SCHEDULE 13G

CUSIP No.

046513206

Names of Reporting Persons

Redmile Group, LLC

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

Sec Use Only

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 601,243.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 601,243.00

Aggregate Amount Beneficially Owned by Each Reporting Person

601,243.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Percent of class represented by amount in row (9)

9.9 %

Type of Reporting Person (See Instructions)

IA, OO

Comment for Type of Reporting Person: Redmile Group, LLC's beneficial ownership of the Issuer's common stock ("Common Stock") is comprised of 441,701 shares of Common Stock owned by certain private investment vehicles managed by Redmile Group, LLC (the "Redmile Funds"), including RedCo I, L.P. ("RedCo I") and Redmile Biopharma Investments II, L.P. ("RBI II"). Subject to the Beneficial Ownership Blocker (as defined below), Redmile Group, LLC may also be deemed to beneficially own 2,732,047 shares of Common Stock issuable upon exercise of certain pre-funded warrants to purchase Common Stock (the "Warrants"). Pursuant to the terms of the Warrants, the Issuer may not effect any exercise of the Warrant, and a holder of a Warrant does not have the right to exercise the Warrant held by such holder, to the extent that after giving effect to such issuance after exercise, the holder (together with the holder's affiliates, and any other persons acting as a group together with the holder or any of the holder's affiliates), would beneficially own in excess of 9.99% (the "Beneficial Ownership Limitation") of the number of shares of Common Stock outstanding immediately after giving effect to the issuance of shares of Common Stock issued upon exercise of the Warrant (the "Beneficial Ownership Blocker"). The Beneficial Ownership Limitation may be changed at a holder's election upon 61 days' notice to the Issuer. The 601,243 shares of Common Stock reported as beneficially owned by Redmile Group, LLC in this Schedule 13G represent 9.99% of the outstanding shares of Common Stock (calculated in accordance with the footnote below). The reported securities may be deemed beneficially owned by Redmile Group, LLC as investment manager of the Redmile Funds. The reported securities may also be deemed beneficially owned by Jeremy C. Green as the principal of Redmile Group, LLC. Redmile Group, LLC and Mr. Green each disclaim beneficial ownership of these shares, except to the extent of its or his pecuniary interest in such shares, if any. Percentage based on: (i) 5,858,909 shares of Common Stock outstanding as of March 3, 2025, as reported by the Issuer in its Form 10-K for the fiscal year ended December 31, 2024 filed with the Securities and Exchange Commission on March 7, 2025 (the "Form 10-K"); plus (ii) 159,542 shares of Common Stock issuable upon exercise of the Warrants, which due to the Beneficial Ownership Limitation is the maximum number of shares that could be issued upon exercise of the Warrants.

SCHEDULE 13G

CUSIP No.

046513206

Names of Reporting Persons

Jeremy C. Green

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

Sec Use Only

Citizenship or Place of Organization

UNITED KINGDOM

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 601,243.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 601,243.00

Aggregate Amount Beneficially Owned by Each Reporting Person

601,243.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Percent of class represented by amount in row (9)

9.9 %

Type of Reporting Person (See Instructions)

HC, IN

Comment for Type of Reporting Person: Jeremy C. Green's beneficial ownership of Common Stock is comprised of 441,701 shares of Common Stock owned by the Redmile Funds, including RedCo I and RBI II. Subject to the Beneficial Ownership Blocker, Mr. Green may also be deemed to beneficially own 2,732,047 shares of Common Stock issuable upon exercise of the Warrants. Pursuant to the terms of the Warrants, the Issuer may not effect any exercise of the Warrant, and a holder of a Warrant does not have the right to exercise the Warrant held by such holder, to the extent that the Beneficial Ownership Blocker applies. The 601,243 shares of Common Stock reported as beneficially owned by Mr. Green in this Schedule 13G represent 9.99% of the outstanding shares of Common Stock (calculated in accordance with the footnote below). The reported securities may be deemed beneficially owned by Redmile Group, LLC as investment manager of the Redmile Funds. The reported securities may also be deemed beneficially owned by Jeremy C. Green as the principal of Redmile Group, LLC. Redmile Group, LLC and Mr. Green each disclaim beneficial ownership of these shares, except to the extent of its or his pecuniary interest in such shares, if any. Percentage based on: (i) 5,858,909 shares of Common Stock outstanding as of March 3, 2025, as reported by the Issuer in the Form 10-K; plus (ii) 159,542 shares of Common Stock issuable upon exercise of the Warrants, which due to the Beneficial Ownership Limitation is the maximum number of shares that could be issued upon exercise of the Warrants.

SCHEDULE 13G

CUSIP No.

046513206

Names of Reporting Persons

RedCo I, L.P.

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

Sec Use Only

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 347,442.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 347,442.00

Aggregate Amount Beneficially Owned by Each Reporting Person

347,442.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Percent of class represented by amount in row (9)

5.8 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person: The shares of Common Stock reported as beneficially owned by RedCo I in this Schedule 13G represent the 191,226 shares of Common Stock held directly by RedCo I and the 156,216 shares of Common Stock that could be issued to RedCo I upon exercise of the Warrants directly held by RedCo I. Percentage based on: (i) 5,858,909 shares of Common Stock outstanding as of March 3, 2025, as reported by the Issuer in the Form 10-K; plus (ii) 156,216 shares of Common Stock issuable upon exercise of the Warrants directly held by RedCo I.

SCHEDULE 13G

CUSIP No.

046513206

Names of Reporting Persons

Redmile Biopharma Investments II, L.P.

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

Sec Use Only

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 302,173.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 302,173.00

Aggregate Amount Beneficially Owned by Each Reporting Person

302,173.00

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

Percent of class represented by amount in row (9)

5.0 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person: As of March 7, 2025, an increase in the issuer's outstanding Common Stock disclosed in the Form 10-K increased the capacity under the Beneficial Ownership Blocker applicable to the Warrants directly held by RBI II, and caused RBI II's beneficial ownership to exceed five percent of the issuer's outstanding Common Stock. RBI II has joined this Schedule 13G amendment to file its initial report pursuant to Rule 13d-1(d). RBI II's beneficial ownership of Common Stock is comprised of 142,631 shares of Common Stock directly held by RBI II. Subject to the Beneficial Ownership Blocker, RBI II may also be deemed to beneficially own 1,507,640 shares of Common Stock issuable upon exercise of the Warrants directly held by RBI II. Pursuant to the terms of the Warrants, the Issuer may not effect any exercise of any Warrant, and a holder of a Warrant does not have the right to exercise any portion of the Warrant held by such holder, if the Beneficial Ownership Blocker applies. The shares of Common Stock reported as beneficially owned by RBI II in this Schedule 13G represent the shares of Common Stock held directly by RBI II and the 159,542 shares of Common Stock that could be issued to RBI II upon exercise of certain of the Warrants directly held by RBI II under the Beneficial Ownership Blocker. Percentage based on: (i) 5,858,909 shares of Common Stock outstanding as of March 3, 2025, as reported by the Issuer in the Form 10-K; plus (ii) 159,542 shares of Common Stock issuable upon exercise of the Warrants directly held by RBI II, which due to the Beneficial Ownership Limitation is the maximum number of shares that could be issued upon exercise of the Warrants.

SCHEDULE 13G

Item 1.

(a)

Name of issuer:

Atara Biotherapeutics, Inc.

(b)

Address of issuer's principal executive offices:

1280 Rancho Conejo Blvd, Thousand Oaks, CA, 91320

Item 2.

(a)

Name of person filing:

Redmile Group, LLC Jeremy C. Green RedCo I, L.P. Redmile Biopharma Investments II, L.P.

(b)

Address or principal business office or, if none, residence:

Redmile Group, LLC One Letterman Drive Building D, Suite D3-300 The Presidio of San Francisco San Francisco, California 94129 Jeremy C. Green c/o Redmile Group, LLC (NY Office) 45 W. 27th Street, Floor 11 New York, NY 10001 RedCo I, L.P. c/o Redmile Group, LLC One Letterman Drive Building D, Suite D3-300 The Presidio of San Francisco San Francisco, California 94129 Redmile Biopharma Investments II, L.P. c/o Redmile Group, LLC One Letterman Drive Building D, Suite D3-300 The Presidio of San Francisco San Francisco, California 94129

(c)

Citizenship:

Redmile Group, LLC: Delaware Jeremy C. Green: United Kingdom RedCo I, L.P.: Delaware Redmile Biopharma Investments II, L.P.: Delaware

(d)

Title of class of securities:

Common Stock, par value $0.0001 per share

(e)

CUSIP No.:

046513206

Item 3.

If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:

(a)

Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);

(b)

Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);

(c)

Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);

(d)

Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);

(e)

An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);

(f)

An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);

(g)

A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);

(h)

A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i)

A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j)

A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:

(k)

Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).

Item 4.

Ownership

(a)

Amount beneficially owned:

Redmile Group, LLC - 601,243 (1) Jeremy C. Green - 601,243 (1) RedCo I, L.P. - 347,442 (2) Redmile Biopharma Investments II, L.P. - 302,173 (3)

(b)

Percent of class:

Redmile Group, LLC - 9.9% (4) Jeremy C. Green - 9.9% (4) RedCo I, L.P. - 5.8% (5) Redmile Biopharma Investments II, L.P. - 5.0% (6) %

(c)

Number of shares as to which the person has:

(i) Sole power to vote or to direct the vote:

Redmile Group, LLC - 0 Jeremy C. Green - 0 RedCo I, L.P. - 0 Redmile Biopharma Investments II, L.P. - 0

(ii) Shared power to vote or to direct the vote:

Redmile Group, LLC - 601,243 (1) Jeremy C. Green - 601,243 (1) RedCo I, L.P. - 347,442 (2) Redmile Biopharma Investments II, L.P. - 302,173 (3)

(iii) Sole power to dispose or to direct the disposition of:

Redmile Group, LLC - 0 Jeremy C. Green - 0 RedCo I, L.P. - 0 Redmile Biopharma Investments II, L.P. - 0

(iv) Shared power to dispose or to direct the disposition of:

Redmile Group, LLC - 601,243 (1) Jeremy C. Green - 601,243 (1) RedCo I, L.P. - 347,442 (2) Redmile Biopharma Investments II, L.P. - 302,173 (3) (1) Redmile Group, LLC's and Jeremy C. Green's beneficial ownership of the Issuer's Common Stock is comprised of 441,701 shares of Common Stock owned by the Redmile Funds, including RedCo I and RBI II. Subject to the Beneficial Ownership Blocker, Redmile Group, LLC and Mr. Green may also be deemed to beneficially own 2,732,047 shares of Common Stock issuable upon exercise of the Warrants. Pursuant to the terms of the Warrants, the Issuer may not effect any exercise of any Warrant, and a holder of a Warrant does not have the right to exercise any portion of the Warrant held by such holder, if the Beneficial Ownership Blocker applies. The 601,243 shares of Common Stock reported as beneficially owned by Redmile Group, LLC and Mr. Green in this Schedule 13G represent 9.99% of the outstanding shares of Common Stock (calculated in accordance with footnote (4) below). The reported securities may be deemed beneficially owned by Redmile Group, LLC as investment manager of the Redmile Funds. The reported securities may also be deemed beneficially owned by Jeremy C. Green as the principal of Redmile Group, LLC. Redmile Group, LLC and Mr. Green each disclaim beneficial ownership of these shares, except to the extent of its or his pecuniary interest in such shares, if any. (2) The shares of Common Stock reported as beneficially owned by RedCo I in this Schedule 13G represent the 191,226 shares of Common Stock held directly by RedCo I and the 156,216 shares of Common Stock that could be issued to RedCo I upon exercise of the Warrants directly held by RedCo I. (3) RBI II's beneficial ownership of Common Stock is comprised of 142,631 shares of Common Stock. Subject to the Beneficial Ownership Blocker, RBI II may also be deemed to beneficially own 1,507,640 shares of Common Stock issuable upon exercise of the Warrants directly held by RBI II. Pursuant to the terms of the Warrants, the Issuer may not effect any exercise of any Warrant, and a holder of a Warrant does not have the right to exercise any portion of the Warrant held by such holder, if the Beneficial Ownership Blocker applies. The shares of Common Stock reported as beneficially owned by RBI II in this Schedule 13G represent the shares of Common Stock held directly by RBI II and the 159,542 shares of Common Stock that could be issued to RBI II upon exercise of certain of the Warrants directly held by RBI II under the Beneficial Ownership Blocker. (4) Percentage based on: (i) 5,858,909 shares of Common Stock outstanding as of March 3, 2025, as reported by the Issuer in the Form 10-K; plus (ii) 159,542 shares of Common Stock issuable upon exercise of the Warrants, which due to the Beneficial Ownership Limitation is the maximum number of shares that could be issued upon exercise of the Warrants. (5) Percentage based on: (i) 5,858,909 shares of Common Stock outstanding as of March 3, 2025, as reported by the Issuer in the Form 10-K; plus (ii) 156,216 shares of Common Stock issuable upon exercise of the Warrants directly held by RedCo I. (6) Percentage based on: (i) 5,858,909 shares of Common Stock outstanding as of March 3, 2025, as reported by the Issuer in the Form 10-K; plus (ii) 159,542 shares of Common Stock issuable upon exercise of the Warrants directly held by RBI II, which due to the Beneficial Ownership Limitation is the maximum number of shares that could be issued upon exercise of the Warrants.

Item 5.

Ownership of 5 Percent or Less of a Class.

Item 6.

Ownership of more than 5 Percent on Behalf of Another Person.

Not Applicable

Item 7.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.

If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary.

See the response to Item 4.

Item 8.

Identification and Classification of Members of the Group.

Not Applicable

Item 9.

Notice of Dissolution of Group.

Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Redmile Group, LLC

Signature:	/s/ Jeremy C. Green
Name/Title:	Managing Member
Date:	05/15/2025

Jeremy C. Green

Signature:	/s/ Jeremy C. Green
Name/Title:	Jeremy C. Green
Date:	05/15/2025

RedCo I, L.P.

Signature:	/s/ Jeremy C. Green
Name/Title:	Managing Member of RedCo I (GP), LLC, general partner of RedCo I, L.P.
Date:	05/15/2025

Redmile Biopharma Investments II, L.P.

Signature:	/s/ Jeremy C. Green
Name/Title:	Managing Member of Redmile Biopharma Investments II (GP), LLC, general partner of Redmile Biopharma Investments II, L.P.
Date:	05/15/2025