UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

     Date of Report (Date of earliest event reported): September 02, 2025

    

Atara Biotherapeutics, Inc.

(Exact name of Registrant as Specified in Its Charter)


Delaware	001-36548	46-0920988
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(IRS Employer Identification No.)

1280 Rancho Conejo Blvd
Thousand Oaks, California		91320
(Address of Principal Executive Offices)		(Zip Code)

     Registrant’s Telephone Number, Including Area Code: (805) 623-4211

    

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:


Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock, par value $0.0001 per share	ATRA	The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

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

(b) Following an assessment by the Board of Directors (the “Board”) of Atara Biotherapeutics, Inc., a Delaware corporation (the “Company”), of its size and composition, the Board determined that a reduction in the number of directors would help right-size the Board to reflect the Company's current operations and further align the size of the Company’s Board with the boards of public companies of similar size. As a result of such determination, on September 2, 2025, each of Ameet Mallik, Pascal Touchon, and Maria Grazia Roncarolo, M.D., notified the Board that they will each voluntarily resign from the Board effective as of September 2, 2025 (the “Resignation Effective Date”). In connection with such resignations, the Board reduced its size from ten (10) to seven (7) directors, as of the Resignation Effective Date.

In connection with the resignation of Pascal Touchon, who served as Chair of the Board, the Board appointed Gregory A. Ciongoli to serve as Chair of the Board.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.


			ATARA BIOTHERAPEUTICS, INC.

Date:	September 3, 2025	By:	/s/ Yanina Grant-Huerta
			Yanina Grant-Huerta Chief Accounting Officer

Atara Biotherapeutics, Inc. 8-K