GOSS FINAL DEADLINE ALERT: Gossamer Bio Investors With Losses May Seek to Lead the Class Action After Executives Allegedly Concealed Placebo Risk: HBSS

A securities class action lawsuit has been filed against Gossamer Bio (GOSS) alleging executives concealed placebo response risks in the Phase 3 PROSERA trial for seralutinib. The trial failed to meet its primary endpoint on February 23, 2026, causing an 80% stock price decline. The complaint claims management misled investors about trial design and patient recruitment despite knowing of significant placebo effects, particularly at Latin American sites.