# EDGAR Filing Document

**Accession Number:** 0001604464
**File Stem:** 0001193125-26-000907
**Filing Date:** 2026-1
**Character Count:** 10421
**Document Hash:** 0014ad7720ef2fbd28768b0b8d3fdbaa
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-000907.hdr.sgml**: 20260102

**ACCESSION NUMBER**: 0001193125-26-000907

**CONFORMED SUBMISSION TYPE**: 8-K

**PUBLIC DOCUMENT COUNT**: 13

**CONFORMED PERIOD OF REPORT**: 20251230

**ITEM INFORMATION**: Entry into a Material Definitive Agreement

**ITEM INFORMATION**: Financial Statements and Exhibits

**FILED AS OF DATE**: 20260102

**DATE AS OF CHANGE**: 20260102

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Atara Biotherapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001604464
- **STANDARD INDUSTRIAL CLASSIFICATION:** BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 460920988
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 8-K
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-36548
- **FILM NUMBER:** 26502310

**BUSINESS ADDRESS:**
- **STREET 1:** 1280 RANCHO CONEJO BLVD
- **CITY:** THOUSAND OAKS
- **STATE:** CA
- **ZIP:** 91320
- **BUSINESS PHONE:** 805-623-4211

**MAIL ADDRESS:**
- **STREET 1:** 1280 RANCHO CONEJO BLVD
- **CITY:** THOUSAND OAKS
- **STATE:** CA
- **ZIP:** 91320

?xml version='1.0' encoding='ASCII'? 8-K

### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### WASHINGTON, D.C. 20549

### FORM 8-K

#### CURRENT REPORT

#### Pursuant to Section 13 or 15(d)

#### of the Securities Exchange Act of 1934

#### Date of Report (Date of earliest event reported): December 30, 2025

## Atara Biotherapeutics, Inc.

#### (Exact name of Registrant as Specified in Its Charter)

---

| | | |
|:---|:---|:---|
| **Delaware** | **001-36548** | **46-0920988** |
| **(State or Other Jurisdiction<br>of Incorporation)** | **(Commission**<br> **File Number)** | **(IRS Employer<br>Identification No.)** |

---

---

| | |
|:---|:---|
| **1280 Rancho Conejo Blvd** |  |
| **Thousand Oaks, California** | **91320** |
| **(Address of Principal Executive Offices)** | **(Zip Code)** |

---

#### Registrant's Telephone Number, Including Area Code: (805) 623-4211

#### (Former Name or Former Address, if Changed Since Last Report)
Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

#### Securities registered pursuant to Section 12(b) of the Act:

---

| | | |
|:---|:---|:---|
| **Title of each class** | **Trading<br>Symbol(s)** | **Name of each exchange<br>on which registered** |
| Common Stock, par value $0.0001 per share | ATRA | The Nasdaq Stock Market LLC |

---

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

------

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| | |
|:---|:---|
| **Item 1.01** | **Entry into a Material Definitive Agreement.**  |

---

On December 30, 2025, Atara Biotherapeutics, Inc., (the "Company") entered into the Fourth Amendment (the "Amendment") to the Amended and Restated Commercialization Agreement dated October 31, 2023 (the "Agreement") with Pierre Fabre Medicament ("Pierre Fabre"). Under the terms of the Amendment, the Company has agreed to reduce the aggregate amount of potential milestone payments payable by Pierre Fabre to the Company upon achieving certain regulatory milestones relating to the approval by the FDA of a BLA for tab-cel from $40.0 million to $31.0 million for the right to receive an additional $15.0 million potential milestone payment from Pierre Fabre to the Company upon achieving a certain commercial milestone.

The foregoing summary of the Amendment does not purport to be complete and is qualified in its entirety by reference to the Amendment, a copy of which is filed herewith as Exhibit 10.1 to this Current Report on Form 8-K and is incorporated by reference into this Item 1.01.

---

| | |
|:---|:---|
| **Item 9.01** | **Financial Statements and Exhibits**  |

---

(d) Exhibits.

---

| | |
|:---|:---|
| **Exhibit**<br> **No.** | **Description** |
| 10.1 | [Fourth Amendment to the Amended and Restated Commercialization Agreement, by and between Atara Biotherapeutics, Inc. and Pierre Fabre Medicament, dated December 30, 2025](d90230dex101.htm) |
| 104 | Cover Page Interactive Data File (embedded within the Inline XBRL document). |

---

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#### SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

---

| | | |
|:---|:---|:---|
|  |  | ATARA BIOTHERAPEUTICS, INC. |
| Date: January 2, 2026 | By: | /s/ AnhCo Thieu Nguyen |
|  |  | AnhCo Thieu Nguyen |
|  |  | President and Chief Executive Officer |
|  |  | (Duly Authorized Officer and Principal Executive Officer) |

---

## Exhibit 10.1

**Exhibit 10.1** 

CONFIDENTIAL

**[\*\*\*] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY [\*\*\*], HAS BEEN OMITTED BECAUSE IT IS NOT MATERIAL, AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL** 

**FOURTH AMENDMENT TO** 

**THE AMENDED AND RESTATED COMMERCIALIZATION AGREEMENT** 

This **FOURTH AMENDMENT TO THE AMENDED AND RESTATED COMMERCIALIZATION AGREEMENT** (the "**<u>4</u><u><sup>th</sup></u> <u>Amendment</u>**"), is entered into as of December 30, 2025 (the "**<u>Amendment Effective Date</u>**"), by and between Atara Biotherapeutics, Inc. ("**<u>Atara</u>**") and Pierre Fabre Medicament ("**<u>Partner</u>**"). Atara and Partner are referred to in this Amendment individually as a "**<u>Party</u>**" and collectively as the "**<u>Parties</u>**".

**RECITALS** 

**WHEREAS**, Atara and Partner entered into that certain Amended and Restated Commercialization Agreement, dated as of October 31, 2023, and effective as of December 19, 2023, as amended (the "**<u>Agreement</u>**");

**WHEREAS**, pursuant to the Agreement, Atara granted to Partner and its Affiliates an exclusive, worldwide, remuneration-bearing license, including the right to commercialize the Product (for which Atara submitted a BLA to the U.S. Food and Drug Administration on May 20, 2024) in the United States;

**WHEREAS**, the Parties have mutually agreed to amend the Agreement as follows, in accordance with <u>Section</u> <u>16.3</u> of the Agreement;

**NOW, THEREFORE**, in consideration of the various promises and undertakings set forth herein, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, and on the terms and subject to the conditions set forth herein, the Parties hereby agree as follows:

**AMENDMENT** 

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1. Capitalized terms used and not otherwise defined herein shall have the respective meanings given to such terms in the Agreement.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2. <u>Section 10.2(g)</u> of the Agreement is hereby deleted in its entirety and replaced with the following:

[\*\*\*].

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3. <u>Section 10.2(h)</u> of the Agreement is hereby deleted in its entirety and replaced with the following:

[\*\*\*].

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;4. A new <u>Section</u> <u>10.3(k)</u> of the Agreement is hereby added as follows:

[\*\*\*] Product Net Sales exceed [\*\*\*]: Fifteen Million Dollars ($15,000,000) [\*\*\*].

------

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;5. Except as specifically modified or waived herein, all other terms and conditions of the Agreement are unchanged and shall remain in full force and effect. In the event of any conflict or inconsistency between the terms of in this Amendment and the Agreement, the terms of this Amendment will control.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;6. No waiver, alteration or modification of any of the provisions of this Amendment shall be binding unless made in writing and signed by the Parties.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;7. This Amendment may be executed in any number of counterparts and by each of the Parties in separate counterparts, each of which when so executed shall be deemed to be an original and all of which taken together shall constitute one and the same agreement. Signatures of the Parties transmitted by electronic means shall be deemed to be their original signatures for all purposes.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;8. This Amendment will be governed by and in accordance with the laws of Switzerland without giving effect to any choice of law principles that would require the application of the laws of a different jurisdiction.

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;9. Any dispute arising out of or relating to this Fourth Amendment shall be resolved in accordance with the venue and dispute resolution provisions of Section 16.12 of the Agreement.

*[Signature Page Follows]* 

------

IN WITNESS WHEREOF, the Parties intending to be bound have caused this 4<sup>TH</sup> Amendment to be executed by their duly authorized representatives as of the Amendment Effective Date.

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| | | | |
|:---|:---|:---|:---|
| **ATARA BIOTHERAPEUTICS, INC.** | **ATARA BIOTHERAPEUTICS, INC.** | **PIERRE FABRE MEDICAMENT** | **PIERRE FABRE MEDICAMENT** |
| By: | /s/ Cokey Nguyen | By: | /s/ Marie Andree Gamache |
| Name: Cokey Nguyen | Name: Cokey Nguyen | Name: Marie Andree Gamache | Name: Marie Andree Gamache |
| Title: President and CEO | Title: President and CEO | Title: Medical Care CEO and PFM President | Title: Medical Care CEO and PFM President |
| Date: 12/30/2025 | Date: 12/30/2025 | Date: 12/30/2025 | Date: 12/30/2025 |

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