Greenwich Lifesciences Advances GLSI-100 With FDA Approval Of Commercial Supply

Greenwich LifeSciences announced that the U.S. FDA has approved the use of the first commercially manufactured lot of its GP2 drug product for the ongoing Phase III FLAMINGO-01 trial of GLSI-100, an immunotherapy designed to prevent breast cancer recurrence. The GP2 active ingredient was produced in three commercial-scale lots in 2023 at an FDA-approved facility, enough to supply roughly 200,000 doses, while the first finished vialed commercial lot was completed in 2024. Stability programs were initiated for all four lots, and following regulatory review, the FDA has now cleared the initial vialed lot for clinical use in the U.S.

The company emphasized that commercial manufacturing data from three lots will be essential for a future Biologics License Application (BLA) submission in the U.S., along with regulatory filings in other regions. Greenwich plans to manufacture at least two additional finished GP2 lots so that both clinical and production data can be evaluated by the FDA’s biologics division ahead of a potential marketing approval. If granted, GLSI-100 could benefit from up to 12 years of market exclusivity under current U.S. law.

CEO Snehal Patel commented, "With our manufacturing investments in 2023 and 2024, and now the FDA's review and approval to use the first commercial lot of finished GP2 vials in FLAMINGO-01, we have taken major steps to further de-risk the filing of a BLA in the US. We plan to start using these new GP2 vials in the coming weeks at all 40 US sites. We have 3 years of stability data to support the GP2 vial expiration date which may translate to the commercial expiration date of GP2 vials."

FLAMINGO-01 screening has now surpassed 1,000 patients, with enrollment continuing at a rate of about 600 patients per year. The study’s 250-patient non-HLA-A*02 cohort has been fully enrolled, with all participants receiving GLSI-100, providing five times more treated patients and recurrence data than the company’s earlier Phase IIb study.

Mr. Patel further added, "We look forward to submitting the same manufacturing data to regulatory agencies in Europe, the United Kingdom, and Canada. The objective is to manufacture GP2 and to conduct FLAMINGO-01 at the 150 leading clinical sites in the US and Europe in a manner that provides for an efficient transition to product launch and commercial sales if GLSI-100 is approved."

Patients in the trial receive an initial Primary Immunization Series of six injections over six months to achieve peak immune protection, followed by booster doses every six months to sustain the response over time. Greenwich said the structure of the dosing regimen is designed to deliver long-term immunity and support the therapy’s potential as a preventative option for breast cancer recurrence.