Gossamer Bio has submitted its first New Drug Application to the U.S. Food and Drug Administration, seeking approval of seralutinib as a treatment for pulmonary arterial hypertension.

 

The application, submitted in September, is backed by the Phase 3 PROSERA trial, the Phase 2 TORREY study and additional supporting analyses, the company said Wednesday.

 

The filing marks a major regulatory step for Gossamer as it seeks to bring seralutinib to patients with pulmonary arterial hypertension, a serious form of pulmonary hypertension.

 

“Submitting our first NDA is a significant milestone for Gossamer and, more importantly, for patients living with PAH,” said Faheem Hasnain, Chairman, Co-Founder and Chief Executive Officer of Gossamer. “We are grateful to the patients, families, investigators and site staff who made PROSERA and TORREY possible, and to our employees for the work it took to reach this point.”

 

Gossamer said the NDA is supported by PROSERA as one adequate and well-controlled clinical investigation, with confirmatory evidence from TORREY and additional analyses.

 

The filing follows a June 2026 Pre-NDA Type B meeting between Gossamer and the FDA. According to the company, the FDA's official meeting minutes characterized the statistical significance and magnitude of the treatment effect observed in PROSERA as review issues rather than filing issues, while also providing feedback on the planned submission.

 

“This submission is the result of years of scientific rigor and the collective effort of colleagues across clinical development, biostatistics, regulatory affairs, manufacturing, quality and many other functions,” said Caryn Peterson, Chief Development Officer of Gossamer. “It brings us one step closer to delivering seralutinib as a potential new therapy for PAH patients who need better options.”

 

The filing does not mean seralutinib has been accepted for review or approved. The FDA will first determine whether the application is acceptable for filing following its initial review. Gossamer said that decision could come later this year.

 

The agency will ultimately assess the full application, including the efficacy and safety evidence, during its review.

 

Seralutinib is being developed by Gossamer for pulmonary arterial hypertension and pulmonary hypertension associated with interstitial lung disease. The company says its goal is to develop the drug as a potential new treatment for patients living with pulmonary hypertension.