Seralutinib New Drug Application Submitted to the FDA for Pulmonary Arterial Hypertension – Gossamer Bio

Gossamer Bio, Inc. announced that it submitted a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) in September 2026 for seralutinib for the treatment of pulmonary arterial hypertension (PAH). This is the Company’s first NDA submission.

The NDA is supported by the Phase 3 PROSERA Study as one adequate and well-controlled clinical investigation, together with confirmatory evidence from the Phase 2 TORREY Study and supportive analyses. The NDA submission follows the Company’s Pre-NDA Type B meeting with the FDA in June 2026 and the FDA’s official written meeting minutes, in which the FDA characterized the degree of statistical significance and the magnitude of the treatment effect observed in PROSERA as review issues rather than filing issues, and provided feedback on the format and content of the planned submission.

“Submitting our first NDA is a significant milestone for Gossamer and, more importantly, for patients living with PAH.” – 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.”

“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.” – 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 FDA will determine whether to accept the NDA for filing following its initial review of the application, which the Company anticipates could occur later this year. The acceptability of the individual elements of the application, including the efficacy and safety evidence, will be determined by the FDA during its review of the complete NDA.