---
schema_version: "secwatch.filing_event.v1"
accession: "0001728117-24-000052"
form_type: "8-K"
ticker: "GOSS"
cik: "0001728117"
company_name: "Gossamer Bio, Inc."
filed_at: "2024-05-06T23:59:59+00:00"
generated_at: "2026-06-02T22:13:54.678532+00:00"
event_type: "m_and_a"
sentiment: "positive"
materiality_score: 0.9
calibrated_materiality_score: 0.9
confidence: "high"
source: SEC EDGAR
---

# Gossamer Bio enters global collaboration with Chiesi for seralutinib; receives $160M upfront

## Summary
- Receives $160M development reimbursement; eligible for up to $146M regulatory and $180M sales milestones.
- Gossamer leads US commercialization for PAH/PH-ILD with 50/50 profit split; Chiesi obtains ex-US rights with tiered royalties.
- Companies plan to initiate Phase 3 registrational study of seralutinib in PH-ILD in mid-2025.
- Existing MidCap credit facility terminated and repaid in full upon deal closing.
- Chiesi receives equity option to purchase up to 9.9% of Gossamer at 107.5% of VWAP, min $1.63/share.

## SEC filing metadata
- accession: 0001728117-24-000052
- form_type: 8-K
- ticker: GOSS
- cik: 0001728117
- company_name: Gossamer Bio, Inc.
- filed_at: 2024-05-06T23:59:59+00:00
- event_type: m_and_a
- sentiment: positive
- materiality_score: 0.9
- calibrated_materiality_score: 0.9
- confidence: high
- sec_items: 1.01, 1.02, 3.02, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1728117/000172811724000052/0001728117-24-000052-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1728117/000172811724000052/goss-20240503.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001728117-24-000052
- JSON: https://secwatch.observer/filing/0001728117-24-000052.json
- Plain text: https://secwatch.observer/filing/0001728117-24-000052.txt

## Key facts
- Material Agreements
  Gossamer Bio, Inc. entered into Chiesi Collaboration Agreement with Chiesi Farmaceutici S.p.A and Chiesi USA, Inc. (collectively, Chiesi) valued at Upfront payment of $160 million, plus up to $146 million in regulatory milestones and $180 million i (effective 2024-05-03).
  - Action: entry
  - Agreement: collaboration
  - Counterparty: Chiesi Farmaceutici S.p.A and Chiesi USA, Inc. (collectively, Chiesi)
  - Value: Upfront payment of $160 million, plus up to $146 million in regulatory milestones and $180 million i
  - Effective: 2024-05-03
  source text: On May 3, 2024, Gossamer Bio, Inc. (“Gossamer” or the “Company”), GB002, Inc., a Delaware corporation and wholly-owned subsidiary of the Company (“GB002”), and Gossamer Bio 002 Ltd., a corporation organized and existing under the laws of Ireland and indirect wholly-owned subsidiary of the Company, entered into a global collaboration and license agreement (the “Chiesi Collaboration Agreement”) with Chiesi Farmaceutici S.p.A and Chiesi USA, Inc. (collectively, “Chiesi”). The collaboration is focused on the development and commercialization of seralutinib and licensed products including seralutinib and related licensed compounds (“Licensed Products”) in the US (“US Territory”) and the rest of the world (“ROW Territory”), for therapeutic, prophylactic and diagnostic uses in humans and animals, for the treatment of pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with interstitial lung disease (PH-ILD) and other indications, as may be permitted under the Chiesi Co
  evidence_url: https://www.sec.gov/Archives/edgar/data/1728117/000172811724000052/0001728117-24-000052-index.htm

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