Key Takeaways:
Multiple law firms have filed a class-action lawsuit against Atara Biotherapeutics, Inc. after the company’s stock plunged 57% following the rejection of its lead drug candidate, tabelecleucel.
"The lawsuit alleges that... defendants made false and/or misleading statements and/or failed to disclose... certain manufacturing issues, as well as deficiencies inherent in the ALLELE study, made it unlikely that the FDA would approve the tabelecleucel BLA," according to a press release from The Portnoy Law Firm.
The complaint highlights three major stock drops. On January 16, 2025, the stock fell 40.5% after the company received a Complete Response Letter (CRL) from the FDA. It dropped another 8% on January 21, 2025, after a clinical hold was placed on the drug's applications. The largest drop of 57% occurred on January 12, 2026, when the FDA issued a second CRL.
The class period for the lawsuit covers investors who purchased Atara securities between May 20, 2024, and January 9, 2026. The lead plaintiff deadline is May 22, 2026. The lawsuit seeks to recover damages for investors who suffered losses due to the alleged misrepresentations.
The core of the lawsuit is the claim that Atara overstated the regulatory prospects of tabelecleucel, a treatment for Epstein-Barr virus-positive lymphoproliferative disease. The FDA's rejection letters cited issues with a third-party manufacturing facility and the design of the pivotal ALLELE study.
Law firms including The Portnoy Law Firm, Bronstein, Gewirtz & Grossman, LLC, and Rosen Law Firm are representing investors. They claim that the company's public statements were materially false and misleading.
The series of negative announcements has had a devastating impact on Atara's valuation, wiping out hundreds of millions of dollars in market capitalization. The stock, which traded as high as $13.67 during the class period, closed at $5.88 after the second CRL.
The lawsuits create significant legal and financial uncertainty for Atara Biotherapeutics. Investors will be closely watching for the company's response to the allegations and any further developments in the case before the May 22, 2026 lead plaintiff deadline.
This article is for informational purposes only and does not constitute investment advice.
