Atara Biotherapeutics(US:ATRA) Businesswire·2026-03-31 16:08Core Viewpoint - A class action lawsuit has been filed against Atara Biotherapeutics, Inc. (ATRA) for securities fraud, affecting shareholders who acquired shares between May 20, 2024, and January 9, 2026, with a deadline for lead plaintiff motion set for May 22, 2026 [1]. Summary by Relevant Sections Company Background - Atara Biotherapeutics, Inc. is a biotechnology company focused on developing therapies for patients with serious diseases, including its Epstein-Barr treatment, tabelecleucel (EBVALLO) [4]. Events Leading to the Lawsuit - On January 16, 2025, Atara received a Complete Response Letter (CRL) from the FDA regarding its BLA for tabelecleucel, indicating that the application would not be approved in its current form, leading to a stock price drop of $5.33, or 40.5%, closing at $7.83 per share [4]. - On January 21, 2025, Atara announced a clinical hold on its active IND applications due to GMP compliance issues, resulting in a further stock price decline of $0.52, or 7.9%, to close at $6.05 per share [5]. - On January 12, 2026, Atara disclosed another CRL regarding the resubmitted tabelecleucel BLA, stating that the trial's design and conduct were inadequate for evidence of effectiveness, causing the stock price to fall by $7.79, or 56.99%, to close at $5.88 per share [6][7]. Allegations in the Lawsuit - The lawsuit alleges that Atara's management made materially false and misleading statements and failed to disclose significant adverse facts about the company's business and prospects, including: 1. Manufacturing issues and deficiencies in the ALLELE study that made FDA approval unlikely [7]. 2. Overstated regulatory prospects for tabelecleucel [7]. 3. Heightened risk of regulatory scrutiny due to manufacturing issues, jeopardizing ongoing clinical trials [7]. 4. Significant negative impacts on Atara's business and financial condition [7]. 5. Misleading positive statements regarding the company's operations and prospects [7].