SEC Form 8-K filed by Atara Biotherapeutics Inc.

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): May 14, 2025

Atara Biotherapeutics, Inc.

(Exact name of Registrant as Specified in Its Charter)

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:

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

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. ☐

On May 14, 2024, the Company entered into an underwriting agreement (the “Underwriting Agreement”) with TD Securities (USA) LLC, as representative (the “Representative”) of the underwriters (the “Underwriters”) named therein, pursuant to which the Company agreed to issue and sell to the Underwriters in an underwritten registered direct offering (the “Offering”) an aggregate of (i) 834,237 shares (the “Shares”) of the Company’s common stock, par value $0.0001 per share (the “Common Stock”) and (ii) pre-funded warrants (each, a “Pre-Funded Warrant,” and together, the “Pre-Funded Warrants”) to purchase up to 1,587,108 shares of Common Stock, at a purchase price of $6.61 per Share and $6.6099 per share underlying the Pre-Funded Warrants. The exercise price of each Pre-Funded Warrant is equal to $0.0001 per share, subject to adjustment as provided therein, and the Pre-Funded Warrants will be exercisable immediately and have no expiration date.

The Pre-Funded Warrants may be exercised by means of cash or the holder may elect to receive upon such exercise the net number of shares of Common Stock determined according to a formula set forth in the Pre-Funded Warrants.

The aggregate gross proceeds to the Company from the Offering are expected to be approximately $16.0 million, before deducting underwriting discounts and commissions and estimated offering expenses payable by the Company. The Representative is purchasing 834,237 Shares and Pre-Funded Warrants to purchase up to 1,587,108 shares of Common Stock in the Offering at an aggregate purchase price of $16.0 million. The Company intends to use the net proceeds from the Offering to fund its ongoing activities required to achieve the biologics license application (BLA) approval for tab-cel, and for working capital and other general corporate purposes. The Offering was made pursuant to an effective shelf registration statement on Form S-3 (File No. 333-275256) that was filed with the Securities and Exchange Commission (the “SEC”) on November 1, 2023 and declared effective by the SEC on November 13, 2023 and prospectus supplement to be filed with the SEC. The Offering is expected to close on May 16, 2025 (the “Closing Date”).

Pursuant to the Underwriting Agreement, the Company has agreed to certain restrictions on the issuance and sale of shares of the Company’s securities for a period of 30 days following the Closing Date, subject to certain exceptions.

The Underwriting Agreement contains customary representations, warranties, covenants and agreements by the Company, customary conditions to closing, indemnification obligations, other obligations of the parties and termination provisions. The representations, warranties and covenants contained in the Underwriting Agreement were made only for purposes of such agreement and as of specific dates, were solely for the benefit of the parties to such agreement and may be subject to limitations agreed upon by the contracting parties. The foregoing is only a summary of the terms of the Underwriting Agreement and the Pre-Funded Warrants issued under the Underwriting Agreement, and does not purport to be complete and is qualified in its entirety by reference to the full text of (i) the form of Underwriting Agreement, a copy of which is attached to this report as Exhibit 1.1 and (ii) the form of Pre-Funded Warrant, a copy of which is attached to this report as Exhibit 4.1.

A copy of the legal opinion and consent of Sidley Austin LLP, counsel to the Company, relating to the issuance and sale of the securities in the Offering is attached as Exhibit 5.1 to this Current Report on Form 8-K.

(d) Exhibits

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.