Form 4 Filing for Mark Lappe

Mark Lappe, Chief Executive Officer and Director of Inhibrx Biosciences, Inc., reported several transactions of the company's common stock between September 25, 2026, and September 28, 2026. Lappe acquired shares through various trusts, including the Lappe Descendants' Trust and the Mark Paul Lappe Roth IRA. The transactions involved the purchase of common stock, with prices ranging from $98.27 to $101.80 per share. Specifically, on September 25, 2026, Lappe acquired 3,324 shares at a weighted-average price of $98.8659 and 2,176 shares at a weighted-average price of $99.5988, both acquired through the Lappe Family Trust. On September 28, 2026, further acquisitions were made through the Lappe Family Trust, including 1,500 shares at a weighted-average price of $98.8803 and 3,000 shares at a weighted-average price of $101.702. Following these transactions, the total number of shares held by Lappe and associated trusts increased. Footnotes indicate that Lappe, as a trustee or beneficiary, may be deemed to indirectly beneficially own these securities. He has undertaken to provide detailed information on share numbers and prices upon request.