ProQR doses first participant in Phase 1 trial of AX-0811

ProQR Therapeutics N.V. said on September 9, 2026 that the first participant has been dosed in the Phase 1 clinical trial of AX-0811 in healthy volunteers.¹

AX-0811 is described as ProQR's next-generation, AI-discovered investigational RNA editing oligonucleotide (EON) aimed at NTCP, with preclinical data showing it is more potent and has a longer half-life than the earlier candidate AX-0810.¹ The company said AX-0811 is being developed as a potential disease-modifying treatment for cholestatic liver diseases, including biliary atresia.¹

According to ProQR, the Phase 1 study is meant to assess safety, tolerability, pharmacokinetics, and pharmacodynamic biomarkers of AX-0811 in healthy volunteers, and it draws on the company's prior clinical work with AX-0810.¹ ProQR said target engagement data from the first two dosing cohorts of the Phase 1 study are expected in early January 2027.¹

Separately, ProQR will host a virtual investor and analyst event titled "NTCP Modulation in Biliary Atresia via Liver-Targeted RNA Editing" on September 30, 2026 starting at 11am ET, featuring company management and Gideon Hirschfield, a professor of gastroenterology and hepatology at the Toronto Centre for Liver Disease.¹ The session is intended to review the role of bile acids and NTCP modulation in cholestatic liver disease, focusing on biliary atresia, and to cover recently reported AX-0810 Phase 1 target engagement data alongside the development strategy for the upcoming AX-0811 program.¹