Director Jon Faiz Kayyem filed a Form 4 with the SEC on September 23, 2026, disclosing a purchase of 5,000 shares of Inhibrx Biosciences, Inc. common stock at $100 per share.

Key Highlights

  • Transaction: Jon Faiz Kayyem, a director of Inhibrx Biosciences, acquired 5,000 shares of common stock on September 23, 2026.
  • Price paid: The shares were purchased at $100 each, per the filing.
  • Holding vehicle: The purchased shares are held indirectly by The Jon F. Kayyem and Paige Gates-Kayyem Family Trust, bringing that trust's total to 434,360 shares.
  • Additional indirect holdings: The filing also lists 250,000 shares held by the Jon Faiz Kayyem Revocable Trust, 250,000 shares by the Paige-Gates Kayyem Revocable Trust, and 69,843 shares each in custodial accounts for two minor children.
  • Disclaimer: Kayyem disclaims beneficial ownership of shares held in the family trust and the children's custodial accounts, except to the extent of any indirect pecuniary interest in his distributive shares therein.

Kayyem's Purchase and Indirect Ownership Structure at Inhibrx Biosciences

According to the Form 4 filed with the SEC, Jon Faiz Kayyem, identified as a director of Inhibrx Biosciences, Inc. (NASDAQ:INBX), executed a purchase transaction coded "P" on September 23, 2026. The filing reports that 5,000 shares of common stock were acquired at a price of $100 per share. These shares are held indirectly through The Jon F. Kayyem and Paige Gates-Kayyem Family Trust, of which Kayyem serves as trustee. Following the transaction, the trust holds 434,360 shares of common stock, per the filing.

The filing also discloses several other indirect holdings attributed to Kayyem. The Jon Faiz Kayyem Revocable Trust, for which he is trustee, holds 250,000 shares. The Paige-Gates Kayyem Revocable Trust, for which Kayyem's spouse is trustee, also holds 250,000 shares. In addition, the filing notes 69,843 shares each in two separate custodial accounts managed by Kayyem for the benefit of two minor children, identified as Child A and Child B.

The filing notes that Kayyem disclaims beneficial ownership of securities held in the family trust and the two children's custodial accounts, "except to the extent of any indirect pecuniary interest in his distributive shares therein." No derivative securities transactions were reported. The form was signed by Kelly Deck as attorney-in-fact to Jon Faiz Kayyem on September 23, 2026.

What Was Disclosed

This Form 4 reports a September 23, 2026 open-market purchase of 5,000 shares of Inhibrx Biosciences common stock at $100 per share by director Jon Faiz Kayyem, held indirectly through a family trust, along with a summary of his other indirect beneficial ownership positions.