PHILADELPHIA, April 13, 2026 /PRNewswire/ -- National plaintiffs' law firm Berger Montague PC announces a class action lawsuit against Gossamer Bio, Inc. (NASDAQ: GOSS) ("Gossamer" or the "Company") on behalf of investors who purchased or acquired Gossamer shares during the period from June 16, 2025 through February 20, 2026 (the "Class Period").
Investor Deadline: Investors who purchased or acquired Gossamer securities during the Class Period may, no later than June 1, 2026, seek to be appointed as a lead plaintiff representative of the class. To learn your rights, CLICK HERE.
Gossamer is a San Diego, California-based clinical-stage biopharmaceutical company focused on developing therapies for immuno-inflammatory and other diseases.
On February 23, 2026, the Company announced that the Phase 3 PROSERA study evaluating seralutinib for the treatment of pulmonary arterial hypertension (PAH) failed to meet its primary endpoint of improved six-minute walk distance (6MWD) at Week 24. Defendants attributed the results to unexpectedly strong placebo performance at Latin American sites.
Following this announcement, Gossamer's shares plunged more than 80% in a single day causing significant losses for investors.
If you are a Gossamer investor and would like to learn more about this action, CLICK HERE or please contact Berger Montague: Andrew Abramowitz at aabramowitz@bergermontague.com or (215) 875-3015, or Caitlin Adorni at cadorni@bergermontague.com or (267)764-4865.
About Berger Montague
Berger Montague is one of the nation's preeminent law firms focusing on complex civil litigation, class actions, and mass torts in federal and state courts throughout the United States. With more than $2.4 billion in 2025 post-trial judgments alone, the Firm is a leader in the fields of complex litigation, antitrust, consumer protection, defective products, environmental law, employment law, securities, and whistleblower cases, among many other practice areas. For over 55 years, Berger Montague has played leading roles in precedent-setting cases and has recovered over $50 billion for its clients and the classes they have represented. Berger Montague is headquartered in Philadelphia and has offices in Chicago; Malvern, PA; Minneapolis; San Diego; San Francisco; Toronto, Canada; Washington, D.C., and Wilmington, DE.
For more information or to discuss your rights, please contact:
Andrew Abramowitz
Berger Montague
(215) 875-3015
aabramowitz@bergermontague.com
Caitlin Adorni
Berger Montague
(267) 764-4865
cadorni@bergermontague.com
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SOURCE Berger Montague
