Xencor — October 26, 2026 Earnings Summary

XmAb819, an ENPP3 x CD3 bispecific antibody utilizing the XmAb 2+1 format, demonstrated meaningful antitumor activity in patients with advanced clear cell renal cell carcinoma (ccRCC) who had previously received immune checkpoint inhibitors and VEGFR-TKIs. In dose expansion cohorts, the confirmed objective response rates were 30% at 100 μg/kg, 44% at 200 μg/kg, and 45% at 400 μg/kg, with a disease control rate exceeding 80% in the 400 μg/kg cohort. The safety profile was manageable, characterized primarily by low-grade cytokine release syndrome and transient transaminase elevations during the priming phase, with no treatment-related deaths. Based on these efficacy and safety data, 400 μg/kg has been identified as the recommended Phase 3 dose, supporting plans to initiate a registration-enabling study in 2027.