SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 5)

Arcellx, Inc.

(Name of Issuer)

Common Stock $0.001 par value per share

(Title of Class of Securities)

03940C100

(CUSIP Number)

Stephanie Brecher
New Enterprise Associates, 1954 Greenspring Drive, Suite 600
Timonium, MD, 21093
(410)842-4000

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

02/22/2026

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. Checkbox not checked

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP No.

03940C100

Name of reporting person

New Enterprise Associates 15, L.P.

Check the appropriate box if a member of a Group (See Instructions)

(a)

(b)

SEC use only

Source of funds (See Instructions)

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

Checkbox not checked

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 3,045,262.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 3,045,262.00

Aggregate amount beneficially owned by each reporting person

3,045,262.00

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in Row (11)

5.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13D

CUSIP No.

03940C100

Name of reporting person

NEA Partners 15, L.P.

Check the appropriate box if a member of a Group (See Instructions)

(a)

(b)

SEC use only

Source of funds (See Instructions)

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

Checkbox not checked

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 3,045,262.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 3,045,262.00

Aggregate amount beneficially owned by each reporting person

3,045,262.00

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in Row (11)

5.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13D

CUSIP No.

03940C100

Name of reporting person

NEA 15 GP, LLC

Check the appropriate box if a member of a Group (See Instructions)

(a)

(b)

SEC use only

Source of funds (See Instructions)

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

Checkbox not checked

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 3,045,262.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 3,045,262.00

Aggregate amount beneficially owned by each reporting person

3,045,262.00

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in Row (11)

5.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13D

CUSIP No.

03940C100

Name of reporting person

Forest Baskett

Check the appropriate box if a member of a Group (See Instructions)

(a)

(b)

SEC use only

Source of funds (See Instructions)

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

Checkbox not checked

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 3,045,262.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 3,045,262.00

Aggregate amount beneficially owned by each reporting person

3,045,262.00

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in Row (11)

5.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13D

CUSIP No.

03940C100

Name of reporting person

Anthony A. Florence, Jr.

Check the appropriate box if a member of a Group (See Instructions)

(a)

(b)

SEC use only

Source of funds (See Instructions)

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

Checkbox not checked

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 3,045,262.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 3,045,262.00

Aggregate amount beneficially owned by each reporting person

3,045,262.00

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in Row (11)

5.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13D

CUSIP No.

03940C100

Name of reporting person

Mohamad H. Makhzoumi

Check the appropriate box if a member of a Group (See Instructions)

(a)

(b)

SEC use only

Source of funds (See Instructions)

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

Checkbox not checked

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 3,045,262.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 3,045,262.00

Aggregate amount beneficially owned by each reporting person

3,045,262.00

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in Row (11)

5.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13D

CUSIP No.

03940C100

Name of reporting person

Scott D. Sandell

Check the appropriate box if a member of a Group (See Instructions)

(a)

(b)

SEC use only

Source of funds (See Instructions)

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

Checkbox not checked

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 7,910.00
8	Shared Voting Power 3,047,450.00
9	Sole Dispositive Power 7,910.00
10	Shared Dispositive Power 3,047,450.00

Aggregate amount beneficially owned by each reporting person

3,055,360.00

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in Row (11)

5.3 %

Type of Reporting Person (See Instructions)

SCHEDULE 13D

Item 1.

Security and Issuer

(a)

Title of Class of Securities:

Common Stock $0.001 par value per share

(b)

Name of Issuer:

Arcellx, Inc.

(c)

Address of Issuer's Principal Executive Offices:

800 Bridge Parkway, Redwood City, CALIFORNIA , 94065.

Item 1 Comment:

This Amendment No. 5 ("Amendment No. 5") to Schedule 13D amends and supplements the Schedule 13D originally filed on February 17, 2022 (the "Schedule 13D"), Amendment No. 1 thereto filed on January 24, 2023 ("Amendment No. 1"), Amendment No. 2 thereto filed on June 23, 2023 ("Amendment No. 2"), Amendment No. 3 thereto filed on May 12, 2025 ("Amendment No. 3") and Amendment No. 4 thereto filed on August 14, 2025 ("Amendment No. 4"), relating to the Common Stock of the Issuer. Certain terms used but not defined in this Amendment No. 5 have the meanings assigned thereto in the Schedule 13D (and Amendment No. 1, Amendment No. 2, Amendment No. 3 and Amendment No. 4 thereto). Except as specifically provided herein, this Amendment No. 5 does not modify any of the information previously reported on the Schedule 13D (and Amendment No. 1, Amendment No. 2, Amendment No. 3 and Amendment No. 4 thereto).

Item 2.

Identity and Background

(a)

New Enterprise Associates 15, L.P. ("NEA 15"), NEA Partners 15, L.P. ("NEA Partners 15"), which is the sole general partner of NEA 15; and NEA 15 GP, LLC ("NEA 15 LLC" and, together with NEA Partners 15, the "Control Entities"), which is the sole general partner of NEA Partners 15; and Forest Baskett ("Baskett"), Anthony A. Florence, Jr. ("Florence"), Mohamad H. Makhzoumi ("Makhzoumi") and Scott D. Sandell ("Sandell") (together, the "Managers"). The Managers are the managers of NEA 15 LLC. The persons named in this Item 2 are referred to individually herein as a "Reporting Person" and collectively as the "Reporting Persons."

(b)

The address of the principal business office of NEA 15, each Control Entity and Sandell is New Enterprise Associates, 1954 Greenspring Drive, Suite 600, Timonium, MD 21093. The address of the principal business office of Baskett and Makhzoumi is New Enterprise Associates, 2855 Sand Hill Road, Menlo Park, CA 94025. The address of the principal business office of Florence is New Enterprise Associates, 104 5th Avenue, 19th Floor, New York, NY 10011.

(c)

The principal business of NEA 15 is to invest in and assist growth-oriented businesses located principally in the United States. The principal business of NEA Partners 15 is to act as the sole general partner of NEA 15. The principal business of NEA 15 LLC is to act as the sole general partner of NEA Partners 15. The principal business of each of the Managers is to manage the Control Entities and a number of affiliated partnerships with similar businesses.

(d)

During the five years prior to the date hereof, none of the Reporting Persons has been convicted in a criminal proceeding or has been a party to a civil proceeding ending in a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

(e)

(f)

NEA 15 LLC is a limited liability company organized under the laws of the State of Delaware. NEA 15 and NEA Partners 15 are limited partnerships organized under the laws of the State of Delaware. Each of the Managers is a United States citizen.

Item 3.

Source and Amount of Funds or Other Consideration

Not applicable.

Item 4.

Purpose of Transaction

On February 22, 2026, the Issuer entered into an Agreement and Plan of Merger (the "Merger Agreement") with Gilead Sciences, Inc., a Delaware corporation ("Parent") and Ravens Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Parent ("Purchaser), pursuant to which Purchaser will commence a tender offer (the "Offer") to acquire all of the issued and outstanding shares of Common Stock of the Issuer in exchange for (i) $115.00 per share of Common Stock, net to the seller in cash, without interest, subject to any applicable withholding tax, and (ii) one contractual contingent value right ("CVR"), which represents the right to receive one contingent payment of $5.00 per CVR, in cash, without interest, upon the achievement of a specified milestone in accordance with the terms and subject to the conditions of a contingent value rights agreement, to be entered into with a rights agent selected by Parent and reasonably acceptable to the Issuer. As soon as practicable following the consummation of the Offer and subject to the terms and conditions of the Merger Agreement, Purchaser will merge with and into the Issuer, with the Issuer being the surviving corporation (the "Merger"). In connection with the Merger Agreement, NEA 15 and certain other stockholders of the Issuer (each, a "Stockholder" and together, the "Stockholders") entered into tender and support agreements (collectively, the "Support Agreements") with Parent pursuant to which each Stockholder agreed, among other things, and subject to the terms and conditions of the Support Agreements, to (i) tender all of its shares, (ii) vote against other proposals to acquire the Issuer and for any proposal for the Merger and (iii) certain other restrictions on its ability to take actions with respect to the Issuer and its shares. The Support Agreements will automatically terminate upon certain events, including the termination of the Merger Agreement. The foregoing descriptions of the Merger Agreement and the Support Agreements are qualified in their entirety by reference to the full text of such agreements. The Merger Agreement and the form of Support Agreement are included as Exhibit 2.1 and Exhibit 10.1, respectively, of Issuer's Form 8-K, filed with the Securities and Exchange Commission ("SEC") on February 23, 2026 and are incorporated herein by reference. NEA 15 now holds a total of 3,045,262 shares of Common Stock (the "NEA 15 Shares"). As a result of the Support Agreements, the Reporting Persons may be deemed to be members of a "group" with the parties to the Support Agreements. * Subject to the terms of the Support Agreements and depending on market conditions, its continuing evaluation of the business and prospects of the Issuer and other factors, NEA 15 and the other Reporting Persons may dispose of or acquire additional shares of the Issuer. Except as set forth above, none of the Reporting Persons has any present plans which relate to or would result in: (a) The acquisition by any person of additional securities of the Issuer, or the disposition of securities of the Issuer; (b) An extraordinary corporate transaction, such as a merger, reorganization or liquidation, involving the Issuer or any of its subsidiaries; (c) A sale or transfer of a material amount of assets of the Issuer or any of its subsidiaries; (d) Any change in the present board of directors or management of the Issuer, including any plans or proposals to change the number or term of directors or to fill any existing vacancies on the board; (e) Any material change in the present capitalization or dividend policy of the Issuer; (f) Any other material change in the Issuer's business or corporate structure; (g) Changes in the Issuer's charter, bylaws or instruments corresponding thereto or other actions which may impede the acquisition of control of the Issuer by any person; (h) Causing a class of securities of the Issuer to be delisted from a national securities exchange or to cease to be authorized to be quoted in an inter-dealer quotation system of a registered national securities association; (i) A class of equity securities of the Issuer becoming eligible for termination of registration pursuant to Section 12(g)(4) of the Securities Exchange Act of 1934; or (j) Any action similar to any of those enumerated above. * See the Schedule 13D or 13G (or an amendment thereto to the extent any material change in the facts set forth in any Schedule 13D or 13G previously filed by any other Stockholder has occurred) filed, or that the Reporting Persons anticipate will be filed, separately by each Stockholder, which includes, or will include, information regarding the other Stockholder's jurisdiction of organization, principal business and address of principal office.

Item 5.

Interest in Securities of the Issuer

(a)

NEA 15 is the record owner of the NEA 15 Shares (as defined below). As the general partner of NEA 15, NEA Partners 15 may be deemed to own beneficially the NEA 15 Shares. As the sole general partner of NEA Partners 15, NEA 15 LLC may be deemed to own beneficially the NEA 15 Shares. As members of NEA 15 LLC, each of the Managers may be deemed to own beneficially the NEA 15 Shares. Each Reporting Person disclaims beneficial ownership of the NEA 15 Shares other than those shares which such person owns of record. The percentage of outstanding Common Stock of the Issuer which may be deemed to be beneficially owned by each Reporting Person is set forth on Line 13 of such Reporting Person's cover sheet. Such percentage was calculated based on 57,822,871 shares of Common Stock reported by the Issuer to be outstanding as of October 31, 2025, on the Issuer's Form 10-Q filed with the SEC on November 5, 2025.

(b)

Regarding the number of shares as to which such person has: (i) sole power to vote or to direct the vote: See line 7 of cover sheets (ii) shared power to vote or to direct the vote: See line 8 of cover sheets (iii) sole power to dispose or to direct the disposition: See line 9 of cover sheets (iv) shared power to dispose or to direct the disposition: See line 10 of cover sheets.

(c)

Except as set forth in Item 4 above, none of the Reporting Persons has effected any transaction in the NEA 15 Shares during the last 60 days.

(d)

No other person is known to have the right to receive or the power to direct the receipt of dividends from, or any proceeds from the sale of, Common Stock beneficially owned by any of the Reporting Persons.

(e)

Not applicable.

Item 6.

Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer

The information provided and incorporated by reference in Item 4 is hereby incorporated by reference.

Item 7.

Material to be Filed as Exhibits.

Exhibit 1 - Agreement regarding filing of joint Schedule 13D. Exhibit 2 - Power of Attorney regarding filings under the Securities Exchange Act of 1934, as amended

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.

New Enterprise Associates 15, L.P.

Signature:	/s/ Zachary Bambach
Name/Title:	Zachary Bambach as attorney-in-fact for Anthony A. Florence Jr., Managing Partner and Co-Chief Executive Officer
Date:	02/24/2026

Signature:	/s/ Zachary Bambach
Name/Title:	Zachary Bambach as attorney-in-fact for Mohamad H. Makhzoumi, Managing Partner and Co-Chief Executive Officer
Date:	02/24/2026

NEA Partners 15, L.P.

Signature:	/s/ Zachary Bambach
Name/Title:	Zachary Bambach as attorney-in-fact for Anthony A. Florence Jr., Managing Partner and Co-Chief Executive Officer
Date:	02/24/2026

Signature:	/s/ Zachary Bambach
Name/Title:	Zachary Bambach as attorney-in-fact for Mohamad H. Makhzoumi, Managing Partner and Co-Chief Executive Officer
Date:	02/24/2026

NEA 15 GP, LLC

Signature:	/s/ Zachary Bambach
Name/Title:	Zachary Bambach as attorney-in-fact for Anthony A. Florence Jr., Managing Partner and Co-Chief Executive Officer
Date:	02/24/2026

Signature:	/s/ Zachary Bambach
Name/Title:	Zachary Bambach as attorney-in-fact for Mohamad H. Makhzoumi, Managing Partner and Co-Chief Executive Officer
Date:	02/24/2026

Forest Baskett

Signature:	/s/ Zachary Bambach
Name/Title:	Zachary Bambach as attorney-in-fact for Forest Baskett
Date:	02/24/2026

Anthony A. Florence, Jr.

Signature:	/s/ Zachary Bambach
Name/Title:	Zachary Bambach as attorney-in-fact for Anthony A. Florence Jr.
Date:	02/24/2026

Mohamad H. Makhzoumi

Signature:	/s/ Zachary Bambach
Name/Title:	Zachary Bambach as attorney-in-fact for Mohamad H. Makhzoumi
Date:	02/24/2026

Scott D. Sandell

Signature:	/s/ Zachary Bambach
Name/Title:	Zachary Bambach as attorney-in-fact for Scott D. Sandell
Date:	02/24/2026

Comments accompanying signature:

This Amendment No. 5 to Schedule 13D was executed by Zachary Bambach on behalf of the individuals listed above pursuant to a Power of Attorney, a copy of which is attached as Exhibit 2.

Amendment: SEC Form SCHEDULE 13D/A filed by Arcellx Inc.