Alnylam Pharmaceuticals last week released data from a phase I study of its siRNA-based hypercholesterolemia drug ALN-PCS, reporting that a single dose of the agent could significantly and durably lower both its target and low-density lipoprotein cholesterol levels.
In the study, 32 healthy volunteers with elevated LDL were enrolled into six sequential dose cohorts, ranging from 0.015 mg/kg to 0.4 mg/kg. Patients were randomized to receive either drug or placebo.
According to Alnylam, drug treatment led to “rapid, dose-dependent, and durable reductions in LDL-C of up to 50 percent relative to baseline and placebo, with a statistically significant mean reduction of 41 percent at the 0.4 mg/kg dose level.”
Additionally, treatment triggered an up to 84 percent reduction in plasma levels of the drug's target, proprotein convertase subtilisn/kexin type 9, with a mean reduction of 68 percent in the highest dose group. A dose-dependent decrease in the proportion of subjects achieving target levels of LDL-C was also observed.
“The effects of a single dose of ALN-PCS support a once-monthly dose administration regimen for future studies,” Alnylam said.
No serious adverse events related to ALN-PCS were observed, and there was no significant change compared to baseline in levels of high-density lipoprotein.
ALN-PCS comprises siRNAs that are delivered using the so-called MC3 lipid nanoparticle technology, to which both Alnylam and partner Tekmira Pharmaceuticals have laid claim (GSN 3/17/2011).
Earlier this year, after releasing positive preliminary phase I data, Alnylam said that it would not advance ALN-PCS into later-stage clinical testing without a partner (GSN 1/12/2012).