Greenwich LifeSciences (NASDAQ:GLSI), a clinical-stage biopharmaceutical company focused on the development of GP2, an immunotherapy to prevent breast cancer recurrences, has filed new patent claims that could significantly expand the addressable market for its lead candidate, GLSI-100.
The new claims are based on statistically significant immune response and recurrence-rate data derived from the company’s ongoing FLAMINGO-01 Phase III clinical trial.
According to the update provided to investors on April 7, 2026, the potential granting of these claims could expand the target GP2 market by 100%, increasing the estimated patient population from 44,000 to approximately 88,000 patients per year.
The invention, which is solely owned by Greenwich LifeSciences, focuses on specific dosing and combination strategies that may enable broader approvals across diverse patient subsets.
If the patent is granted following the standard prosecution period, it would extend the company's intellectual property protection for the GP2 platform through 2045.
To further validate the clinical signal, the company disclosed plans to begin sequencing GP2-specific T cells.
This deep-dive analysis is intended to provide a more granular understanding of the immune-response mechanism, potentially identifying biomarkers that could predict which patients are most likely to achieve a durable response to the immunotherapy.
FLAMINGO-01 is currently evaluating the safety and efficacy of GP2 in HER2/neu-positive breast cancer patients who have completed adjuvant trastuzumab-based therapy.
Previous Phase IIb data showed 0% cancer recurrences over five years of follow-up in the treated group, a result the company is working to replicate in its current large-scale registrational study.