Supplemental Prospectus - Form 424B3

Filed Pursuant to Rule 424(b)(3)

Registration No. 333-280127

PROSPECTUS SUPPLEMENT NO. 2

To Prospectus dated June 18, 2024

INHIBRX BIOSCIENCES, INC.

2,449,921 shares of Common Stock

This prospectus supplement No. 2 supplements the prospectus dated June 18, 2024, or the Prospectus, relating to the proposed resale or other disposition from time to time of an aggregate of up to 2,449,921 shares of Inhibrx Biosciences, Inc., or the Company, common stock, $0.0001 par value per share, or Common Stock, including (i) 300,146 shares of Common Stock held by the selling stockholders who have registration rights pursuant to the Registration Rights Agreement, dated May 29, 2024, by and among the Company and the holders listed thereto, or the Registration Rights Agreement, (ii) 991,849 shares of Common Stock that are issuable upon the exercise of warrants to purchase shares of Common Stock at an exercise price of $0.0001 per share, subject to proportional adjustments in the event of stock splits or combinations or similar events, or the Warrants, held by the selling stockholders who have registration rights pursuant to the Registration Rights Agreement, and (iii) 1,157,926 shares of Common Stock currently held by Inhibrx, Inc., an indirect wholly-owned subsidiary of Sanofi S.A., or Sanofi. The shares of Common Stock and Warrants were issued in connection with the sale of Inhibrx, Inc.'s INBRX-101, which was completed on May 30, 2024, as described in the Prospectus.

The Company is not selling any securities under the Prospectus and will not receive any of the proceeds from the sale of securities by the selling stockholders, except that the Company may receive up to approximately $100 in aggregate gross proceeds from the exercise of the Warrants, if the Warrants are exercised for cash (and, as applicable, not on a cashless basis), based on the per share exercise price of the Warrants.

Our registration of the resale of the shares of Common Stock covered by the Prospectus does not mean that the selling stockholders will offer or sell all or any of the shares of Common Stock. The selling stockholders or their assignees or successors-in-interest may offer and sell the shares of Common Stock described in the Prospectus in a number of different ways and at varying prices. We provide more information about how a selling stockholder may sell its shares of Common Stock in the section entitled "Plan of Distribution" in the Prospectus. We will pay the expenses incurred in registering the securities covered by the Prospectus, including legal and accounting fees.

This prospectus supplement incorporates into the Prospectus the information contained in our attached current report on Form 8-K, which was filed with the Securities and Exchange Commission on November 4, 2024.

You should read this prospectus supplement in conjunction with the Prospectus, including any supplements and amendments thereto. This prospectus supplement is qualified by reference to the Prospectus except to the extent that the information in the prospectus supplement supersedes the information contained in the Prospectus. This prospectus supplement is not complete without, and may not be delivered or utilized except in connection with, the Prospectus, including any supplements and amendments thereto.

Our Common Stock is quoted on the Nasdaq Global Market under the symbol "INBX." On November 1, 2024, the last reported sale price of our Common Stock was $15.80 per share.

We are an "emerging growth company" as that term is used in the Jumpstart Our Business Startups Act of 2012, and, as such, we have elected to comply with certain reduced public company reporting requirements for the Prospectus and future filings with the Securities and Exchange Commission.

INVESTING IN OUR COMMON STOCK INVOLVES RISKS. SEE THE SECTION ENTITLED "RISK FACTORS" BEGINNING ON PAGE 10 OF THE PROSPECTUS AND IN THE OTHER DOCUMENTS THAT ARE INCORPORATED BY REFERENCE IN THE PROSPECTUS.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is November 4, 2024

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): November 4, 2024

INHIBRX BIOSCIENCES, INC.

(Exact name of registrant as specified in its charter)

Delaware	001-42031	99-0613523
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)

11025 N. Torrey Pines Road, Suite 140

La Jolla, CA 92037

(Address of Principal Executive Offices and Zip Code)

Registrant's telephone number, including area code: (858) 795-4220

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common Stock, par value $0.0001 per share	INBX	The Nasdaq Global Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 8.01 Other Events.

On November 4, 2024, Inhibrx Biosciences, Inc. ("Inhibrx" or the "Company") announced a legal victory in a trade secrets case brought by I-Mab Biopharma ("I-Mab") in the United States District Court for the District of Delaware. The jury found in favor of Inhibrx, rejecting all allegations of misappropriation before it. I-Mab had initiated the lawsuit on March 1, 2022, alleging that Inhibrx and its Chief Scientific Officer, Brendan Eckelman, Ph.D., improperly accessed and used proprietary information related to several of I-Mab's research projects during a prior arbitration proceeding involving I-Mab, for which Dr. Eckelman served as an expert witness. However, the jury found no basis for these claims in finding in favor of Inhibrx. Certain matters remain before the Court.

Forward Looking Statements

The Company cautions you that statements contained in this Current Report on Form 8-K regarding matters that are not historical facts are forward-looking statements. These statements are based on the Company's current beliefs and expectations. These forward-looking statements include, but are not limited to, statements regarding: the fact that certain matters remain before the Court. Actual results may differ from those set forth in this press release due to the risks and uncertainties inherent in the Company's business, including, without limitation, risks and uncertainties regarding: the potential for any appeals or further proceedings by the Court relating to the I-Mab lawsuit; and other risks described from time to time in the "Risk Factors" section of its filings with the U.S. Securities and Exchange Commission, including those described in its Registration Statement on Form 10, as amended (File No. 001-42031), its Registration Statement on Form S-1, as amended and supplemented from time to time (File No. 333-280127) and its Quarterly Reports on Form 10-Q, and supplemented from time to time by its Current Reports on Form 8-K as filed from time to time. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and the Company undertakes no obligation to update these statements to reflect events that occur or circumstances that exist after the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: November 4, 2024
INHIBRX BIOSCIENCES, INC.
By:	/s/ Kelly Deck
Name:	Kelly Deck
Title:	Chief Financial Officer