DaRui Bio Announces Positive Phase 1 Results for Novel siRNA Therapy RN0191 Targeting PCSK9

This Phase I study is a randomized, single-dose escalation, placebo-controlled trial designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics in healthy subjects with elevated LDL-C levels. The trial subjects are aged between 18 and 60 years, with a Body Mass Index (BMI) ranging from 19 to 30 kg/m². The data cutoff date was October 14, 2024. A total of 32 subjects were randomly assigned to receive treatments of 60mg, 200mg, 400mg, and 600mg. The average baseline LDL-C level was between 110-130 mg/dL.

After a single subcutaneous injection, RN0191 demonstrated good safety, with no serious adverse events reported. Only mild and transient adverse events were reported across all dose groups. Meanwhile, dose-dependent, significant, and sustained changes in PCSK9, LDL-C, and other lipid parameters were observed (see table below). Among them,

♦ Achieved an average maximum reduction of over 85% in PCSK9 and over 55% in LDL-C; on Day 180, the reduction in LDL-C remained as high as 42%, supporting the subsequent development of a twice-yearly dosing regimen for RN0191.

♦ Significant reductions in ApoB, Lp(a), non-HDL-C, and total cholesterol levels

♦ The reduction effects of PCSK9, LDL-C, and other lipid parameters mentioned above can be sustained for up to 6 months (until the end of the trial follow-up).