Atara Biotherapeutics Announces Pricing of $16 Million Offering

Atara Biotherapeutics, Inc. (NASDAQ:ATRA), a leader in T-cell immunotherapy, leveraging its novel allogeneic Epstein-Barr virus (EBV) T-cell platform to develop transformative therapies for patients with cancer and autoimmune diseases, today announced the pricing of an offering of 834,237 shares of its common stock at an offering price of $6.61 per share and pre-funded warrants to purchase 1,587,108 shares of its common stock at an offering price of $6.6099 per pre-funded warrant share in an underwritten registered direct offering to a limited number of existing institutional investors, including entities affiliated with Adiumentum Capital Management, EcoR1 Capital, Panacea Venture and Redmile Group. The pre-funded warrants will have an exercise price of $0.0001 per share and will be immediately exercisable upon issuance. The offering is expected to close on or about May 16, 2025, subject to the satisfaction of customary closing conditions.

The gross proceeds from the offering are expected to be $16 million, before deducting underwriting discounts and commissions and estimated offering expenses payable by Atara. Atara currently intends to use the net proceeds from the offering to fund its ongoing activities required to achieve biologics license application (BLA) approval for tab-cel, and for working capital and general corporate purposes.

TD Cowen is acting as the sole bookrunner for the offering.

The securities described above are being offered by Atara pursuant to a shelf registration statement on Form S-3 (No. 333-275256), including a base prospectus, that was previously filed by Atara with the U.S. Securities and Exchange Commission (the "SEC") on November 1, 2023 and was declared effective on November 13, 2023. A prospectus supplement containing additional information relating to the offering will be filed with the SEC and will be available on the SEC's website located at http://www.sec.gov. Copies of the final prospectus supplement and the accompanying prospectus relating to the offering, when available, may also be obtained by contacting TD Securities (USA) LLC, 1 Vanderbilt Avenue, New York, NY 10017, by telephone at (855) 495-9846 or by email at [email protected]

This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state or jurisdiction.

About Atara Biotherapeutics, Inc.

Atara is a leader in T-cell immunotherapy, leveraging its novel allogeneic Epstein-Barr Virus (EBV) T-cell platform to develop transformative therapies for patients with cancer and autoimmune diseases. Atara is headquartered in Southern California.

Forward-Looking Statements

This press release contains or may imply "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. For example, forward-looking statements include statements regarding the completion, timing and size of the offering and the anticipated use of proceeds of the offering. Because such statements deal with future events and are based on Atara's current expectations, they are subject to various risks and uncertainties and actual results, performance or achievements of Atara could differ materially from those described in or implied by the statements in this press release. These forward-looking statements are subject to risks and uncertainties, including without limitation risks and uncertainties related to market conditions and satisfaction of customary closing conditions related to the offering, as well as those discussed in Atara's filings with the SEC, including in the "Risk Factors" and "Management's Discussion and Analysis of Financial Condition and Results of Operations" sections of the prospectus supplement and Atara's most recently filed periodic reports on Form 10-K and Form 10-Q and subsequent filings and in the documents incorporated by reference therein. Except as otherwise required by law, Atara disclaims any intention or obligation to update or revise any forward-looking statements, which speak only as of the date hereof, whether as a result of new information, future events or circumstances or otherwise.

View source version on businesswire.com: https://www.businesswire.com/news/home/20250515378429/en/

Investor and Media Relations:

Amber Daugherty

Sr. Director, Strategy and Operations

[email protected]