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 14^th day of August, 2025.

NEW ENTERPRISE ASSOCIATES 15, L.P.

  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:                             *                                

 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.