Common Stock, $0.0075 par value

XOMA Royalty Corp

2200 POWELL STREET, EMERYVILLE, CA, 94608

Item 5(a) is hereby amended and restated to read as follows: The aggregate percentage of Shares reported owned by each person named herein is based on 12,129,405 Shares outstanding as of April 23, 2026, which is the total number of Shares outstanding as reported in Exhibit 2.1 to the Issuer's Current Report on Form 8-K filed with the Securities and Exchange Commission on April 27, 2026. As of the date hereof, the Reporting Persons and the Partners Managed Accounts hold an aggregate of 5,003 shares of Series X Preferred Stock, convertible into an aggregate of 5,003,000 Shares. Each share of Series X Preferred Stock is convertible into 1,000 Shares. The Reporting Persons and the Partners Managed Accounts do not have the right to convert any portion of the Series X Preferred Stock held by them to the extent that, after giving effect to such conversion, they, together with their Attribution Parties (as defined in the Series X Preferred Stock Certificate of Designation of Preferences, Rights and Limitations), would beneficially own a number of Shares in excess of 19.99% of the number of Shares outstanding immediately after giving effect to the issuance of Shares pursuant to such conversion (the "Series X Beneficial Ownership Limitation"). As of the date hereof, the Series X Beneficial Ownership Limitation prohibits the conversion of all the Series X Preferred Stock held by the Reporting Persons and the Partners Managed Accounts. Pursuant to the Support Agreement, promptly following the date of the Support Agreement, the Reporting Persons shall (a) deliver a written notice to the Issuer to increase its Series X Beneficial Ownership Limitation to 45% pursuant to the terms of the Series X Preferred Stock, and (b) request in writing a waiver from the Issuer of the 61 day notice period and take all actions necessary to obtain such waiver. In addition, promptly following the execution of the Support Agreement, the Reporting Persons shall deliver to the Issuer a notice of conversion in the timeframe provided for in the Support Agreement providing for the conversion of all Series X Preferred Stock owned by the Reporting Persons. As of the date hereof, (i) BVF beneficially owned 1,322,758 Shares, excluding 2,313,000 Shares issuable upon the conversion of certain Series X Preferred Stock held by it, representing percentage ownership of approximately 10.9% of the Shares outstanding, (ii) BVF2 beneficially owned 1,267,545 Shares, excluding 1,506,000 Shares issuable upon the conversion of certain Series X Preferred Stock held by it, representing percentage ownership of approximately 10.5% of the Shares outstanding, (iii) Trading Fund OS beneficially owned 0 Shares, excluding 412,000 Shares issuable upon the conversion of certain Series X Preferred Stock held by it, representing percentage ownership of 0% of the Shares outstanding, and (iv) 0 Shares were held in the Partners Managed Accounts, excluding 772,000 Shares issuable upon the conversion of certain Series X Preferred Stock held in the Partners Managed Accounts, representing percentage ownership of 0% of the Shares outstanding. BVF GP, as the general partner of BVF, may be deemed to beneficially own the 1,322,758 Shares beneficially owned by BVF, representing percentage ownership of approximately 10.9% of the Shares outstanding. BVF2 GP, as the general partner of BVF2, may be deemed to beneficially own the 1,267,545 Shares beneficially owned by BVF2, representing percentage ownership of approximately 10.5% of the Shares outstanding. Partners OS, as the general partner of Trading Fund OS, may be deemed to beneficially own 0 Shares, representing percentage ownership of 0% of the Shares outstanding. BVF GPH, as the sole member of each of BVF GP and BVF2 GP, may be deemed to beneficially own the 2,590,303 Shares beneficially owned in the aggregate by BVF and BVF2, representing percentage ownership of approximately 21.4% of the Shares outstanding. Partners, as the investment manager of BVF and BVF2, may be deemed to beneficially own the 2,590,303 Shares beneficially owned in the aggregate by BVF and BVF2, representing percentage ownership of approximately 21.4% of the Shares outstanding. BVF Inc., as the general partner of Partners, may be deemed to beneficially own the 2,590,303 Shares beneficially owned by Partners, representing percentage ownership of approximately 21.4% of the Shares outstanding. Mr. Lampert, as a director and officer of BVF Inc. may be deemed to beneficially own the 2,590,303 Shares beneficially owned by BVF Inc., representing percentage ownership of approximately 21.4% of the Shares outstanding.

Item 5(c) is hereby amended to add the following: The Reporting Persons have not transacted in the securities of the Issuer during the past sixty days.