---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-058978"
form_type: "8-K"
ticker: "ACLX"
cik: "0001786205"
company_name: "Arcellx, Inc."
filed_at: "2025-03-20T23:59:59+00:00"
generated_at: "2026-05-24T10:30:26.235260+00:00"
event_type: "leadership"
sentiment: "positive"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "high"
source: SEC EDGAR
---

# Arcellx appoints Andrew Galligan and Kristin Myers to board; Derek Yoon resigns

## Summary
- Derek Yoon resigned from the board effective March 18, 2025; no disagreements.
- Board size expanded from 7 to 8; Galligan and Myers appointed as Class I and III directors.
- Galligan brings financial leadership (ex-CFO of Nevro, Ooma); Myers adds payer/provider expertise (COO of Blue Cross Blue Shield Assn.).
- New directors receive $50k annual retainer, $850k initial option grant (3-yr vest), and $425k annual option grant.
- Company highlights anito-cel progress and expects commercial launch in 2026.

## SEC filing metadata
- accession: 0001193125-25-058978
- form_type: 8-K
- ticker: ACLX
- cik: 0001786205
- company_name: Arcellx, Inc.
- filed_at: 2025-03-20T23:59:59+00:00
- event_type: leadership
- sentiment: positive
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: high
- sec_items: 5.02, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1786205/000119312525058978/0001193125-25-058978-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1786205/000119312525058978/d905953d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-058978
- JSON: https://secwatch.observer/filing/0001193125-25-058978.json
- Plain text: https://secwatch.observer/filing/0001193125-25-058978.txt

## Key facts
- Executive change
  Andrew Galligan was appointed as Director at Arcellx, Inc..
  - Action: appointed
  - Role: Director
  source text: On March 18, 2025, the Board appointed Andrew Galligan to fill one of the two vacancies on the Board, effective March 18, 2025, as a Class I director
  evidence_url: https://www.sec.gov/Archives/edgar/data/1786205/000119312525058978/0001193125-25-058978-index.htm
- Executive change
  Kristin Myers was appointed as Director at Arcellx, Inc..
  - Action: appointed
  - Role: Director
  source text: On March 18, 2025, the Board appointed Kristin Myers to fill one of the two vacancies on the Board, effective March 18, 2025, as a Class III director
  evidence_url: https://www.sec.gov/Archives/edgar/data/1786205/000119312525058978/0001193125-25-058978-index.htm
- Executive change
  Derek Yoon resigned as Director at Arcellx, Inc..
  - Action: resigned
  - Role: Director
  source text: On March 17, 2025, Arcellx, Inc. (the “Company”) was notified by Derek Yoon that he intended to resign from the Company’s board of directors (the “Board”) and from the Board committees on which he served.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1786205/000119312525058978/0001193125-25-058978-index.htm

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