Gossamer Bio’s Seralutinib Phase 3 PROSERA Improves 6MWD by 13.3 m but Misses Primary Endpoint
Gossamer Bio’s Phase 3 PROSERA trial of seralutinib in PAH showed a placebo-adjusted 13.3 m improvement in six-minute walk at Week 24 but narrowly missed its 0.025 alpha with p=0.0320. Secondary endpoints showed NT-proBNP reduction and favorable safety in patients on triple/quadruple therapies, and SERANATA enrollment is paused for placebo-response review.
1. Topline PROSERA Results
Gossamer Bio’s Phase 3 PROSERA trial evaluated seralutinib in pulmonary arterial hypertension. It achieved a placebo-adjusted improvement of 13.3 meters in six-minute walk distance at Week 24 but narrowly missed the prespecified alpha of 0.025 with a p-value of 0.0320.
2. Secondary Endpoint Outcomes
The trial showed a significant reduction in NT-proBNP levels, indicating decreased cardiac stress, and seralutinib was generally well tolerated in a heavily pre-treated population in which 55% of participants were on triple or quadruple background therapies.
3. Next Steps and SERANATA Pause
Gossamer Bio plans to meet with the FDA to discuss potential regulatory pathways. Meanwhile, the company has paused enrollment in the SERANATA study to analyze regional discrepancies in placebo responses observed during the PROSERA trial.