Management Change/Compensation (Form 8-K)

Item 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain
Officers; Compensatory Arrangements of Certain Officers.

(b)

On June 22, 2026, Atara Biotherapeutics, Inc. (the "Company") notified Yanina Grant-Huerta, the Company's Chief Accounting Officer, that her employment with the Company would end effective July 17, 2026.

(c)

On June 26, 2026, the Company's Board of Directors appointed Kevin G. Sarney, Life Science Practice Leader at Charles River CFO, Inc. ("CRCFO"), as interim chief financial officer, effective as of June 26, 2026. In connection with his appointment, Mr. Sarney will serve as the Company's principal financial officer and principal accounting officer. Mr. Sarney will provide interim chief financial officer services pursuant to a consulting agreement with CRCFO to which the Company is a party (the "Consulting Agreement"). Under the Consulting Agreement, the Company will pay CRCFO an agreed upon hourly rate for Mr. Sarney's services. Mr. Sarney will not receive any compensation directly from the Company. The Consulting Agreement may be terminated by either the Company or CRCFO upon 30 days written notice. Mr. Sarney will enter into the Company's standard indemnification agreement for directors and executive officers.

Mr. Sarney, age 61, has over 25 years of finance and accounting experience with life science companies. Since January 2021, Mr. Sarney has served as a consultant at CRCFO, a provider of strategic and operational finance and accounting services for life science companies. Prior to joining CRCFO, Mr. Sarney served in executive finance positions with a number of publicly traded and privately held life science companies. Earlier in his career, Mr. Sarney was an auditor at PricewaterhouseCoopers. Mr. Sarney received a B.S. in Management from the University of Hartford, an M.S. in Accounting from the Sawyer Business School at Suffolk University, and an M.B.A. in Finance from the Questrom School of Business at Boston University. In addition, Mr. Sarney is a licensed Certified Public Accountant in Massachusetts.

There are no arrangements or understandings between Mr. Sarney and any other person pursuant to which Mr. Sarney was appointed principal financial officer and principal accounting officer. There are no family relationships between Mr. Sarney and any director, executive officer or any other person nominated or chosen by the Company to become a director or executive officer. There are no related person transactions (within the meaning of Item 404(a) of Regulation S-K promulgated by the Securities and Exchange Commission) between Mr. Sarney and the Company.