Xencor(US:XNCR)2025-10-24 17:30XmAb819 Clinical Trial - Key Findings - The Phase 1 dose-escalation study of XmAb819 in ccRCC showed a manageable safety profile, with most CRS events being Grade 1/2 and occurring during priming [47, 51, 136] - Correct dose preparation resulted in 4% Grade 3 CRS (2/51), while dose preparation errors led to 28% Grade 3 CRS (5/18) [40, 136] - In the target dose range, correct dose preparation resulted in 6% Grade 3 CRS (1/18), while dose preparation errors led to 50% Grade 3 CRS (3/6) [40, 136] - XmAb819 demonstrated an objective response rate (ORR) of 25% (95% CI: 9-49) and a disease control rate (DCR) of 70% (95% CI: 46-88) in the efficacy-evaluable target dose range (N=20) [55, 89, 125] - The median number of prior regimens for patients in the XmAb819 study was 4 (range: 1-8), with 70% having received ≥3 prior regimens [35, 89, 119] XmAb819 Development & Market Opportunity - Xencor is planning to start a pivotal study of XmAb819 as monotherapy in advanced ccRCC in 2027 [79, 104] - The global RCC market is expected to reach approximately $12 billion by 2030 [80] - In the U S, there are approximately 60,000 new cases of ccRCC per year [84] XmAb541 Early Results - Early data from the Phase 1 dose escalation study of XmAb541 showed promising anti-tumor activity in advanced ovarian cancer, endometrial cancer, and germ cell tumors [4, 93, 97] - The total sales in 1H25 for ovarian cancer drugs were $338 million, and for endometrial cancer drugs were $196 million [100]