Rona Therapeutics unveiled promising early-stage findings for its PCSK9-targeted siRNA therapy, dubbed RN0191, at the American Heart Association's (AHA) annual scientific sessions on Sunday, demonstrating notable reductions in PCSK9 and low-density lipoprotein cholesterol (LDL-C) after a single dose. The Shanghai-based biotech gained the asset securing exclusive global rights to Sanofi’s siRNA platform in 2022. Touting 'best-in-class' prospects, Rona CEO Stella Shi, said the “results highlight RN0191's potential as a transformative siRNA therapy for global patients with elevated LDL-C…either as single agent therapy or as combinatory backbone to improve cardiovascular outcome."The Phase I study randomised 32 healthy participants aged 18 to 60, to receive a single dose of RN0191 in the range of 60 mg to 600 mg or placebo. Results showed that the RN0191 group achieved up to 95% maximum reduction in PCSK9 and a 74% drop in LDL-C, with average reductions of 87% and 56%, respectively, compared with placebo. Moreover, RN0191 maintained up to 42% LDL-C reduction at six months, indicating suitability for bi-annual dosing. Additionally, RN0191 demonstrated significant reductions in ApoB, Lipoprotein(a), non-high-density lipoprotein cholesterol and total cholesterol. In terms of safety, the therapy had no serious adverse events, with only mild and short-term side effects reported at all doses.Following a $33-million Series A round in 2022, Rona secured another $35 million this year to advance RN0191 and another lipid-lowering siRNA against APOC3, named RN0361, into mid-stage testing. Besides dyslipidaemia, the company’s pipeline features a range of liver-directed siRNA therapies being developed for obesity, metabolic dysfunction-associated steatohepatitis, atherosclerotic cardiovascular disease, IgA nephropathy and hypertension.