---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-062534"
form_type: "8-K"
ticker: "ATRA"
cik: "0001604464"
company_name: "Atara Biotherapeutics, Inc."
filed_at: "2026-02-23T23:59:59+00:00"
generated_at: "2026-05-16T01:09:54.076848+00:00"
event_type: "other"
sentiment: "neutral"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Atara defers $9M milestone payment to HCRx to Jan 2028; issues 400K share warrant

## Summary
- HCRx agreed to extend $9.0M milestone payment due from June 30, 2026 to Jan 1, 2028.
- Atara issued warrant to purchase 400K shares at $0.0001/share, exercisable immediately, no expiration.
- CEO cites flexibility to address FDA Complete Response Letter (CRL) for tabelecleucel.
- Tabelecleucel is approved in Europe for EBV+ PTLD; working with FDA for US path.
- Warrant subject to 4.99% beneficial ownership limit; net number via cashless exercise.

## SEC filing metadata
- accession: 0001193125-26-062534
- form_type: 8-K
- ticker: ATRA
- cik: 0001604464
- company_name: Atara Biotherapeutics, Inc.
- filed_at: 2026-02-23T23:59:59+00:00
- event_type: other
- sentiment: neutral
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 1.01, 3.02, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1604464/000119312526062534/0001193125-26-062534-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1604464/000119312526062534/d105335d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-062534
- JSON: https://secwatch.observer/filing/0001193125-26-062534.json
- Plain text: https://secwatch.observer/filing/0001193125-26-062534.txt

## Key facts
- Material Agreements
  Atara Biotherapeutics, Inc. amended Amendment with HCR Molag Fund, L.P. valued at $9.0 million (effective 2026-02-20).
  - Action: amendment
  - Agreement: credit facility
  - Counterparty: HCR Molag Fund, L.P.
  - Value: $9.0 million
  - Effective: 2026-02-20
  source text: On February 20, 2026, Atara Biotherapeutics, Inc., (the “Company”) entered into an Amendment (the “Amendment”) to the Purchase and Sale Agreement dated as of December 20, 2022 (the “Agreement”) with HCR Molag Fund, L.P. (“HCR”). Under the terms of the Amendment, HCR agreed to amend the due date of the one-time of $9.0 million cash payment
  evidence_url: https://www.sec.gov/Archives/edgar/data/1604464/000119312526062534/0001193125-26-062534-index.htm

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