XYone Therapeutics, a Canton, Massachusetts-based clinical-stage biotechnology company, dosed the first patient in a Phase 1b/2 trial of XYA02 (AT2021), its antibody–drug conjugate (ADC) targeting MUC1-C in advanced, relapsed and/or refractory solid tumors.
The FDA has granted XYA02 Orphan Drug Designation for both pancreatic cancer and gastric cancer, with additional applications pending, according to XYone.
XYA02 targets MUC1-C, the tumor-anchored C-terminal subunit of MUC1. XYone's chief scientific officer said MUC1-C remains tumor anchored — unlike the shed extracellular MUC1-N domain, whose heterogeneous glycosylation complicates targeting — and that this rationale supports an improved therapeutic index for an MUC1-C–directed ADC carrying an exatecan payload.
The Phase 1b/2 multicenter, open-label study (NCT07670312) will characterize safety, tolerability, and pharmacokinetics at escalating doses before expanding into selected tumor types based on emerging safety, biomarker, and antitumor activity data. The study includes patients with non-small cell lung, ovarian, gastric/gastroesophageal junction, and colorectal cancers. As a first-in-human dose-escalation study, no efficacy or safety data have yet been disclosed.