AX-0810

June 25, 2026: ProQR Therapeutics N.V. (NASDAQ: PRQR) reported positive target-engagement biomarker data from its ongoing multiple ascending dose Phase 1 study of AX-0810, a subcutaneous GalNAc-conjugated Axiomer RNA editing oligonucleotide designed to modulate NTCP for cholestatic liver diseases including biliary atresia. In 22 evaluable healthy volunteers from the 3 mg/kg and 6 mg/kg cohorts, AX-0810 showed dose-dependent NTCP engagement across three predefined biomarker measures, including up to an 8-fold increase in total serum bile acids (exceeding the company’s 2-fold threshold), with concordant changes in bile acid profile and circulating TUDCA following an oral TUDCA challenge. The company also reported statistically significant, dose-dependent increases in urinary excretion of conjugated bile acids and no changes in hormone levels. Safety/tolerability were favorable with no serious adverse events or pruritus; PK to date suggests sustained engagement with an ~8-week half-life.

Upcoming milestones: 9 mg/kg cohort data and 12-week follow-up from Phase 1 by year-end 2026; full Phase 1 data presentation later in 2026. AX-0811 (next-generation NTCP EON) CTA submission targeted mid-2026 and initial healthy-volunteer data by year-end 2026; pediatric biliary atresia IIT in China initial data in 1H 2027; potential Phase 2 start mid-2027 with interim analysis by mid-2028. Other pipeline: AX-0422 (MPS1/Hurler, IDUA) CTA early 2027 with initial data 1H 2027; AX-2911 (PNPLA3) FIH IIT in China in 1H 2027.