Gossamer Bio Reports $170.4M 2025 Net Loss, PROSERA Shows 13.3m Walk Improvement
Full-year 2025 net loss was $170.4 million ($0.75 per share) versus $56.5 million ($0.25), with R&D spend rising to $174.1 million. The Phase 3 PROSERA trial delivered a 13.3-meter six-minute walk gain at p=0.0320, prompting plans for a June FDA Type C meeting.
1. Phase 3 PROSERA Topline Results
In February 2026, the PROSERA Phase 3 trial showed inhaled seralutinib improved six-minute walk distance by 13.3 meters (p=0.0320), missing the 0.025 alpha threshold. High-risk (REVEAL Lite 2 ≥6) and CTD-PAH subgroups saw placebo-adjusted gains of 20.0 meters (nominal p=0.0207) and 37 meters (nominal p=0.0104), while NT-proBNP fell by 120.4 ng/L (nominal p=0.0002).
2. Cash Runway and Corporate Actions
As of December 31, 2025, cash, cash equivalents and marketable securities totaled $136.9 million, expected to fund operations into Q1 2027. The company enacted a workforce reduction and cost-containment measures to align resources with the seralutinib program, while maintaining modest spend on RT234.
3. 2025 Financial Performance
Full-year R&D expenses rose to $174.1 million from $138.5 million, and G&A expenses increased to $37.6 million from $36.1 million. Net loss for 2025 reached $170.4 million ($0.75 per share), compared with a $56.5 million loss ($0.25 per share) in 2024.
4. Regulatory and Strategic Plans
The company has paused enrollment in the Phase 3 SERANATA study for PH-ILD to analyze regional placebo variability and will seek a Type C meeting with FDA, potentially in June 2026, to discuss PROSERA results and next steps for seralutinib’s development.