Material Agreement (Form 8-K)

As previously disclosed, on April 27, 2026, XOMA Royalty Corporation, a Nevada corporation (the "Company" or "XOMA Royalty"), entered into an Agreement and Plan of Merger (the "Merger Agreement"), by and among the Company, Ligand Pharmaceuticals Incorporated, a Delaware corporation ("Parent"), and Flex Merger Sub, Inc., a Nevada corporation and wholly-owned subsidiary of Parent ("Merger Sub"), pursuant to which, and upon the terms and subject to the conditions thereof, including, without limitation, effecting the Holding Company Reorganization (as defined below), Merger Sub will merge with and into a newly formed Nevada corporation, XOMA Royalty Holdings Corporation ("HoldCo"), (the "Merger"), with HoldCo surviving the Merger as a wholly owned subsidiary of Parent. HoldCo is a wholly-owned subsidiary of XOMA Royalty and was formed for the sole purpose of effecting a holding company reorganization (the "Holding Company Reorganization") pursuant to Nevada Revised Statutes, as amended ("NRS"), 92A (or such other applicable provisions of the NRS).

On May 16, 2026, XOMA Royalty, Parent and the Merger Sub entered into Amendment No. 1 to the Agreement and Plan of Merger ("Amendment No. 1") which, among other things, adds HoldCo as a party to the Merger Agreement.

The foregoing description of Amendment No. 1 does not purport to be complete and is qualified in its entirety by reference to Amendment No. 1, a copy of which is attached hereto as Exhibit 2.1 and is incorporated herein by reference.

Additional Information and Where to Find It

In connection with the proposed acquisition, XOMA Royalty will be filing documents with the SEC, including preliminary and definitive proxy statements relating to the proposed acquisition. The definitive proxy statement will be mailed to XOMA Royalty's stockholders in connection with the proposed acquisition. This Current Report on Form 8-K is not a substitute for the proxy statement or any other document that may be filed by XOMA Royalty with the SEC. BEFORE MAKING ANY VOTING DECISION, INVESTORS AND SECURITY HOLDERS ARE URGED TO READ THE PRELIMINARY AND DEFINITIVE PROXY STATEMENTS AND ANY OTHER DOCUMENTS TO BE FILED WITH THE SEC IN CONNECTION WITH THE PROPOSED ACQUISITION OR INCORPORATED BY REFERENCE IN THE PROXY STATEMENT WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED ACQUISITION. Any vote in respect of resolutions to be proposed at XOMA Royalty's stockholder meeting to approve the proposed acquisition or other responses in relation to the proposed acquisition should be made only on the basis of the information contained in XOMA Royalty's proxy statement. Investors and security holders may obtain free copies of these documents (when they are available) and other related documents filed with the SEC at the SEC's web site at www.sec.gov, or at investors.xoma.com.

No Offer or Solicitation

This Current Report on Form 8-K is for information purposes only and is not intended to and does not constitute, or form part of, an offer, invitation or the solicitation of an offer or invitation to purchase, otherwise acquire, subscribe for, sell or otherwise dispose of any securities, or the solicitation of any vote or approval in any jurisdiction, pursuant to the proposed acquisition or otherwise, nor shall there be any sale, issuance or transfer of securities in any jurisdiction in contravention of applicable law.

Participants in the Solicitation

XOMA Royalty and its directors, executive officers and other members of management and employees, under SEC rules, may be deemed to be "participants" in the solicitation of proxies from stockholders of XOMA Royalty in favor of the proposed acquisition. Information about XOMA Royalty's directors and executive officers is set forth in XOMA Royalty's proxy statement for its 2026 annual meeting of stockholders, which was filed with the SEC on March 30, 2026. Additional information concerning the interests of XOMA Royalty's participants in the solicitation, which may, in some cases, be different than those of XOMA Royalty's stockholders generally, will be set forth in XOMA Royalty's proxy statement relating to the proposed acquisition when it becomes available. These documents are available free of charge at the SEC's web site at www.sec.gov and at investors.xoma.com.