Law Offices of Howard G. Smith reminds investors of the upcoming May 22, 2026 deadline to file a lead plaintiff motion in the case filed on behalf of investors who purchased 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 SUFFERED A LOSS IN ATARA BIOTHERAPEUTICS, INC. (ATRA), CONTACT THE LAW OFFICES OF HOWARD G. SMITH TO PARTICIPATE IN THE ONGOING SECURITIES FRAUD LAWSUIT.

Contact the Law Offices of Howard G. Smith to discuss your legal rights by email at howardsmith@howardsmithlaw.com, by telephone at (215) 638-4847 or visit our website at www.howardsmithlaw.com.

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 during the Class Period, you may move the Court no later than May 22, 2026 to ask the Court to appoint you as lead plaintiff if you meet certain legal requirements.

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 these matters, please contact us:

Law Offices of Howard G. Smith,
3070 Bristol Pike, Suite 112,
Bensalem, Pennsylvania 19020,
Telephone: (215) 638-4847
Email: howardsmith@howardsmithlaw.com,
Visit our website at: www.howardsmithlaw.com.

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.

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