Law Firm Seeks Gossamer Investors to Lead Securities Suit Over Failed Phase 3 Trial

Overview

• Gossamer disclosed that its Phase 3 PROSERA study missed the trial’s primary six‑minute walk distance endpoint and the stock plunged, triggering investor losses that form the basis of the suit.
• A plaintiff firm has issued a public notice inviting affected shareholders to participate and to seek lead‑plaintiff status before a June lead‑plaintiff deadline, which is a routine step in early securities litigation.
• The complaint alleges that Latin American trial sites enrolled largely heavily treated, lower‑risk patients who produced an unusually large placebo response that diluted the overall treatment effect.
• No class has been certified and no defendant has been found liable; the case is at the pre‑certification, investor‑recruitment stage and the allegations remain unproven.
• If a lead plaintiff is chosen, discovery could probe site‑level recruitment, monitoring and corporate statements about trial prospects, with possible implications for investor claims and regulatory or listing questions.