Company: ATRA
Filing Date: 2025-01-17
Form Type: S-8
Source: 0001193125-25-008413
Chunk: 2

Company: Atara Biotherapeutics, Inc.
Filing Date: 2025-01-17
Form: S-8
Chunk 2
---
 June 20, 2024, and incorporated herein by reference. |

| (4) | Filed as Exhibit 4.1 to Amendment No. 1 to the Registrant’s Registration Statement on Form S-1 (File No. 333-196936), filed with the SEC on July 10, 2014, and incorporated herein by reference. |

| (5) | Filed as Exhibit 4.4 to the Registrant’s Registration Statement on Form                               
 S-8 (File No. 333-280125), filed with the SEC on June 11, 2024, and incorporated herein by reference. |

| * | Filed herewith. |

SIGNATURES Pursuant to the requirements of the Securities Act of 1933, as amended, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Thousand Oaks, State of California, on this 17th day of January, 2025.

| ATARA BIOTHERAPEUTICS, INC. |     |                                         |
| By:                         |     | /s/ AnhCo Nguyen                        |
|                             |     | AnhCo Nguyen, Ph.D. President and Chief 
 Executive Officer                       |

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints AnhCo Nguyen, Ph.D. and Eric Hyllengren, and each of them, as his or her true and lawful attorneys-in-factand agents, each with the full power of substitution, for him or her and in his or her name, place or stead, in any and all capacities, to sign any and all amendments to this Registration Statement (including post-effective amendments), and to sign any registration statement for the same offering covered by this Registration Statement that is to be effective upon filing pursuant to Rule 462(b) promulgated under the Securities Act of 1933, as amended, and all post-effective amendments thereto, and to file the same, with exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-factand agents, and each of them, full power and authority to do and perform each and every act and thing requisite and necessary to be done in and about the premises, as fully to all intents and purposes as he