SCHEDULE 13D/A

Arcellx Inc

Common Stock $0.001 par value per share · CUSIP: 03940C100

Event date: 2025-08-12

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• New Enterprise Associates 15, L.P.Reported CIK 0001629794

  Shares: 3,045,262.00 · Class: 5.49%

• NEA Partners 15, L.P.Reported CIK 0001640031

  Shares: 3,045,262.00 · Class: 5.49%

• NEA 15 GP, LLCReported CIK 0001640033

  Shares: 3,045,262.00 · Class: 5.49%

• Forest BaskettReported CIK 0001277631

  Shares: 3,045,262.00 · Class: 5.49%

• Anthony A. Florence, Jr.Reported CIK 0001559827

  Shares: 3,045,262.00 · Class: 5.49%

• Mohamad H. MakhzoumiReported CIK 0001630226

  Shares: 3,045,262.00 · Class: 5.49%

• Scott D. SandellReported CIK 0001237289

  Shares: 3,055,360.00 · Class: 5.51%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.