The Atara Biotherapeutics, Inc. class action lawsuit was filed on behalf of those who purchased or otherwise acquired Atara Biotherapeutics, Inc. (Atara) (NASDAQ: ATRA) securities between May 20, 2024 and January 9, 2026, inclusive (the “Class Period”). Captioned Jeremy Chin Zhi Kuang v. Atara Biotherapeutics, Inc., No. 26-cv-03083 (C.D. Cal.), the Atara class action lawsuit alleges that Atara and/or certain of its officers and/or directors violated federal securities laws by making false or misleading statements and/or omitted to disclose material information.
If you lost money as a result of your Atara investment and want to find out more about this action and your rights, fill out the form on this page or contact attorney Jonathan Naji, Esq. of KTMC by calling (484) 270-1453 or via e-mail at info@ktmc.com.
COMPLAINT ALLEGATION SUMMARY:
Atara develops therapies for the treatment of solid tumors, hematologic cancers, and autoimmune diseases. Its lead product candidate, tabelecleucel, also known as EBVALLO, is a T-cell immunotherapy program for the treatment of Epstein-Barr virus positive post-transplant lymphoproliferative disease (EBV+PTLD). Atara partnered with Pierre Fabre Laboratories group’s subsidiary, Pierre Fabre Medicament (collectively, “Pierre Fabre”), for tabelecleucel’s commercialization.
The complaint alleges that, throughout the Class Period, Defendants made materially false and/or misleading statements, as well as failed to disclose material facts about the company’s business, operations, and prospects. Specifically, Defendants misrepresented and/or failed to disclose that: (1) manufacturing issues and deficiencies in tabelecleucel’s Phase 3 study made it unlikely that the FDA would approve its Biologics License Application (BLA); (2) accordingly, Atara was at a heightened risk of regulatory scrutiny and its ongoing clinical trials were in jeopardy; and (3) as a result of the foregoing, Defendants’ statements about the company’s business, operations, and prospects were materially false and misleading and/or lacked a reasonable basis at all relevant times.
WHY DID ATARA’S STOCK DROP?
On January 16, 2025, Atara announced receipt of a Complete Response Letter (CLR), which was an FDA notice stating that an application will not be approved in its present form regarding the tabelecleucel BLA. On this news, Atara’s stock price fell 40.5%. A few days later, Atara issued a press release stating that “the [FDA] has placed a clinical hold on Atara’s active Investigational New Drug (IND) applications” due to “inadequately addressed GMP [good manufacturing practice] compliance issues.” The market again reacted to this revelation, and Atara’s stock dropped 7.91%.
Nearly a year later, on January 12, 2026, Atara announced that the FDA had issued another CLR in relation to tabelecleucel’s BLA, stating that “[t]he CLR indicates that the FDA is unable to approve the EBVALLOTM BLA,” after a portion of the trial was no longer found to be adequate evidence of effectiveness for the purposes of approval. Upon this revelation, Atara’s stock plummeted 56.99%.
THE LEAD PLAINTIFF PROCESS:
The Private Securities Litigation Reform Act of 1995 permits any investor who purchased or acquired Atara securities during the Class Period to seek appointment as lead plaintiff in the Atara class action lawsuit. A lead plaintiff is a representative party that acts on behalf of other class members in directing the litigation. In order to be appointed lead plaintiff, the Court must determine that the class member’s claim is typical of the claims of other class members, and that the class member will adequately represent the class. Your ability to share in any recovery is not, however, affected by the decision whether or not to serve as a lead plaintiff. Filling out the online form above or communicating with any counsel is not necessary to participate or share in any recovery achieved in this case. Any member of the purported class may move the court to serve as a lead plaintiff through counsel of his/her choice, or may choose to do nothing and remain an inactive class member.
ABOUT KESSLER TOPAZ MELTZER & CHECK, LLP:
Kessler Topaz Meltzer & Check, LLP (KTMC) is a leading U.S. plaintiff-side law firm focused on securities-fraud class actions and global investor protection. The firm represents individual investors as well as institutions, such as major pension funds, asset managers, and international investors. KTMC has led some of the largest recoveries in securities litigation and has been recognized by peers and the legal media with numerous accolades, including The National Law Journal’s Plaintiff’s Hot List and Trailblazers in Plaintiffs' Law, BTI Consulting Group’s Honor Roll of Most Feared Law Firms, The Legal Intelligencer’s Class Action Firm of the Year, Lawdragon’s Leading Plaintiff Financial Lawyers, and Law360’s Titans of the Plaintiffs Bar. The firm operates globally with offices in Pennsylvania and California. KTMC has recovered over $25 billion for our clients and the classes they represent.