Atara Biotherapeutics, Inc. SEC filings ATRA
Atara Biotherapeutics, Inc. has 1,002 filings in SEC EDGAR's recent list, going back to Jul 9, 2015. Its latest annual report, Form 10-K, was filed on Mar 16, 2026 for the period ended Dec 31, 2025. The latest quarterly report (Form 10-Q) was filed on Aug 12, 2026, covering the quarter ended Jun 30, 2026. The most recent current report (Form 8-K) was filed on Aug 12, 2026 (results of operations). The company's fiscal year ends on December 31.
| Form | Description | Filed | Period |
|---|---|---|---|
| 10-Q | Quarterly report | Aug 12, 2026 | Jun 30, 2026 |
| 8-K |
Current report
Results of operations
|
Aug 12, 2026 | Aug 12, 2026 |
| 8-K |
Current report
Officer or director change
|
Jun 26, 2026 | Jun 22, 2026 |
| S-8 | Employee stock plan registration | Jun 12, 2026 | — |
| 8-K |
Current report
Officer or director change, Shareholder vote results
|
Jun 12, 2026 | Jun 9, 2026 |
| 424B5 | Prospectus supplement | May 12, 2026 | — |
| 10-Q | Quarterly report | May 12, 2026 | Mar 31, 2026 |
| 8-K | Current report | May 12, 2026 | May 12, 2026 |
| 8-K |
Current report
Other events
|
May 7, 2026 | May 7, 2026 |
| 8-K |
Current report
Listing notice
|
May 1, 2026 | Apr 30, 2026 |
| DEF 14A | Proxy statement | Apr 24, 2026 | Apr 24, 2026 |
| DEFA14A | Additional proxy material | Apr 24, 2026 | — |
| EFFECT | Filing | Mar 25, 2026 | — |
| 424B3 | Prospectus | Mar 25, 2026 | — |
| CORRESP | Letter to the SEC | Mar 23, 2026 | — |
| UPLOAD | Letter from the SEC | Mar 20, 2026 | — |
| S-3 | Shelf registration | Mar 17, 2026 | — |
| 424B5 | Prospectus supplement | Mar 16, 2026 | — |
| 10-K | Annual report | Mar 16, 2026 | Dec 31, 2025 |
| 8-K |
Current report
Results of operations
|
Mar 16, 2026 | Mar 16, 2026 |
| 8-K |
Current report
Other events
|
Mar 12, 2026 | Mar 12, 2026 |
| 8-K |
Current report
Other events
|
Mar 3, 2026 | Mar 3, 2026 |
| 8-K |
Current report
Material agreement, Unregistered share sale, Other events
|
Feb 23, 2026 | Feb 20, 2026 |
| 8-K |
Current report
Results of operations, Other events
|
Jan 12, 2026 | Jan 12, 2026 |
| 8-K |
Current report
Material agreement
|
Jan 2, 2026 | Dec 30, 2025 |
| 10-Q | Quarterly report | Nov 12, 2025 | Sep 30, 2025 |
| 8-K |
Current report
Results of operations
|
Nov 12, 2025 | Nov 12, 2025 |
| 8-K |
Current report
Exit or restructuring costs
|
Oct 7, 2025 | Oct 6, 2025 |
| 8-K |
Current report
Officer or director change
|
Sep 4, 2025 | Sep 2, 2025 |
| 10-Q | Quarterly report | Aug 11, 2025 | Jun 30, 2025 |
| 8-K |
Current report
Results of operations
|
Aug 11, 2025 | Aug 11, 2025 |
| 8-K |
Current report
Results of operations, Other events
|
Jul 14, 2025 | Jul 14, 2025 |
| 8-K |
Current report
Shareholder vote results
|
Jun 11, 2025 | Jun 10, 2025 |
| 8-K |
Current report
Other events
|
May 16, 2025 | May 14, 2025 |
| 424B5 | Prospectus supplement | May 15, 2025 | — |
| 10-Q | Quarterly report | May 15, 2025 | Mar 31, 2025 |
| 8-K |
Current report
Results of operations, Officer or director change
|
May 15, 2025 | May 14, 2025 |
| 8-K |
Current report
Exit or restructuring costs
|
May 12, 2025 | May 12, 2025 |
| 8-K |
Current report
Other events
|
May 6, 2025 | May 5, 2025 |
| DEFA14A | Additional proxy material | Apr 28, 2025 | — |
| DEF 14A | Proxy statement | Apr 28, 2025 | Jun 10, 2025 |
| 8-K |
Current report
Material agreement
|
Apr 4, 2025 | Mar 31, 2025 |
| 8-K |
Current report
Officer or director change
|
Mar 31, 2025 | Mar 25, 2025 |
| 10-K | Annual report | Mar 7, 2025 | Dec 31, 2024 |
| 8-K |
Current report
Results of operations
|
Mar 7, 2025 | Mar 7, 2025 |
| 8-K |
Current report
Exit or restructuring costs
|
Mar 3, 2025 | Mar 3, 2025 |
| 8-K |
Current report
Exit or restructuring costs
|
Jan 27, 2025 | Jan 27, 2025 |
| 8-K |
Current report
Other events
|
Jan 21, 2025 | Jan 21, 2025 |
| S-8 | Employee stock plan registration | Jan 17, 2025 | — |
| 8-K |
Current report
Results of operations, Other events
|
Jan 16, 2025 | Jan 16, 2025 |
| 8-K |
Current report
Bylaw or fiscal year change
|
Dec 23, 2024 | Dec 20, 2024 |
| 10-Q | Quarterly report | Nov 12, 2024 | Sep 30, 2024 |
| 8-K |
Current report
Results of operations, Officer or director change
|
Nov 12, 2024 | Nov 8, 2024 |
| 8-K |
Current report
Officer or director change
|
Oct 15, 2024 | Oct 14, 2024 |
| 424B5 | Prospectus supplement | Sep 4, 2024 | — |
| 8-K |
Current report
Officer or director change, Other events
|
Sep 3, 2024 | Sep 3, 2024 |
| 10-Q | Quarterly report | Aug 12, 2024 | Jun 30, 2024 |
| 8-K |
Current report
Results of operations, Officer or director change
|
Aug 12, 2024 | Aug 10, 2024 |
| 8-K |
Current report
Other events
|
Jul 17, 2024 | Jul 17, 2024 |
| 8-K |
Current report
Change to shareholder rights, Bylaw or fiscal year change
|
Jun 20, 2024 | Jun 20, 2024 |
| 8-K |
Current report
Other events
|
Jun 17, 2024 | Jun 17, 2024 |
| S-8 | Employee stock plan registration | Jun 11, 2024 | — |
| S-8 | Employee stock plan registration | Jun 11, 2024 | — |
| 8-K |
Current report
Shareholder vote results
|
Jun 11, 2024 | Jun 10, 2024 |
| DEFR14A | Filing | May 10, 2024 | — |
| 10-Q | Quarterly report | May 9, 2024 | Mar 31, 2024 |
| 8-K |
Current report
Results of operations
|
May 9, 2024 | May 9, 2024 |
| DEFA14A | Additional proxy material | Apr 26, 2024 | — |
| DEF 14A | Proxy statement | Apr 26, 2024 | Jun 10, 2024 |
| PRE 14A | Preliminary proxy statement | Apr 12, 2024 | Jun 10, 2024 |
| 8-K |
Current report
Officer or director change
|
Mar 29, 2024 | Mar 26, 2024 |
| 10-K | Annual report | Mar 28, 2024 | Dec 31, 2023 |
| 8-K |
Current report
Results of operations
|
Mar 28, 2024 | Mar 28, 2024 |
| 8-K |
Current report
Officer or director change
|
Feb 23, 2024 | Feb 22, 2024 |
| 424B5 | Prospectus supplement | Jan 9, 2024 | — |
| 8-K |
Current report
Material agreement, Listing notice
|
Jan 9, 2024 | Jan 8, 2024 |
| 8-K |
Current report
Exit or restructuring costs, Officer or director change, Regulation FD disclosure, Other events
|
Jan 8, 2024 | Jan 8, 2024 |
| S-8 | Employee stock plan registration | Jan 3, 2024 | — |
| 8-K |
Current report
Other events
|
Dec 20, 2023 | Dec 20, 2023 |
| 424B3 | Prospectus | Nov 17, 2023 | — |
| EFFECT | Filing | Nov 13, 2023 | — |
| 8-K |
Current report
Other events
|
Nov 9, 2023 | Nov 8, 2023 |
| CORRESP | Letter to the SEC | Nov 8, 2023 | — |
| UPLOAD | Letter from the SEC | Nov 6, 2023 | — |
| S-3 | Shelf registration | Nov 1, 2023 | — |
| 8-K |
Current report
Other events
|
Nov 1, 2023 | Nov 1, 2023 |
| 10-Q | Quarterly report | Nov 1, 2023 | Sep 30, 2023 |
| 8-K |
Current report
Material agreement, Results of operations, Exit or restructuring costs
|
Nov 1, 2023 | Oct 31, 2023 |
| 8-K |
Current report
Other events
|
Sep 20, 2023 | Sep 19, 2023 |
| 10-Q | Quarterly report | Aug 8, 2023 | Jun 30, 2023 |
| 8-K |
Current report
Results of operations
|
Aug 8, 2023 | Aug 8, 2023 |
| 8-K |
Current report
Officer or director change
|
Jun 9, 2023 | Jun 9, 2023 |
| 8-K |
Current report
Officer or director change, Shareholder vote results
|
Jun 5, 2023 | May 31, 2023 |
| 8-K |
Current report
Officer or director change
|
May 12, 2023 | May 12, 2023 |
| 10-Q | Quarterly report | May 8, 2023 | Mar 31, 2023 |
| 8-K |
Current report
Results of operations, Officer or director change
|
May 8, 2023 | May 5, 2023 |
| UPLOAD | Letter from the SEC | May 2, 2023 | — |
| CORRESP | Letter to the SEC | Apr 21, 2023 | — |
| DEFA14A | Additional proxy material | Apr 7, 2023 | — |
| DEF 14A | Proxy statement | Apr 7, 2023 | — |
| 8-K |
Current report
Officer or director change
|
Mar 31, 2023 | Mar 31, 2023 |
| UPLOAD | Letter from the SEC | Mar 27, 2023 | — |
| PRE 14A | Preliminary proxy statement | Mar 24, 2023 | — |
| 8-K |
Current report
Regulation FD disclosure
|
Mar 10, 2023 | Mar 10, 2023 |
| EFFECT | Filing | Feb 13, 2023 | — |
| POS AM | Filing | Feb 9, 2023 | — |
| S-8 | Employee stock plan registration | Feb 9, 2023 | — |
| 10-K | Annual report | Feb 8, 2023 | Dec 31, 2022 |
| POSASR | Filing | Feb 8, 2023 | — |
| 8-K |
Current report
Results of operations, Officer or director change
|
Feb 8, 2023 | Feb 3, 2023 |
| 8-K |
Current report
New debt
|
Jan 6, 2023 | Dec 30, 2022 |
| 8-K |
Current report
Material agreement
|
Dec 20, 2022 | Dec 20, 2022 |
| 8-K |
Current report
Officer or director change, Other events
|
Dec 19, 2022 | Dec 16, 2022 |
| 10-Q | Quarterly report | Nov 8, 2022 | Sep 30, 2022 |
| 8-K |
Current report
Results of operations
|
Nov 8, 2022 | Nov 8, 2022 |
| 8-K |
Current report
Material agreement
|
Sep 28, 2022 | Sep 28, 2022 |
| 8-K |
Current report
Bylaw or fiscal year change
|
Sep 27, 2022 | Sep 26, 2022 |
| 10-Q | Quarterly report | Aug 8, 2022 | Jun 30, 2022 |
| 8-K |
Current report
Material agreement, Results of operations, Exit or restructuring costs, Officer or director change
|
Aug 8, 2022 | Aug 2, 2022 |
| S-8 | Employee stock plan registration | Jul 22, 2022 | — |
| 8-K |
Current report
Shareholder vote results
|
Jun 24, 2022 | Jun 23, 2022 |
| 8-K |
Current report
Agreement ended
|
May 19, 2022 | May 13, 2022 |
| 10-Q | Quarterly report | May 5, 2022 | Mar 31, 2022 |
| 8-K |
Current report
Results of operations
|
May 5, 2022 | May 5, 2022 |
| DEFA14A | Additional proxy material | Apr 27, 2022 | — |
| DEF 14A | Proxy statement | Apr 27, 2022 | Jun 23, 2022 |
| 8-K |
Current report
Acquisition or sale of assets
|
Apr 4, 2022 | Apr 4, 2022 |
| S-8 | Employee stock plan registration | Feb 28, 2022 | — |
| 10-K | Annual report | Feb 28, 2022 | Dec 31, 2021 |
| 8-K |
Current report
Results of operations
|
Feb 28, 2022 | Feb 28, 2022 |
| 8-K |
Current report
Other events
|
Feb 18, 2022 | Feb 18, 2022 |
| 8-K |
Current report
Material agreement, Results of operations, Officer or director change
|
Jan 26, 2022 | Jan 26, 2022 |
| 8-K |
Current report
Regulation FD disclosure
|
Jan 10, 2022 | Jan 10, 2022 |
| 8-K |
Current report
Other events
|
Nov 26, 2021 | Nov 26, 2021 |
| 424B5 | Prospectus supplement | Nov 26, 2021 | — |
| 10-Q | Quarterly report | Nov 4, 2021 | Sep 30, 2021 |
| 8-K |
Current report
Results of operations
|
Nov 4, 2021 | Nov 4, 2021 |
| 8-K |
Current report
Material agreement
|
Oct 4, 2021 | Oct 2, 2021 |
| S-8 | Employee stock plan registration | Sep 29, 2021 | — |
| 8-K |
Current report
Officer or director change
|
Aug 10, 2021 | Aug 9, 2021 |
| 10-Q | Quarterly report | Aug 9, 2021 | Jun 30, 2021 |
| 8-K |
Current report
Results of operations
|
Aug 9, 2021 | Aug 9, 2021 |
| 8-K |
Current report
Shareholder vote results
|
Jun 9, 2021 | Jun 8, 2021 |
| DEFA14A | Additional proxy material | May 28, 2021 | — |
| 10-Q | Quarterly report | May 4, 2021 | Mar 31, 2021 |
| 8-K |
Current report
Results of operations
|
May 4, 2021 | May 4, 2021 |
| DEFA14A | Additional proxy material | Apr 22, 2021 | — |
| DEF 14A | Proxy statement | Apr 22, 2021 | Jun 8, 2021 |
| S-8 | Employee stock plan registration | Mar 1, 2021 | — |
| S-3ASR | Automatic shelf registration | Mar 1, 2021 | — |
| 10-K | Annual report | Mar 1, 2021 | Dec 31, 2020 |
| 8-K |
Current report
Results of operations
|
Mar 1, 2021 | Mar 1, 2021 |
| 8-K |
Current report
Regulation FD disclosure
|
Jan 11, 2021 | Jan 11, 2021 |
| 8-K |
Current report
Other events
|
Jan 4, 2021 | Jan 4, 2021 |
| 8-K |
Current report
Other events
|
Dec 9, 2020 | Dec 8, 2020 |
| 424B5 | Prospectus supplement | Dec 9, 2020 | — |
| 424B5 | Prospectus supplement | Dec 7, 2020 | — |
| 8-K |
Current report
Material agreement
|
Dec 7, 2020 | Dec 4, 2020 |
| S-8 | Employee stock plan registration | Nov 9, 2020 | — |
| 10-Q | Quarterly report | Nov 9, 2020 | Sep 30, 2020 |
| 8-K |
Current report
Results of operations
|
Nov 9, 2020 | Nov 9, 2020 |
| 10-Q | Quarterly report | Aug 5, 2020 | Jun 30, 2020 |
| 8-K |
Current report
Results of operations
|
Aug 5, 2020 | Aug 5, 2020 |
| 8-K |
Current report
Shareholder vote results
|
Jun 19, 2020 | Jun 16, 2020 |
| DEFA14A | Additional proxy material | Jun 5, 2020 | — |
| 8-K |
Current report
Other events
|
May 28, 2020 | May 26, 2020 |
| 424B5 | Prospectus supplement | May 27, 2020 | — |
| 424B5 | Prospectus supplement | May 26, 2020 | — |
| 8-K |
Current report
Officer or director change
|
May 12, 2020 | May 8, 2020 |
| 10-Q | Quarterly report | May 6, 2020 | Mar 31, 2020 |
| 8-K |
Current report
Results of operations
|
May 6, 2020 | May 6, 2020 |
| 8-K |
Current report
Officer or director change
|
Apr 30, 2020 | Apr 29, 2020 |
| DEFA14A | Additional proxy material | Apr 22, 2020 | — |
| DEF 14A | Proxy statement | Apr 22, 2020 | Jun 16, 2020 |
| S-8 | Employee stock plan registration | Feb 27, 2020 | — |
| 424B5 | Prospectus supplement | Feb 27, 2020 | — |
| 10-K | Annual report | Feb 27, 2020 | Dec 31, 2019 |
| 8-K |
Current report
Results of operations
|
Feb 27, 2020 | Feb 27, 2020 |
| 10-Q | Quarterly report | Nov 7, 2019 | Sep 30, 2019 |
| 8-K |
Current report
Results of operations
|
Nov 7, 2019 | Nov 7, 2019 |
| 8-K |
Current report
Officer or director change
|
Oct 25, 2019 | Oct 21, 2019 |
| 10-Q | Quarterly report | Aug 8, 2019 | Jun 30, 2019 |
| 8-K |
Current report
Results of operations
|
Aug 8, 2019 | Aug 8, 2019 |
| 8-K |
Current report
Results of operations, Other events
|
Jul 22, 2019 | Jul 18, 2019 |
| 424B5 | Prospectus supplement | Jul 19, 2019 | — |
| 424B5 | Prospectus supplement | Jul 18, 2019 | — |
| 8-K |
Current report
Shareholder vote results
|
Jun 28, 2019 | Jun 27, 2019 |
| 8-K |
Current report
Other events
|
Jun 5, 2019 | Jun 5, 2019 |
| 8-K |
Current report
Officer or director change
|
May 28, 2019 | May 23, 2019 |
| 10-Q | Quarterly report | May 9, 2019 | Mar 31, 2019 |
| 8-K |
Current report
Results of operations
|
May 9, 2019 | May 9, 2019 |
| DEFA14A | Additional proxy material | Apr 30, 2019 | — |
| DEF 14A | Proxy statement | Apr 30, 2019 | Jun 27, 2019 |
| 8-K |
Current report
Officer or director change
|
Apr 3, 2019 | Mar 29, 2019 |
| CT ORDER | Filing | Mar 11, 2019 | — |
| S-8 | Employee stock plan registration | Feb 26, 2019 | — |
| 424B5 | Prospectus supplement | Feb 26, 2019 | — |
| 10-K | Annual report | Feb 26, 2019 | Dec 31, 2018 |
| 8-K |
Current report
Results of operations
|
Feb 26, 2019 | Feb 26, 2019 |
| 8-K |
Current report
Officer or director change
|
Jan 3, 2019 | Jan 2, 2019 |
Showing 200 filings, the most recent 200. Main filings leave out insider and ownership forms such as Form 4; choose a type above to see them. Each form opens on SEC.gov. Older filings are on SEC EDGAR.
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Company profile
- Industry
- Biological Products, (No Diagnostic Substances) (SIC 2836)
- Listed as
- ATRA (Nasdaq)
- Fiscal year ends
- December 31
- Incorporated in
- DE
- Headquarters
- Thousand Oaks, CA
- SEC filer status
- Non-accelerated filer, Smaller reporting company
- SEC CIK
- 1604464
Other Biological Products, (No Diagnostic Substances) companies
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All 182 Biological Products, (No Diagnostic Substances) companies
Source: SEC EDGAR filings. This is company-reported data, not investment advice.