Phase 1 Trial of XB371 Topoisomerase Inhibitor

This trial evaluates first-in-human TF–topoisomerase-I inhibitor ADC (XB371), in participants with locally advanced or metastatic solid tumors. Using dose-escalation cohorts and randomized expansion parts A and B, the study aims to determine safety, tolerability, and recommended dosing administered every 3 weeks. Eligible patients with advanced, recurrent, or metastatic tumors are assigned based on tumor type data. Conducted by Exelixis in San Antonio, the trial is a first-in-human investigation of XB371. Many solid tumors still rely on topo-I/II–based regimens (e.g., irinotecan, topotecan); this first-in-human scaffold seeks comparable activity with a cleaner hematologic/GI profile.