---
schema_version: "secwatch.filing_event.v1"
accession: "0001140361-22-012901"
form_type: "8-K"
ticker: "CSTL"
cik: "0001447362"
company_name: "CASTLE BIOSCIENCES INC"
filed_at: "2022-04-04T23:59:59+00:00"
generated_at: "2026-06-26T09:45:44.387510+00:00"
event_type: "m_and_a"
sentiment: "neutral"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Castle Biosciences to acquire AltheaDx for $65M upfront plus up to $75M in milestones

## Summary
- Upfront consideration: $32.5M cash + $32.5M stock; milestone payments up to $75M tied to 2022-2024 revenue and Medicare coverage.
- AltheaDx had <$1M revenue in 2021; its IDgenetix test focuses on mental health pharmacogenomics.
- Expected Q2 2022 close; subject to AltheaDx stockholder approval and other customary conditions.
- CEO Derek Maetzold and Chairman Daniel Bradbury are AltheaDx directors and beneficial owners, creating related-party transactions.

## SEC filing metadata
- accession: 0001140361-22-012901
- form_type: 8-K
- ticker: CSTL
- cik: 0001447362
- company_name: CASTLE BIOSCIENCES INC
- filed_at: 2022-04-04T23:59:59+00:00
- event_type: m_and_a
- sentiment: neutral
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 1.01, 3.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1447362/000114036122012901/0001140361-22-012901-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1447362/000114036122012901/ny20003735x1_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001140361-22-012901
- JSON: https://secwatch.observer/filing/0001140361-22-012901.json
- Plain text: https://secwatch.observer/filing/0001140361-22-012901.txt

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