---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-25-046948"
form_type: "8-K"
ticker: "KYNB"
cik: "0000921299"
company_name: "KYNTRA BIO, INC."
filed_at: "2025-03-28T23:59:59+00:00"
generated_at: "2026-05-24T03:31:53.131919+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.3
calibrated_materiality_score: 0.3
confidence: "high"
source: SEC EDGAR
---

# FibroGen and Fortis amend agreements, extend option exercise deadline to Dec 31, 2027

## Summary
- Amendments No.1 to Evaluation Agreement and Option Agreement & Plan of Merger executed March 28, 2025.
- Original agreements dated June 6, 2024, as amended and restated from May 5, 2023.
- Option exercise deadline under both agreements extended to December 31, 2027.
- Full text of amendments to be filed with FibroGen's Q1 2025 10-Q.

## SEC filing metadata
- accession: 0000950170-25-046948
- form_type: 8-K
- ticker: KYNB
- cik: 0000921299
- company_name: KYNTRA BIO, INC.
- filed_at: 2025-03-28T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.3
- calibrated_materiality_score: 0.3
- confidence: high
- sec_items: 1.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/921299/000095017025046948/0000950170-25-046948-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/921299/000095017025046948/fgen-20250328.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-25-046948
- JSON: https://secwatch.observer/filing/0000950170-25-046948.json
- Plain text: https://secwatch.observer/filing/0000950170-25-046948.txt

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