Xencor is a clinical-stage biopharmaceutical company that engineers antibody drug candidates for cancer and autoimmune diseases. Xencor's core scientific asset is its XmAb technology platform, a suite of proprietary tools for engineering the Fc domain — the structural backbone of antibodies — to create molecules with enhanced or novel properties, including bispecific binding, extended half-life, enhanced immune cell recruitment, and selective immune suppression. Xencor's most important proprietary format is the XmAb 2+1 bispecific, which binds two tumor antigen targets and one T-cell receptor, designed to improve selectivity for cancer cells over normal tissue. Xencor has no approved products of its own; revenue comes from royalties on partner drugs that use its technology and from licensing fees and milestones. The most significant current revenue source is a royalty on Ultomiris, Alexion's marketed complement inhibitor, which uses Xencor's Xtend half-life Fc domain. Xencor also earns smaller royalties on Monjuvi, a marketed lymphoma antibody from Incyte. Beyond marketed products, several partnered programs are in late-stage development, including Amgen's xaluritamig in Phase 3 for prostate cancer and Zenas BioPharma's obexelimab for autoimmune disease, with a BLA filing expected in 2026. Xencor's wholly-owned pipeline includes five clinical-stage programs in oncology and autoimmune disease. Xencor outsources manufacturing and clinical operations, keeping its cost structure focused on R&D.