---
schema_version: "secwatch.filing_event.v1"
accession: "0001728117-23-000030"
form_type: "8-K"
ticker: "GOSS"
cik: "0001728117"
company_name: "Gossamer Bio, Inc."
filed_at: "2023-04-03T23:59:59+00:00"
generated_at: "2026-06-17T07:07:52.846057+00:00"
event_type: "regulatory"
sentiment: "negative"
materiality_score: 0.9
calibrated_materiality_score: 0.9
confidence: "high"
source: SEC EDGAR
---

# Gossamer Bio discontinues GB5121 after FDA partial clinical hold; SAEs included fatal hemorrhage

## Summary
- FDA placed partial clinical hold on all GB5121 trials after atrial fibrillation, sudden death, and fatal intracranial hemorrhage in STAR-CNS study.
- Company terminated all ongoing GB5121 studies and discontinued development of the drug.
- Enrollment had been paused March 17, 2023, based on benefit/risk and to prioritize seralutinib program.
- No other pipeline updates disclosed; seralutinib remains the priority program.

## SEC filing metadata
- accession: 0001728117-23-000030
- form_type: 8-K
- ticker: GOSS
- cik: 0001728117
- company_name: Gossamer Bio, Inc.
- filed_at: 2023-04-03T23:59:59+00:00
- event_type: regulatory
- sentiment: negative
- materiality_score: 0.9
- calibrated_materiality_score: 0.9
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1728117/000172811723000030/0001728117-23-000030-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1728117/000172811723000030/goss-20230403.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001728117-23-000030
- JSON: https://secwatch.observer/filing/0001728117-23-000030.json
- Plain text: https://secwatch.observer/filing/0001728117-23-000030.txt

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