Gossamer Bio's seralutinib fails critical Phase 3 trial, sending stock into freefall

Gossamer Bio's drug candidate seralutinib has failed a key Phase 3 trial, putting the company's entire development programme at risk. The setback triggered a sharp drop in its stock price, which now trades at around $0.42 per share. Investors and analysts are awaiting further clarity from an upcoming meeting with US regulators.

The failure of seralutinib (GB002) in the PROCERA Phase 3 study marked a major blow for Gossamer Bio. Earlier clinical trials had shown promise for treating pulmonary arterial hypertension (PAH), but the latest results missed their primary goal. Final data from the study are not expected until February 2026, according to analyst reports.

Analysts have reacted strongly to the news. Cantor Fitzgerald downgraded the company's stock from 'Overweight' to 'Neutral', while firms like Barclays and Wedbush had already cut their outlooks in late February. Current price targets vary widely, from as low as $0.30 to as high as $15.00, with an average of $5.43. Opinions remain split, with two analysts recommending selling and four still advising to buy.

The company's market value has shrunk to $99 million, down roughly 86% since January. In response, Gossamer Bio has scheduled a 'Type C' meeting with the US Food and Drug Administration (FDA) in June to explore potential paths forward. Concrete outcomes from that discussion are expected by July, while the next quarterly financial report is due on May 12.

The failed trial leaves seralutinib's future uncertain, with Gossamer Bio now relying on regulatory feedback to determine next steps. Shareholders will watch closely for updates from the June FDA meeting and the May earnings report. For now, the company's stock remains under heavy pressure, reflecting deep concerns about its pipeline.