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Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
Checkbox not checked   Rule 13d-1(b)
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SCHEDULE 13D/A 0001214659-25-006873 0001232621 XXXXXXXX LIVE 1 Common Stock, par value $0.0001 per share 09/17/2025 false 0001888012 43157M102 HilleVax, Inc. 321 Harrison Avenue, Suite 500 Boston MA 02118 Kevin Tang 858-200-3830 4747 Executive Drive Suite 210 San Diego CA 92121 0001232621 N TANG CAPITAL MANAGEMENT, LLC WC N DE 0.00 0.00 0.00 0.00 0.00 N 0 OO 0001178579 N KEVIN TANG WC N X1 0.00 0.00 0.00 0.00 0.00 N 0 IN 0001191935 N TANG CAPITAL PARTNERS, LP WC N DE 0.00 0.00 0.00 0.00 0.00 N 0 PN 0002064011 N TANG CAPITAL PARTNERS INTERNATIONAL, LP WC N DE 0.00 0.00 0.00 0.00 0.00 N 0 PN 0002036763 N TANG CAPITAL PARTNERS III, INC WC N NV 0.00 0.00 0.00 0.00 0.00 N 0 CO 0002036770 N TANG CAPITAL PARTNERS IV, INC WC N NV 0.00 0.00 0.00 0.00 0.00 N 0 CO 0001970065 N CONCENTRA BIOSCIENCES, LLC WC N DE 0.00 0.00 0.00 0.00 0.00 N 0 OO Common Stock, par value $0.0001 per share HilleVax, Inc. 321 Harrison Avenue, Suite 500 Boston MA 02118 This Schedule 13D/A (this "Statement") amends the Schedule 13D (the "Original Schedule 13D") filed on May 2, 2025. Items 4 and 5 of the Statement are hereby amended and supplemented to the extent hereinafter expressly set forth. Except as amended hereby, the original disclosure set forth in the Statement shall remain unchanged. All capitalized terms used and not expressly defined herein have the respective meanings ascribed to such terms in the Original Schedule 13D. Item 4 of the Schedule 13D is amended by adding the following: Closing of the Merger: On September 17, 2025, the Issuer completed its merger with XOMA Royalty Corporation ("Parent") and Parent's wholly-owned subsidiary, XRA 4 Corp. ("Merger Sub") pursuant to the terms of the Merger Agreement, whereby Merger Sub merged with and into the Issuer, in accordance with the General Corporation Law of the State of Delaware, with the Issuer continuing as the surviving corporation and as a wholly owned subsidiary of Parent. Pursuant to the Merger Agreement, on September 17, 2025, each issued and outstanding share of the Issuer's Common Stock was cancelled. The information previously provided in response to Item 5 is hereby amended and restated by replacing the text thereof in its entirety with the following: The information set forth in the cover pages of this Schedule 13D is hereby incorporated by reference into this Item 5. As of the date hereof the Reporting Persons do not own any shares of the Issuer's Common Stock. See item 5(a) above. Except as described in this Amendment No. 1, there have been no transactions in the Issuer's Common Stock during the past 60 days by the Reporting Persons. No person other than a Reporting Person has the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, Common Stock beneficially owned by the Reporting Persons. The Reporting Persons ceased to be beneficial owners of 5% or more of the Issuer's Common Stock on September 17, 2025. TANG CAPITAL MANAGEMENT, LLC /s/ Kevin Tang Manager 09/19/2025 KEVIN TANG /s/ Kevin Tang Self 09/19/2025 TANG CAPITAL PARTNERS, LP /s/ Kevin Tang Manager, Tang Capital Management, LLC, General Partner 09/19/2025 TANG CAPITAL PARTNERS INTERNATIONAL, LP /s/ Kevin Tang Manager, Tang Capital Management, LLC, General Partner 09/19/2025 TANG CAPITAL PARTNERS III, INC /s/ Kevin Tang Chief Executive Officer 09/19/2025 TANG CAPITAL PARTNERS IV, INC /s/ Kevin Tang Chief Executive Officer 09/19/2025 CONCENTRA BIOSCIENCES, LLC /s/ Kevin Tang Chief Executive Officer 09/19/2025