Gossamer Bio shares crash after lung disease drug fails late stage trial
Gossamer Bio shares crashed 80% today after its lung drug failed a late-stage trial. The firm still plans to discuss the results with federal regulators.
Insights:
Gossamer Bio, Inc. , a biotechnology firm based in the United States 
US, reported on February 23, 2026, that its lead program, the inhaled investigational drug seralutinib, failed to meet the primary efficacy threshold in a late-stage (pivotal) trial. The study was designed to treat pulmonary arterial hypertension, but it did not achieve the statistical threshold for improving the six-minute walking distance (the trial's primary endpoint). This trial failure directly affects the development and regulatory prospects of Gossamer's lead program.
US, reported on February 23, 2026, that its lead program, the inhaled investigational drug seralutinib, failed to meet the primary efficacy threshold in a late-stage (pivotal) trial. The study was designed to treat pulmonary arterial hypertension, but it did not achieve the statistical threshold for improving the six-minute walking distance (the trial's primary endpoint). This trial failure directly affects the development and regulatory prospects of Gossamer's lead program.
