GLSI Shares Rise 4% on Vaccine Data

Shares of Greenwich LifeSciences (NASDAQ:GLSI) jumped over 4% in pre‑market trading on 20 April 2026 after trial data release.
The GLSI‑100 vaccine in the late‑stage FLAMINGO‑01 study showed immune response rise to 20.4% from 5.2% in HLA‑A02‑negative patients.
Breast‑cancer recurrence in this subgroup fell by up to 80% after the initial injection series, matching earlier findings.
The company may seek regulatory approval for both genetic subgroups pending final trial outcomes.