---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-24-037643"
form_type: "8-K"
ticker: "ATRA"
cik: "0001604464"
company_name: "Atara Biotherapeutics, Inc."
filed_at: "2024-03-28T23:59:59+00:00"
generated_at: "2026-06-04T06:10:39.069220+00:00"
event_type: "earnings"
sentiment: "negative"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# Atara posts Q4 loss $0.56/sh; tab-cel BLA submission on track for Q2 2024

## Summary
- Q4 net loss $60.5M ($0.56/diluted share); FY 2023 net loss $276.1M ($2.61/diluted share).
- Cash, cash equivalents and short-term investments $51.7M at Dec 31, 2023; pro-forma ~$104M after Q1 2024 proceeds.
- Tab-cel BLA submission on track for Q2 2024; $20M regulatory milestone expected in April 2024.
- ATA3219 lupus nephritis Phase 1 to start H2 2024, initial data H1 2025; NHL study enrolling with data Q4 2024.
- Two workforce reductions: ~30% in Nov 2023 and further ~25% in Jan 2024; headcount now ~170.

## SEC filing metadata
- accession: 0000950170-24-037643
- form_type: 8-K
- ticker: ATRA
- cik: 0001604464
- company_name: Atara Biotherapeutics, Inc.
- filed_at: 2024-03-28T23:59:59+00:00
- event_type: earnings
- sentiment: negative
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 2.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1604464/000095017024037643/0000950170-24-037643-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1604464/000095017024037643/atra-20240328.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-24-037643
- JSON: https://secwatch.observer/filing/0000950170-24-037643.json
- Plain text: https://secwatch.observer/filing/0000950170-24-037643.txt

## Key facts
- Earnings Releases
  Atara Biotherapeutics, Inc. reported the fourth quarter and full year 2023 results: net income net losses of $60.5 million, or $0.56 per share, and $276.1 million, or $2.61 per share, for the fourth quarter and fisc, EPS $0.56 per share for the fourth quarter and $2.61 per share for the fiscal year 2023.
  - Period: the fourth quarter and full year 2023
  - Net income: net losses of $60.5 million, or $0.56 per share, and $276.1 million, or $2.61 per share, for the fourth quarter and fisc
  - EPS: $0.56 per share for the fourth quarter and $2.61 per share for the fiscal year 2023
  - Result: reported results
  source text: Fourth Quarter and Full Year 2023 Financial Results • Cash, cash equivalents and short-term investments as of December 31, 2023 totaled $51.7 million, as compared to $102.4 million as of September 30, 2023 and $242.8 million as of December 31, 2022 • Net cash used in operating activities was $50.4 million and $193.0 million for the fourth quarter and fiscal year 2023, as compared to $56.9 million and $270.4 million in the same periods in 2022 • Atara reported net losses of $60.5 million, or $0.56 per share, and $276.1 million, or $2.61 per share, for the fourth quarter and fiscal year 2023, respectively, as compared to $74.6 million, or $0.72 per share, and $228.3 million, or $2.24 per share, for the same periods in 2022
  evidence_url: https://www.sec.gov/Archives/edgar/data/1604464/000095017024037643/0000950170-24-037643-index.htm

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