---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-21-290938"
form_type: "8-K"
ticker: "ANNX"
cik: "0001528115"
company_name: "Annexon, Inc."
filed_at: "2021-10-04T23:59:59+00:00"
generated_at: "2026-06-28T23:24:20.575366+00:00"
event_type: "leadership"
sentiment: "positive"
materiality_score: 0.55
calibrated_materiality_score: 0.55
confidence: "high"
source: SEC EDGAR
---

# Annexon promotes Yednock to CIO, hires Mattheakis as CSO

## Summary
- Ted Yednock, formerly CSO since 2013, promoted to Chief Innovation Officer effective immediately.
- Larry Mattheakis appointed Chief Scientific Officer; previously SVP at Protagonist Therapeutics.
- Yednock remains on executive committee, chairs Scientific Advisory Board; focus on C1q platform expansion.
- Mattheakis brings drug discovery experience; company has three clinical-stage candidates in seven trials.

## SEC filing metadata
- accession: 0001193125-21-290938
- form_type: 8-K
- ticker: ANNX
- cik: 0001528115
- company_name: Annexon, Inc.
- filed_at: 2021-10-04T23:59:59+00:00
- event_type: leadership
- sentiment: positive
- materiality_score: 0.55
- calibrated_materiality_score: 0.55
- confidence: high
- sec_items: 5.02, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1528115/000119312521290938/0001193125-21-290938-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1528115/000119312521290938/d225159d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-21-290938
- JSON: https://secwatch.observer/filing/0001193125-21-290938.json
- Plain text: https://secwatch.observer/filing/0001193125-21-290938.txt

## Key facts
- Executive change
  Ted Yednock was appointed as Chief Innovation Officer at Annexon, Inc..
  - Action: appointed
  - Role: Chief Innovation Officer
  source text: appointed Ted Yednock, Ph.D. as Chief Innovation Officer
  evidence_url: https://www.sec.gov/Archives/edgar/data/1528115/000119312521290938/0001193125-21-290938-index.htm
- Executive change
  Larry Mattheakis was appointed as Chief Scientific Officer at Annexon, Inc..
  - Action: appointed
  - Role: Chief Scientific Officer
  source text: Larry Mattheakis, Ph.D. as Chief Scientific Officer
  evidence_url: https://www.sec.gov/Archives/edgar/data/1528115/000119312521290938/0001193125-21-290938-index.htm

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