Sanofi and partner Regeneron Pharmaceuticals has announced positive preliminary results from two Phase II studies in which patients with elevated low-density lipoprotein cholesterol were treated with the firms' new antibody.

The drug, REGN727/SAR236553 is a novel, high-affinity, subcutaneously administered, fully-human antibody targeting PCSK9 (proprotein convertase subtilisin/kexin type 9). Blocking the PCSK9 pathway is a novel mechanism for lowering LDL-C, Sanofi noted.

The trial studied patients with heterozygous familial hypercholesterolaemia with elevated cholesterol despite lipid-lowering therapy (statins with or without ezetemibe). Interim results showed that after 12 weeks of treatment, patients who received different dosing regimens of REGN727 achieved mean LDL-C reductions ranging from 30% to greater than 65%, compared to 10% with placebo. Patients in the study are being followed for 20 weeks.

Another Phase II trial studied patients with primary hypercholesterolaemia with elevated cholesterol who were on a stable low dose (10mg) of Pfizer's Lipitor (atorvastatin).  The primary objective of the study was to compare the effect of switching to a high dose of atorvastatin alone (80mg) versus a high dose of Lipitor combined with REGN727.

After eight weeks of treatment, patients who received REGN727 plus atorvastatin 80mg achieved a greater than 65% reduction in mean LDL-C compared to 17% for atorvastatin 80mg only.

A third study of this Phase II program is still ongoing, but Sanofi R&D chief Elias Zerhouni said the "preliminary results with our anti-PCSK9 antibody are very encouraging”. He added that the firm "remains committed to advancing this program into Phase III development as soon as possible".

George  Yancopoulos, chief scientific officer at Regeneron, said that "despite the availability of statins, elevated cholesterol and coronary artery disease remain a leading cause of morbidity and mortality" and the drug has "potential to offer a novel mechanism for lowering LDL-C in a broad range of patients".