Exhibit 99.1 XOMA Reports Fourth Quarter and Full Year 2023 Financial Results and Highlights Recent and Upcoming Events Expected to Drive Shareholder Value Raised up to $140 million of non-dilutive non-recourse capital through a royalty-backed loan related to VABYSMO® from funds managed by Blue Owl Capital Received$15.5 million in cash payments related to our growing royalty base and the achievement of certain development milestones during 2023 Added third commercial asset to XOMA’s portfolio with the acqu ...