Atara Biotherape SEC Filings

Atara Biotherapeutics, Inc. reported insider share sales by an officer related to tax withholding. The company’s Chief Accounting Officer, Yanina Grant-Huerta, reported three sales of Atara common stock on 11/17/2025 totaling 1,804 shares at weighted average prices between $13.186 and $13.191 per share. After these transactions, she beneficially owned 33,454 shares of common stock directly.

The filing explains that the shares were sold automatically under a sale-to-cover provision to satisfy tax withholding obligations upon the vesting of previously granted restricted stock units, with prices reflecting broker-handled sales for a group of employees on that date.

Atara Biotherapeutics (ATRA) reported Q3 2025 results marked by lower revenue and a smaller operating footprint after transferring tab-cel responsibilities to Pierre Fabre. Commercialization revenue was $3.5 million, with a net loss of $4.3 million and loss from operations of $3.6 million.

Liquidity narrowed: cash and cash equivalents were $5.7 million and short‑term investments $8.0 million at September 30, 2025. Total assets were $30.2 million against total liabilities of $66.8 million, leaving a stockholders’ deficit of $36.6 million. Deferred revenue declined to $1.0 million as the company recognized prior amounts tied to its Pierre Fabre agreements.

Management concluded that substantial doubt exists about the company’s ability to continue as a going concern and outlined plans to seek additional capital, including equity facilities, debt, and strategic transactions. During 2025, Atara completed the transfer of manufacturing, clinical, development, and regulatory responsibilities for tab‑cel to Pierre Fabre. The company noted the tab‑cel BLA is tracking toward a PDUFA target action date of January 10, 2026. Shares outstanding were 7,210,235 as of November 6, 2025.

Atara Biotherapeutics furnished a current report announcing its financial results and operational progress for the quarter ended September 30, 2025. The details are provided in a press release titled “Atara Biotherapeutics Announces Third Quarter Financial Results and Operational Progress,” included as Exhibit 99.1.

The company states this information is furnished, not filed, and is therefore not subject to Section 18 of the Exchange Act or Sections 11 and 12(a)(2) of the Securities Act, unless specifically incorporated by reference. Atara’s common stock trades on Nasdaq under the symbol ATRA.

AnhCo Nguyen, who is listed as President and CEO and a director of Atara Biotherapeutics, reported automatic sales of company common stock on 08/18/2025 to satisfy tax withholding associated with vested restricted stock units. Three sale entries total 2,958 shares disposed at weighted-average prices of approximately $11.613–$11.617 per share, leaving the reporting person with 67,889 shares beneficially owned after the transactions. The filing notes the sales were executed by a broker pursuant to a sale-to-cover provision in the award agreement and that the reported sale price is a weighted average across employees whose shares were sold.

Yanina Grant-Huerta, Chief Accounting Officer and Director of Atara Biotherapeutics (ATRA), reported automatic share sales on August 18, 2025 to satisfy tax withholding obligations tied to the vesting of previously granted restricted stock units. The filing lists three automatic dispositions executed via broker at weighted-average prices of approximately $11.61 per share, resulting in reported beneficial ownership of 35,258 shares after the transactions. The sales were executed pursuant to a sale-to-cover provision in the award agreement and the report was signed by an attorney-in-fact on August 20, 2025.

Panacea Innovation Ltd, a reporting person linked to Atara Biotherapeutics, Inc. (ATRA), acquired 55,000 shares of Atara common stock on 08/15/2025 at a weighted-average price of $12.1895 per share. After the transaction, the reporting persons disclose beneficial ownership of 1,405,000 shares held indirectly. The filing identifies Panacea Innovation Limited and James Huang (who is the sole owner of Panacea Innovation Limited) as reporting persons and explains that Panacea entities hold securities through Panacea Venture Healthcare Fund II, L.P. and Panacea Opportunity Fund I, L.P.; the filing also includes a disclaimer that the reporting persons may be deemed to share beneficial ownership but disclaim such ownership. The price reported is a weighted average of multiple purchases ranging from $11.83 to $12.44.

Amendment No. 1 to a Schedule 13D reports that a group of Panacea-related entities and James Huang together beneficially own 1,712,900 shares of Atara Biotherapeutics common stock, representing 20.0% of the 7,023,032 shares outstanding as of August 6, 2025. The position includes 307,900 warrants that are immediately exercisable but are subject to a contractual cap preventing exercise to the extent it would increase beneficial ownership above 19.99%, so the warrants cannot currently be exercised. Panacea Venture Healthcare Fund II, L.P. purchased 74,335 shares in open market transactions from July 17 through August 19, 2025 for approximately $857,000, including 19,335 shares at a weighted average $9.6391 and 55,000 shares at a weighted average $12.1895. The filing discloses the ownership chain: James Huang owns Panacea Innovation Limited, which controls the GP entities and the funds. No legal proceedings are reported.

Form 144 notice for Atara Biotherapeutics (ATRA) shows a proposed sale of 3,346 shares of common stock on 08/18/2025 through Morgan Stanley Smith Barney (Executive Services, Sandy, UT), with an aggregate market value of $41,122.34. The shares were acquired as the settlement of vested RSUs issued under an S-8 registration on 08/15/2025; 7,788 shares were received in that settlement and payment was recorded as equity compensation for services rendered. The filer disclosed a prior sale on 05/16/2025 of 3,276 shares for gross proceeds of $22,155.59. The notice includes the required representation that the seller is not aware of undisclosed material adverse information.