The investigation centers on the company’s Phase 3 PROSERA study, which evaluated the drug seralutinib. According to a federal securities lawsuit, Gossamer Bio failed to disclose significant flaws in the study’s design, specifically regarding its inability to control for placebo responses at clinical sites in Latin America. These omissions allegedly allowed the company to present an inflated view of the trial’s strength, leading investors to purchase shares at artificially elevated prices.

Investors who acquired GOSS securities prior to June 16, 2025, are being urged to come forward. Kuehn Law, which operates on a contingency basis covering all case costs, is seeking to determine the extent of the impact on shareholders. Those interested in participating in the potential litigation are instructed to contact Sophia Anne Silayan to discuss their legal standing and the enforcement of shareholder rights.