Jon Faiz Kayyem - 16 Sep 2026 Form 4 Insider Report for Inhibrx Biosciences, Inc. (INBX)

Reporting relationship: Director
Issuer ticker: INBX
Reported as of: 16 Sep 2026
Net transaction value: +$500,000
SEC form: 4
Accepted by SEC: 17 Sep 2026, 17:46:50 UTC
Prior SEC filing: 08 Sep 2026
Source filing: View source filing
Reporting owner signature: /s/ Kelly Deck, as attorney-in-fact to Jon Faiz Kayyem

Key filing fact

Jon Faiz Kayyem filed Form 4 for Inhibrx Biosciences, Inc. (INBX) on 17 Sep 2026.

Key facts

This page summarizes Jon Faiz Kayyem's Form 4 filing for Inhibrx Biosciences, Inc. (INBX).
1 reported transaction and 0 derivative rows are listed below.
Accepted by SEC: 17 Sep 2026, 17:46.

Change

Previous filing in this sequence was filed on 08 Sep 2026.
Current net transaction value: +$500,000.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001366268 Primary reporting owner

Kayyem Jon Faiz

Relationship: Director
Address: C/O INHIBRX BIOSCIENCES, INC., 11025 NORTH TORREY PINES ROAD, SUITE 140, LA JOLLA
Signature: /s/ Kelly Deck, as attorney-in-fact to Jon Faiz Kayyem
Signature date: 17 Sep 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

INBX transaction

Common Stock

Purchase

Transaction value: $500,000
Shares: +5,000
Change %: +1.2%
Price: $100.00
Shares after: 429,360
Date: 16 Sep 2026
Ownership: By The Jon F. Kayyem and Paige Gates-Kayyem Family Trust
Footnotes: F1

INBX holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 250,000
Date: 16 Sep 2026
Ownership: By Jon Faiz Kayyem Revocable Trust
Footnotes: F2

INBX holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 250,000
Date: 16 Sep 2026
Ownership: By Paige Gates-Kayyem Revocable Trust
Footnotes: F3

INBX holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 69,843
Date: 16 Sep 2026
Ownership: By Child A
Footnotes: F4

INBX holding

Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 69,843
Date: 16 Sep 2026
Ownership: By Child B
Footnotes: F5

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 5 footnotes

Footnote F1

These securities are directly owned by The Jon F. Kayyem and Paige Gates-Kayyem Family Trust. Jon Faiz Kayyem is the trustee of The Jon Faiz Kayyem and Paige N. Gates Family Trust and he disclaims beneficial ownership of these securities, except to the extent of any indirect pecuniary interest in his distributive shares therein.

Footnote F2

These securities are directly owned by the Jon Faiz Kayyem Revocable Trust, of which Jon Faiz Kayyem is the trustee.

Footnote F3

These securities are directly owned by the Paige-Gates Kayyem Revocable Trust, of which Jon Faiz Kayyem's spouse is the trustee.

Footnote F4

These securities are directly owned by a custodial account managed by the reporting person for the benefit of the reporting person's minor child, Child A. The reporting person disclaims beneficial ownership of these securities, except to the extent of any indirect pecuniary interest in his distributive shares therein.

Footnote F5

These securities are directly owned by a custodial account managed by the reporting person for the benefit of the reporting person's minor child, Child B. The reporting person disclaims beneficial ownership of these securities, except to the extent of any indirect pecuniary interest in his distributive shares therein.