Exhibit 99.1 Xencor Reports Third Quarter 2025 Financial Results PASADENA, Calif.--Nov. 5, 2025-- Xencor, Inc. (NASDAQ:XNCR), a clinical-stage biopharmaceutical company developing engineered antibodies for the treatment of cancer and autoimmune diseases, today reported financial results for the third quarter ended September 30, 2025 and provided recent business and clinical program updates. "Xencor's two novel, first-in-class, CD3 T-cell engaging bispecific antibodies, XmAb819 and XmAb541, have demonstrated ...