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Atara Biotherapeutics is registering for resale up to 400,000 shares of its common stock by HCR Molag Fund, L.P.
The shares are issuable upon exercise of a warrant that Atara issued under an amendment dated February 20, 2026 and are being registered to satisfy a covenant in that Warrant. The company will receive no proceeds from sales by the selling stockholder; Atara may receive proceeds only if the Warrant is exercised. The filing states 8,178,114 shares outstanding as of March 10, 2026 and a Beneficial Ownership Limitation that prevents exercise to the extent it would cause ownership above 4.99% (subject to increase up to 19.99% with notice and a 61‑day delay). Atara’s common stock is listed on Nasdaq and the last reported sale price in the prospectus was $6.50.
Atara Biotherapeutics, Inc. reported an insider transaction in which entities associated with Panacea funds exercised warrants to acquire common stock indirectly. Panacea Opportunity Fund I, L.P. exercised 259,163 warrants at an exercise price of $0.0001 per share, converting them into the same number of Atara common shares.
In connection with this exercise, 5 common shares were withheld at a price of $5.23 per share to cover tax obligations, a non-market disposition. Following these transactions, indirect holdings reported for these affiliated entities totaled over one million Atara common shares, while the reporting persons formally disclaim beneficial ownership beyond what may be attributed through their roles.
Atara Biotherapeutics, Inc. is registering for resale up to 400,000 shares of its common stock. These shares are issuable upon exercise of a warrant held by HCR Molag Fund, L.P., and the registration satisfies a covenant in that warrant.
Atara will receive no proceeds from resales; any proceeds go to the selling stockholder. The filing notes a Beneficial Ownership Limitation of 4.99% under the warrant, which may be adjusted up to 19.99% with notice.
Shares outstanding were 8,178,114 as of March 10, 2026. The prospectus permits public or private resale methods, hedging, short sales and transfers by successors-in-interest.
Atara Biotherapeutics registers the offer and sale of up to $11,135,981 of its common stock under a sales agreement with TD Securities (USA) LLC.
The Supplement states the offering is being made pursuant to General Instruction I.B.6 of Form S-3 and is limited by the companys aggregate market value of non-affiliate float of $33,407,943.90 (based on 4,841,731 shares held by non-affiliates as of March 10, 2026 at a price of $6.90 per share). The filing notes the last reported sales price was $6.50 on March 13, 2026.
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.