EXHIBIT 1

AGREEMENT

Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, the undersigned hereby agree that only one statement containing the information required by Schedule 13D need be filed with respect to the ownership by each of the undersigned of shares of stock of Arcellx, Inc.

EXECUTED this 24^th day of February, 2026.

NEW ENTERPRISE ASSOCIATES 15, L.P.

By:

NEA PARTNERS 15, L.P.

General Partner

By:

NEA 15 GP, LLC

General Partner

By:                     *

Anthony A. Florence, Jr.

Managing Partner and Co-Chief Executive Officer

By:                     *

Mohamad Makhzoumi

Managing Partner and Co-Chief Executive Officer

NEA PARTNERS 15, L.P.

By:

NEA 15 GP, LLC
General Partner

  By:                     *

 Anthony A. Florence, Jr.

 Managing Partner and Co-Chief Executive Officer

  By:                     *

 Mohamad Makhzoumi

 Managing Partner and Co-Chief Executive Officer

NEA 15 GP, LLC

By:                     *

Anthony A. Florence, Jr.

Managing Partner and Co-Chief Executive Officer

By:                     *

Mohamad Makhzoumi

Managing Partner and Co-Chief Executive Officer

Forest Baskett

Anthony A. Florence, Jr.

Mohamad H. Makhzoumi

Scott D. Sandell

*/s/ Zachary Bambach

Zachary Bambach

As attorney-in-fact

This Agreement relating 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 hereto as Exhibit 2.

Arcellx, Inc. SCHEDULE 13D/A