Gossamer Bio, Inc. announced plans to submit a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) for its flagship drug candidate, seralutinib, in September 2026.

Regulatory Updates

The upcoming submission follows a Pre-NDA Type B meeting held with the FDA in mid-June and the receipt of official meeting minutes. According to Gossamer, the FDA characterized the degree of statistical significance and treatment effect observed in its Phase 3 PROSERA study as review issues rather than filing issues.

The company intends to submit the application using the Phase 3 PROSERA trial supported by confirmatory evidence from its Phase 2 TORREY trial and related analyses. If the FDA accepts the submission for filing, seralutinib—an inhaled inhibitor targeting PDGFR, CSF1R, and c-KIT for the treatment of pulmonary arterial hypertension (PAH)—could be eligible for an approval decision in the third quarter of 2027.

Corporate Updates

Gossamer announced it has terminated its Collaboration and License Agreement with Chiesi, reacquiring full worldwide development and commercialization rights for seralutinib. The move consolidates global control of manufacturing, pricing, and commercial strategy under Gossamer while eliminating the previous 50/50 U.S. profit-sharing structure.

Under the terms of the termination, Chiesi will pay Gossamer a one-time fee of $5 million to settle outstanding obligations, including costs from the second quarter of 2026. Gossamer paid no upfront cash to reclaim the rights. In exchange, Chiesi will receive specified regulatory and commercial milestone payments, along with a capped royalty on future worldwide net sales.

Original reporting: Tampa Free Press — read the source article.