---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-068789"
form_type: "8-K"
ticker: "ATRA"
cik: "0001604464"
company_name: "Atara Biotherapeutics, Inc."
filed_at: "2025-03-31T23:59:59+00:00"
generated_at: "2026-05-24T01:52:00.966205+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Atara CFO/COO Eric Hyllengren to depart March 31; Yanina Grant-Huerta named CAO

## Summary
- CFO/COO Eric Hyllengren's employment ends March 31, 2025; he will provide consulting through July 31 at an hourly rate.
- Hyllengren receives severance including 2024 bonus; he relinquishes all vested and unvested stock option awards.
- Yanina Grant-Huerta appointed Chief Accounting Officer and principal accounting officer effective March 31; she was VP of FP&A since March 2023.
- Grant-Huerta previously spent 13 years at Amgen; no family relationships or related-party transactions disclosed.

## SEC filing metadata
- accession: 0001193125-25-068789
- form_type: 8-K
- ticker: ATRA
- cik: 0001604464
- company_name: Atara Biotherapeutics, Inc.
- filed_at: 2025-03-31T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 5.02
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1604464/000119312525068789/0001193125-25-068789-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1604464/000119312525068789/d905889d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-068789
- JSON: https://secwatch.observer/filing/0001193125-25-068789.json
- Plain text: https://secwatch.observer/filing/0001193125-25-068789.txt

## Key facts
- Executive change
  Eric Hyllengren departed as Chief Financial Officer and Chief Operating Officer at Atara Biotherapeutics, Inc..
  - Action: ended
  - Role: Chief Financial Officer and Chief Operating Officer
  source text: On March 25, 2025, it was agreed that the employment of Eric Hyllengren, the Chief Financial Officer and Chief Operating Officer of Atara Biotherapeutics, Inc. (the “ Company ”), would end effective March 31, 2025.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1604464/000119312525068789/0001193125-25-068789-index.htm
- Executive change
  Yanina Grant-Huerta was appointed as Chief Accounting Officer at Atara Biotherapeutics, Inc..
  - Action: appointed
  - Role: Chief Accounting Officer
  source text: On March 31, 2025, the Company appointed Yanina Grant-Huerta as the Company’s Chief Accounting Officer and principal accounting officer, effective March 31, 2025.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1604464/000119312525068789/0001193125-25-068789-index.htm

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