공시 • May 05
Xencor Inc Reports Final Results Of Phase 1 Study Of XmAb942 And Provides Update On XmAb412
Xencor, Inc. reported final results from the Phase 1 study of XmAb942, a novel, potential best-in-class, long-acting anti-TL1A antibody for the treatment of inflammatory bowel disease (IBD). The results are being presented at Digestive Disease Week® (DDW), being held in Chicago. The company will also present the preclinical characterization of XmAb412 (TL1A x IL23p19) during the conference and will host a webcast at 8:00 a.m. EDT (5:00 a.m. PDT) on Tuesday, May 5, to discuss both presentations. Enrollment into the global Phase 2b XENITH-UC study of XmAb942 remains on track, with expectations that support a blinded interim analysis around year-end 2026 and the full results of the primary endpoint analysis during the second half of 2027. The study is enrolling approximately 220 patients across three active treatment arms and one placebo arm using asymmetric randomization, and the primary endpoint is clinical remission defined by the modified Mayo score at week 12. Enrollment into a first-in-human dose-escalation study of XmAb412, a novel first-in-class bispecific antibody targeting TL1A and IL23p19, is expected to begin during the third quarter of 2026. The first-in-human study in healthy participants is designed to characterize the pharmacokinetics and pharmacodynamics of XmAb412 and support further development for the treatment of patients with autoimmune and inflammatory diseases in 2027. Final results of the Phase 1 study of XmAb942 in healthy participants support a potential best-in-class drug profile in the XENITH-UC study. The Phase 1 study was a randomized, double-blind, placebo-controlled, dose-escalation trial exploring intravenous (IV) and subcutaneous (SC) dose administration, at three escalating dose levels. The results reflect analyses with participants in single-dose cohorts (IV, n=24; SC, n=24) and in multiple-dose cohorts (IV, n=16). XmAb942 is projected to maintain higher drug exposure than first-generation TL1A antibodies during both induction and maintenance treatment. Quantitative pharmacology modeling based on integrated experimental and published data for XmAb942 and multiple first-generation TL1A antibodies supports population-level comparisons of pharmacokinetic (PK) and pharmacodynamic (PD) profiles across these compounds. Induction phase: XmAb942 provides markedly enhanced TL1A inhibition and is predicted to achieve greater than 99% TL1A inhibition in 86% of patients, compared to 31% and 40% for first-generation anti-TL1A antibodies. Maintenance phase: XmAb942 is designed to deliver maximal TL1A inhibition with a single subcutaneous injection every 12 weeks and is predicted to achieve greater than 90% TL1A inhibition in 90% of patients, compared to 60% and 68% for first-generation anti-TL1A antibodies, which are dosed every 4 weeks. All dose levels and routes of administration of treatment were well tolerated. Rates of overall treatment-emergent adverse events (TEAEs) were similar between XmAb942 (75%) and placebo (69%). No serious or severe TEAEs were observed, and no TEAEs led to discontinuation from the study. Headache was the most common TEAE and occurred in 33% of participants administered XmAb942 and 38% of participants administered placebo. One mild injection site reaction and one administration site bruise were the only definite treatment-related adverse events; both were mild and occurred in the highest subcutaneous dose cohort. Immunogenicity profile supports best-in-class drug exposure. At the high-dose IV induction and single SC maintenance dose levels being tested in the ongoing XENITH-UC Phase 2b study, 25% of healthy participants in the Phase 1 study tested positive for anti-drug antibodies (ADA), and 0% had neutralizing antibodies to XmAb942. Across all XmAb942 doses tested in the Phase 1 study, the incidence of ADA positivity was 57% in healthy participants. The incidence and magnitude of ADA decreased with increasing drug exposure. One of 47 (2%) healthy participants administered XmAb942 had neutralizing antibodies, with no observed impact on free soluble TL1A. No impacts of ADA on safety or tolerability or on the population PK model of XmAb942 were observed. PK profile supports the single subcutaneous injection 12-week dosing interval used during the maintenance treatment period in XENITH-UC. The pooled analysis of single dose cohorts produced an estimated terminal half-life of 74.1 days. XmAb412 is a novel, human native-like, effector-less bispecific antibody incorporating Xtend™ half-life extension technology that simultaneously blocks signaling stimulated by IL23 and TL1A. XmAb412 binds TL1A and IL23p19 with single-digit picomolar affinity for TL1A and sub-picomolar affinity for IL23. XmAb412’s 1+1 XenLock™ format avoids large immune complex formation of 2+2 formats. XmAb412 robustly suppresses both TL1A and IL23 inflammatory pathways. In cellular assays, XmAb412 demonstrated IC50 values comparable or superior to clinical-stage TL1A antagonist antibodies and approved IL23 antagonist antibodies. XmAb412 is predicted to have a human half-life between 60 and 70 days. In non-human primates, XmAb412 achieved a half-life exceeding 20 days, with similar target engagement to monospecific antibodies. XmAb412 supports high-concentration, low viscosity and citrate-free formulation suitable for subcutaneous dosing. Evaluation of XmAb412 in healthy participants is expected to begin in the third quarter of 2026. XmAb942 is a high-potency, extended half-life, investigational anti-TL1A antibody in clinical development for patients with inflammatory bowel disease (IBD), such as ulcerative colitis (UC) and Crohn’s disease (CD). The first generation of anti-TL1A antibodies, designed to block the interaction between the DR3 receptor and its ligand TL1A, have reduced disease activity in patients with UC and CD in multiple clinical studies. Results from a Phase 1 dose-escalation study in healthy participants indicate that XmAb942 is well tolerated.