The Gross Law Firm notifies investors that a class action has commenced in the United States District Court for the Southern District of California on behalf of shareholders of Gossamer Bio, Inc. who purchased securities between June 16, 2025 and February 20, 2026.
According to the complaint, defendants provided overwhelmingly positive statements to investors while, at the same time, disseminating false and misleading statements and/or concealing material adverse facts concerning the study design for the Company’s Phase 3 PROSERA study, particularly, controlling for the placebo response at the Latin American testing sites. On February 23, 2026, Gossamer published a press release and hosted a Special Call announcing topline results for its Phase 3 PROSERA study, which failed to meet the primary endpoint of improved six-minute walk distance (6MWD) at Week 24, with a +13.3 meter placebo-adjusted gain (p-0.0320) failing to meet the required 0.025 alpha threshold. Gossamer attributed this miss to patients at Latin American sites performing particularly well on placebo due to enrollment of a heavily-treated lower-risk population. Following this news, the price of Gossamer’s common stock declined from a closing market price of $2.13 per share on February 20, 2026 to $0.42 per share on February 23, 2025, a decline of over 80% in the span of just a single day.
If you wish to choose counsel to represent you and the class, you must apply to be appointed lead plaintiff and be selected by the Court. The lead plaintiff will direct the litigation and participate in important decisions including whether to accept a settlement for the class in the action. The lead plaintiff will be selected from among applicants claiming the largest loss from investment in the respective securities during the class periods. Members of the class will be represented by the lead plaintiff and counsel chosen by the lead plaintiff. No class has yet been certified in the above action. Appointment as Lead Plaintiff is not required to partake in any recovery.
Shareholders have until June 1, 2026 to request that the court appoint them lead plaintiff.
To receive more information, please fill out the form.
