---
schema_version: "secwatch.filing_event.v1"
accession: "0001728117-26-000064"
form_type: "8-K"
ticker: "GOSS"
cik: "0001728117"
company_name: "Gossamer Bio, Inc."
filed_at: "2026-07-27T20:01:09+00:00"
generated_at: "2026-07-27T20:02:16.481934+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Gossamer Bio to submit NDA for seralutinib in PAH in Sep 2026; reacquires worldwide rights from Chiesi

## Summary
- FDA Pre-NDA meeting minutes allow NDA submission based on Phase 3 PROSERA plus confirmatory evidence; submission planned for September 2026.
- Gossamer reacquired worldwide rights to seralutinib from Chiesi; Chiesi pays $5M to Gossamer, no upfront cash from Gossamer; Gossamer retains majority of global economics.
- Preliminary cash, cash equivalents and marketable securities ~$57M as of June 30, 2026.
- Stockholders approved convertible note exchange (reduced debt by ~$115.9M) and authorized reverse stock split to support Nasdaq compliance.
- If NDA accepted, FDA approval decision possible in Q3 2027.

## SEC filing metadata
- accession: 0001728117-26-000064
- form_type: 8-K
- ticker: GOSS
- cik: 0001728117
- company_name: Gossamer Bio, Inc.
- filed_at: 2026-07-27T20:01:09+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 1.01, 1.02, 2.02, 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1728117/000172811726000064/0001728117-26-000064-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1728117/000172811726000064/goss-20260723.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001728117-26-000064
- JSON: https://secwatch.observer/filing/0001728117-26-000064.json
- Plain text: https://secwatch.observer/filing/0001728117-26-000064.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.