---
schema_version: "secwatch.filing_event.v1"
accession: "0001711279-22-000055"
form_type: "8-K"
ticker: "KRYS"
cik: "0001711279"
company_name: "Krystal Biotech, Inc."
filed_at: "2022-11-03T23:59:59+00:00"
generated_at: "2026-06-22T09:30:06.929594+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# KB407 CF gene therapy data: human CFTR expression 106–440% of endogenous in NHPs; IND accepted

## Summary
- KB407 transduced ciliated, club, and goblet cells in NHP airways; no transduction of basal cells.
- Human CFTR transcript levels reached 106–440% of endogenous NHP CFTR in lung biopsies.
- No adverse findings in GLP toxicology study; NOAEL at highest dose tested.
- FDA accepted KB407 IND in July 2022.
- No significant cytokine induction in human CF cells after KB407 transduction.

## SEC filing metadata
- accession: 0001711279-22-000055
- form_type: 8-K
- ticker: KRYS
- cik: 0001711279
- company_name: Krystal Biotech, Inc.
- filed_at: 2022-11-03T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1711279/000171127922000055/0001711279-22-000055-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1711279/000171127922000055/krys-20221103.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001711279-22-000055
- JSON: https://secwatch.observer/filing/0001711279-22-000055.json
- Plain text: https://secwatch.observer/filing/0001711279-22-000055.txt

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