The Law Offices of Frank R. Cruz reminds investors of the upcoming May 22, 2026 deadline to participate as a lead plaintiff in the securities fraud class action lawsuit filed on behalf of investors who acquired Atara Biotherapeutics, Inc. (“Atara” or the “Company”) (NASDAQ: ATRA) securities between May 20, 2024 and January 9, 2026, inclusive (the “Class Period”).

IF YOU ARE AN INVESTOR WHO LOST MONEY ON ATARA BIOTHERAPEUTICS, INC. (ATRA), CLICK HERE TO PARTICIPATE IN THE SECURITIES FRAUD LAWSUIT.

What Happened?
On January 16, 2025, Atara disclosed that it had received a Complete Response Letter (“CRL”) from the FDA regarding the Biologics License Application (“BLA”) of the Company’s Epstein-Barr treatment, tabelecleucel (also referred to as EBVALLO), and that the application would not be approved in its current form, stating that “[t]he CRL was solely related to observations as part of a standard pre-license inspection of a third-party manufacturing facility for EBVALLO.”

On this news, Atara’s stock price fell $5.33, or 40.5%, to close at $7.83 per share on January 16, 2025, thereby injuring investors.

Then, on January 21, Atara disclosed that the FDA had “placed a clinical hold on Atara’s active Investigational New Drug (IND) applications” due to “inadequately addressed GMP [good manufacturing practice] compliance issues identified during the pre-license inspection of the third-party manufacturing facility referenced in the [CRL]” issued in connection with the tabelecleucel BLA.

On this news, Atara’s stock price fell $0.52, or 7.9%, to close at $6.05 per share on January 21, 2025.

Finally, on January 12, 2026, Atara disclosed that the FDA had issued another CRL regarding the resubmitted tabelecleucel BLA stating that “[t]he CRL indicates that the FDA is unable to approve the EBVALLO™ BLA in its present form” because “the single arm ALLELE trial . . . is no longer considered to be adequate to provide evidence of effectiveness for accelerated approval” and “the trial’s interpretability is confounded due to trial study design, conduct, and analysis.”

On this news, Atara’s stock price fell $7.79, or 56.99%, to close at $5.88 per share on January 12, 2026, thereby injuring investors further.

What Is The Lawsuit About?
The complaint filed in this class action alleges that throughout the Class Period, Defendants made materially false and/or misleading statements, as well as failed to disclose material adverse facts about the Company’s business, operations, and prospects. Specifically, Defendants failed to disclose to investors that: (1) certain manufacturing issues, as well as deficiencies inherent in the ALLELE study, made it unlikely that the FDA would approve the tabelecleucel BLA; (2) accordingly, tabelecleucel’s regulatory prospects were overstated; (3) the aforementioned manufacturing issues also subjected Atara to a heightened risk of regulatory scrutiny, as well as jeopardized its ongoing clinical trials; (4) all the foregoing was likely to have a significant negative impact on Atara’s business and financial condition; and (5) as a result, Defendants’ positive statements about the Company’s business, operations, and prospects were materially misleading and/or lacked a reasonable basis at all relevant times.

If you purchased or otherwise acquired Atara securities between May 20, 2024 and January 9, 2026, the deadline to seek appointment as the lead plaintiff in the securities fraud class action is May 22, 2026.

Contact Us To Participate or Learn More:
If you wish to learn more about this class action, or if you have any questions concerning this announcement or your rights or interests with respect to the pending class action lawsuit, please contact us:
Frank R. Cruz
The Law Offices of Frank R. Cruz,
2121 Avenue of the Stars, Suite 800,
Century City, California 90067
Email us at: info@frankcruzlaw.com
Call us at: 310-914-5007
Visit our website at www.frankcruzlaw.com
Follow us for updates on Twitter: twitter.com/FRC_LAW

If you inquire by email, please include your mailing address, telephone number, and number of shares purchased.

To be a member of the class action you need not take any action at this time; you may retain counsel of your choice or take no action and remain an absent member of the class action. This press release may be considered Attorney Advertising in some jurisdictions under the applicable law and ethical rules.

View source version on businesswire.com: https://www.businesswire.com/news/home/20260520208593/en/