-HLA-A*02 patients in the randomized arms of its Phase III FLAMINGO-01 trial of GLSI-100 to prevent breast cancer recurrences.
All 170-180 clinical sites in the US and Europe now operate under a unified protocol and may continue enrollment to the first interim analysis, with data still analyzable by individual HLA types. According to Greenwich LifeSciences, US protocol changes allowing combined enrollment more than doubled pivotal-arm enrollment rates and made non-HLA-A*02 patients, about 55% of the population, eligible after long waits, creating a pathway to seek approval in both HLA groups and to use increased statistical power from a combined analysis.
Greenwich LifeSciences (Nasdaq: GLSI) reported that the European Medicines Agency has approved use of its commercially manufactured GP2 lot in the Phase III FLAMINGO-01 trial. FDA had already allowed this lot in the US, where 40-50 sites are treating patients. Global sites have risen from 160 to about 170-180, all expected to use the same GP2 lot.
Greenwich LifeSciences (Nasdaq: GLSI) reported new open-label immune response data from the non-HLA-A*02 arm (n=247) of the Phase III FLAMINGO-01 trial of Fast Track GLSI-100 in HER2-positive breast cancer.
Erythema ISRs increased from 20.2% after dose 1 to 55.3% after doses 4–6, and induration from 14.9% to 34.6% (both McNemar p<0.001). The company links these immune responses and earlier preliminary data suggesting a 70–80% recurrence reduction in this arm to GLSI-100’s proposed mechanism of action. The trial remains ongoing and final results may change.
Greenwich LifeSciences (Nasdaq: GLSI) updated investors on its delayed Form 10-K for the year ended December 31, 2025, which is still under audit by a new auditor and includes the 2024 audit from the prior auditor.
The company links accounts payable adjustments to its global Phase III FLAMINGO-01 trial and higher-than-expected European screening and enrollment. It reports unaudited cash of about $10.5 million as of March 31, 2026, exceeding 2025 net cash used in operations of approximately $9.9 million, and says over 75% of 2025 accounts payable has been retired.
Greenwich LifeSciences (Nasdaq: GLSI), a clinical-stage biopharma company running the Phase III FLAMINGO-01 trial of Fast Track-designated GLSI-100, received a Nasdaq notice on May 20, 2026.
The company is not in compliance with Nasdaq Listing Rule 5250(c)(1) due to a late Form 10-Q for Q1 2026, but there is no immediate effect on GLSI’s Nasdaq Capital Market listing or trading.
Greenwich LifeSciences (Nasdaq: GLSI) said its Form 10-K for fiscal 2025 remains under audit; auditors expect to complete audits before the end of May and file alongside the Form 10-Q for period ending March 31, 2026. Final adjustments focus on accounts payable tied to its global Phase III trial. The company reported an unaudited cash balance of ~$10.5 million as of March 31, 2026, subject to change after the Q1 financial review.
Greenwich LifeSciences (Nasdaq: GLSI) announced that an abstract has been accepted for publication and poster presentation at the 2026 ASCO Annual Meeting, May 28–June 2, 2026. The full abstract and poster will be available on June 1, 2026. The submission presents preliminary injection site reaction immune response data from the non-HLA-A*02 open-label arm of Phase III FLAMINGO-01 evaluating Fast Track designated GLSI-100. Management said the abstract is co-authored with the FLAMINGO-01 Steering Committee. The company also plans to attend upcoming ESMO Breast, BIO partnering, and investor conferences.
Greenwich LifeSciences (Nasdaq: GLSI) received a notice from Nasdaq on April 16, 2026, for noncompliance with Nasdaq Listing Rule 5250(c)(1) because it has not yet filed its Annual Report on Form 10-K for the fiscal year ended December 31, 2025.
The notice does not affect the current listing or trading of GLSI common stock. The company says it will file the Form 10-K as soon as possible, coordinating with two auditors who are each responsible for their respective periods in 2024 and 2025.