Exhibit 4.1

SEE REVERSE FOR IMPORTANT NOTICE REGARDING OWNERSHIP AND TRANSFER RESTRICTIONS AND CERTAIN OTHER INFORMATION I INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE CUS I P 4 5 7 2 0 L 1 0 7 COMMON STOCK SEE REVERSE FOR CERTAIN DEFINITIONS FULLY PAID AND NON-ASSESSABLE SHARES OF THE PAR VALUE OF $0.0001 EACH OF THE COMMON STOCK OF Inhibrx, Inc. (hereinafter called the “Company”), transferable on the books of the Company in Person or by duly authorized attorney, upon surrender of this Certificate properly endorsed. This Certificate and the shares represented hereby, are issued and shall be held subject to all of the provisions of the Certificate of Incorporation, as amended, and the Bylaws, as amended, of the Company (copies of which are on file with the Company and with the Transfer Agent), to all of which each holder, by acceptance hereof, assents. This Certificate is not valid unless countersigned and registered by the Transfer Agent and Registrar. WITNESS the facsimile seal of the Company and the facsimile signatures of its duly authorized officers. HIBRX, IN I N C. 2017E DEL A R AW Secretary Chief Executive Officer President

The following abbreviations, when used in the inscription on the face of this certificate, shall be construed as though they were written out in full according to applicable laws or regulations: TEN COM - as tenants in common UNIF GIFT MIN ACT- Custodian TEN ENT -as tenants by the entireties (Cust) (Minor) IT TEN -as joint tenants with right of under Uniform Gifts to Minors survivorship and not as tenants A rt in common (State) TTEE - trustee under Agreement dated Additional abbreviations may also be used though not in the above list. For value received, hereby sell, assign and transfer unto PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS INCLUDING POSTAL ZIP CODE OF ASSIGNEE. Shares of the common stock represented by this certificate and do hereby irrevocably constitute and appoint attorney, to transfer the said stock on the books of the within-named corporation with full power of substitution in the premises. DATED NOTICE:The signature to this assignment must correspond with the name as written upon the face of the certificate in every particular without alteration or enlargement or any change whatsoever. SIGNATURE GUARANTEED: THE SIGNATURE(S) SHOULD BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION, (BANKS, STOCKBROKERS, SAVINGS AND LOAN ASSOCIATIONS AND CREDIT UNIONS WITH MEMBERSHIP IN AN APPROVED SIGNATURE GUARANTEE MEDALLION PROGRAM), PURSUANT TO S.E.C. RULE 17Ad-l5.