X0609 4 2026-09-08 0 0002007919 Inhibrx Biosciences, Inc. INBX 0001240801 FORSYTH DOUGLAS false C/O INHIBRX BIOSCIENCES, INC. 11025 NORTH TORREY PINES ROAD, SUITE 140 LA JOLLA CA 92037 1 0 0 0 0 Common Stock 2026-09-08 4 P 0 2500 114.6469 A 227064 I By the Forsyth Family Trust Dated July 20, 2001 The shares were purchased in multiple transactions at prices ranging from $114.36 to $114.689 inclusive. The reported price reflects the weighted-average purchase price. The reporting person hereby undertakes to provide upon request to the Securities and Exchange Commission staff, the Issuer or a security holder of the Issuer full information regarding the number of shares and prices at which the transactions were effected. The reporting person is a trustee of the Forsyth Family Trust Dated July 20, 2001 and, in such capacity, may be deemed to indirectly beneficially own the securities owned by the Forsyth Family Trust Dated July 20, 2001. /s/ Kelly D. Deck, as attorney-in-fact for Douglas G. Forsyth 2026-09-08