---
schema_version: "secwatch.filing_event.v1"
accession: "0001447362-22-000058"
form_type: "8-K"
ticker: "CSTL"
cik: "0001447362"
company_name: "CASTLE BIOSCIENCES INC"
filed_at: "2022-04-07T23:59:59+00:00"
generated_at: "2026-06-26T08:45:25.031535+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.55
calibrated_materiality_score: 0.55
confidence: "high"
source: SEC EDGAR
---

# Castle Biosciences signs 126-month lease for 44,677 sq ft Pittsburgh office/lab

## Summary
- Initial term of 126 months; first 36 months 20,856 sq ft, expanding to 44,677 sq ft from month 37.
- Base rent: $3.62/sq ft/yr first six months, then $28.62–$34.84/sq ft/yr over term.
- Landlord contributes up to $2.5M for leasehold improvements; company pays excess.
- Company has option to extend lease for one additional five-year period at fair market rent subject to floor.
- Early termination option after month 90 with $2.3M fee, subject to adjustment.

## SEC filing metadata
- accession: 0001447362-22-000058
- form_type: 8-K
- ticker: CSTL
- cik: 0001447362
- company_name: CASTLE BIOSCIENCES INC
- filed_at: 2022-04-07T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.55
- calibrated_materiality_score: 0.55
- confidence: high
- sec_items: 1.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1447362/000144736222000058/0001447362-22-000058-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1447362/000144736222000058/cstl-20220401.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001447362-22-000058
- JSON: https://secwatch.observer/filing/0001447362-22-000058.json
- Plain text: https://secwatch.observer/filing/0001447362-22-000058.txt

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