Greenwich LifeSciences Files New GP2 Patent Claims That Could Double Its Breast Cancer Market

Greenwich LifeSciences, Inc. (Nasdaq: GLSI) has filed new patent claims for its breast cancer immunotherapy GLSI‑100 (GP2 + GM‑CSF), based on statistically significant immune‑response and recurrence‑rate data from the open‑label arm of its Phase III FLAMINGO‑01 trial. The company believes these claims show clinical benefit in non‑HLA‑A02 patients as well as HLA‑A02 patients, which could expand the eligible market by 100% to roughly 88,000 new patients per year in the U.S. and Europe and lift GP2’s revenue potential to as much as 10 billion dollars annually if approved.

Data support enrollment regardless of HLA type

In FLAMINGO‑01, more than 1,000 patients have been screened, and the 250‑patient non‑HLA‑A02 arm—where all patients received GLSI‑100—is now fully enrolled, providing about five times more treated‑patient and recurrence data than the earlier Phase IIb trial. The company reports that immune responses and recurrence‑rate trends in non‑HLA‑A02 patients resemble those seen in HLA‑A*02 patients and in the Phase IIb trial, where GP2 reduced breast cancer recurrences by up to 80% versus the 20–50% reductions seen with other approved products.

Patent term could run to 2045

If granted after full prosecution, the new patent could protect GP2‑related inventions through 2045, and Greenwich notes that the invention is solely owned by the company. Management also plans to deepen its immune‑response work by sequencing GP2‑specific T cells at baseline and after treatment, linking T‑cell clonotypes to changes in immunity and clinical outcomes over time.

FLAMINGO‑01 now enrolling both HLA‑A02 and non‑A02

Following FDA review of protocol changes, U.S. enrollment in FLAMINGO‑01 now includes both HLA‑A02 and non‑HLA‑A02 patients in the same randomized arms, boosting statistical power for a combined analysis. If the trial reads out positively, Greenwich expects to have the option to seek approval in both HLA‑A02 and non‑A02 populations, leveraging the broader patent claims to support a much larger commercial label.

Investor angle for GLSI

For GLSI shareholders, the new patent strategy is an attempt to lock in long‑dated exclusivity while materially enlarging the addressable market for GP2 beyond HLA‑restricted patients. The upside hinges on FLAMINGO‑01 maintaining its favorable efficacy and safety trends and regulators accepting a combined HLA‑A02 / non‑A02 indication; risks include clinical trial execution, patent prosecution outcomes, and Greenwich’s ability to finance development through potential approval.