X0609 4 2026-10-14 0 0002007919 Inhibrx Biosciences, Inc. INBX 0001366074 Lappe Mark false C/O INHIBRX BIOSCIENCES, INC. 11025 NORTH TORREY PINES ROAD, SUITE 140 LA JOLLA CA 92037 1 1 0 0 Chief Executive Officer 0 Common Stock 2026-10-14 4 P 0 2470 84.0707 A 743018 I By the Lappe Family Trust Common Stock 2026-10-14 4 P 0 2470 84.9992 A 745488 I By the Lappe Family Trust Common Stock 2026-10-14 4 P 0 100 85.76 A 745588 I By the Lappe Family Trust Common Stock 2026-10-14 4 P 0 2449 84.0707 A 167449 I By Lappe Descendants' Trust Common Stock 2026-10-14 4 P 0 2451 84.9992 A 169900 I By Lappe Descendants' Trust Common Stock 2026-10-14 4 P 0 100 85.76 A 170000 I By Lappe Descendants' Trust Common Stock 54865 I The Mark Paul Lappe Roth IRA The shares were purchased in multiple transactions at prices ranging from $83.61 to $84.59 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. These securities are directly owned by the Lappe Family Trust. Mark P. Lappe is a trustee of the Lappe Family Trust and, in such capacity, may be deemed to indirectly beneficially own the securities owned by the Lappe Family Trust. The shares were purchased in multiple transactions at prices ranging from $84.65 to $85.62 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. These securities are directly owned by a trust, for the benefit of the reporting person's immediate family. Mark P. Lappe, as an immediate family member of the beneficiaries of the trust, may be deemed to indirectly beneficially own the securities owned by the trust. /s/ Kelly D. Deck, as attorney-in-fact for Mark P. Lappe 2026-10-14