Welcome to our dedicated page for Atara Biotherapeutics SEC filings (Ticker: ATRA), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
Atara Biotherapeutics' SEC filings document the company's allogeneic EBV T-cell immunotherapy business, public common stock, and regulatory record for tabelecleucel, including 8-K disclosures tied to FDA communications, Complete Response Letter updates, and the EBVALLO Biologics License Application.
The filings also report financial results and liquidity updates, commercialization and milestone arrangements, amendments to royalty-related purchase and sale agreements, warrant issuance terms, Nasdaq continued-listing compliance notices, and proxy matters such as board elections, executive compensation, equity awards, and shareholder voting proposals.
Atara Biotherapeutics’ annual report centers on tab-cel/Ebvallo, deep restructuring, and heavy reliance on its Pierre Fabre partnership. Tab-cel is approved as Ebvallo in the EU, UK and Switzerland and is in U.S. Phase 3 development for EBV+ PTLD, but the U.S. BLA has twice received FDA Complete Response Letters, most recently in January 2026, questioning the pivotal ALLELE trial’s adequacy.
Atara has progressively transferred manufacturing, clinical, development and regulatory responsibility for tab-cel worldwide to Pierre Fabre in exchange for upfront and milestone payments and double‑digit tiered royalties, while remaining eligible for up to $308M in milestones in the original territory and $556M in additional territories.
The company has exited its CAR‑T programs ATA3219 and ATA3431, returned multiple partnered programs, and executed successive workforce reductions throughout 2025, leaving about 15 employees to manage strategic priorities. The board is actively exploring strategic alternatives, including potential business combinations or asset sales, and warns of substantial ongoing losses, limited commercialization revenue and the need for significant near‑term financing, with liquidation or wind‑down cited as possible outcomes.
Atara Biotherapeutics reported a sharp turnaround in 2025, posting net income of $32.7 million or $2.61 per share, compared with a net loss of $85.4 million in 2024. Commercialization revenue was $120.8 million, slightly below $128.9 million a year earlier, but total costs and operating expenses fell to $84.9 million from $212.4 million as research and development and general and administrative spending were significantly reduced.
Cash, cash equivalents and short-term investments were $8.5 million as of December 31, 2025, down from $42.5 million a year earlier, yet the company expects this balance, together with $3.0 million of recent at-the-market proceeds and 2025 efficiencies, to fund operations through year-end 2026. Atara also amended its agreement with HealthCare Royalty, pushing a $9.0 million milestone payment from June 30, 2026 to January 1, 2028 in exchange for a warrant to purchase up to 400,000 shares. A Type A meeting has been scheduled for partner Pierre Fabre Pharmaceuticals and the FDA to discuss the Complete Response Letter for tabelecleucel, with a regulatory update anticipated in the second quarter.
Atara Biotherapeutics reported that the U.S. Food and Drug Administration has granted a Type A meeting to discuss the Complete Response Letter for the EBVALLO™ Biologics License Application for tabelecleucel (tab-cel), which is held by its partner Pierre Fabre Pharmaceuticals. Atara will support Pierre Fabre in addressing FDA feedback using additional efficacy data collected since the original submission to enable a resubmission. The company stated it anticipates providing a further regulatory update in the second quarter.
Nguyen AnhCo reported acquisition or exercise transactions in this Form 4 filing.
Atara Biotherapeutics reported that President and CEO Nguyen AnhCo received a grant of 81,100 shares of common stock in the form of restricted stock units at no cash cost. These RSUs vest in eight equal quarterly installments beginning on the second Quarterly Vesting Date after March 9, 2026, and then on subsequent March 1, May 15, August 15, and November 15 vesting dates, subject to continued employment. Following this award, AnhCo directly holds 143,078 shares of Atara common stock.
Grant-Huerta Yanina reported acquisition or exercise transactions in this Form 4 filing.
Atara Biotherapeutics reported that Chief Accounting Officer Yanina Grant-Huerta received a grant of 20,300 restricted stock units (RSUs) of common stock at no cost. Following this award, she holds 52,050 shares of common stock directly.
The RSUs vest in eight equal installments of one-eighth each. Vesting begins on the second Quarterly Vesting Date after March 9, 2026 and continues on the next seven Quarterly Vesting Dates, subject to her continuous employment. Quarterly Vesting Dates are March 1, May 15, August 15, and November 15, or the first business day thereafter.
Atara Biotherapeutics Chief Accounting Officer Yanina Grant-Huerta reported open-market sales of 2,104 shares of common stock on March 2, 2026. The shares were sold automatically to cover tax withholding on vesting restricted stock units at weighted average prices around $5.08 per share. Following these transactions, she directly holds 31,750 shares, including 400 shares acquired through the company’s employee stock purchase plan.
Atara Biotherapeutics President and CEO Nguyen AnhCo sold 2,996 shares of common stock on March 2, 2026 to cover tax withholding on vested restricted stock units.
The shares were sold in open-market transactions at weighted average prices around $5.08 per share, and he now directly holds 61,978 common shares.
Atara Biotherapeutics reported that its partner Pierre Fabre Pharmaceuticals has requested a Type A meeting with the U.S. Food and Drug Administration to discuss tabelecleucel (tab-cel). The meeting request follows the Complete Response Letter for the EBVALLO™ Biologics License Application dated January 9, 2026.
Atara states that a briefing book was submitted to the FDA addressing points in the letter, including arguments that the ALLELE study was adequate, well-controlled, and sufficient to support the application. The briefing materials also summarize updated longer-term efficacy data from ALLELE, additional supportive data from the development program, and post-marketing data in Europe that may be used in a potential resubmission.
ATRA reported a Rule 144 notice to sell 7,788 shares of Common Stock. The filing shows these shares relate to the settlement of vested RSUs issued under an S-8 registration plan and are dated 03/01/2026.
The filing lists the transaction as equity compensation for services rendered and identifies Morgan Stanley Smith Barney LLC Executive Services as the broker.
Issuer files a Form 144 notice to sell 4,759 shares of common stock. The filing states these shares result from the settlement of vested RSUs issued under an S-8 registration plan on 03/01/2026. The submission appears as a routine insider resale notice under applicable resale rules.