Preliminary results for Sanofi and Regeneron anti-PCSK9 antibody show dramatic decrease in 'bad' cholesterol

French drug major Sanofi (Euronext: SAN) and USA-based Regeneron (Nasdaq: REGN) have reported positive preliminary results from the Phase II study of their anti-PCSK9 antibody, REGN727/SAR236553 in hypercholesterolemia patients. Those who received REGN727 saw their low-density lipoprotein, or “bad cholesterol,” drop 65%, compared to just 17% of those who received an increased dose of Pfizer’s blockbuster Lipitor (atorvastatin).

One Phase II trial studied patients with heterozygous familial hypercholesterolemia (heFH) with elevated cholesterol (LDL-C>/=100mg/dL) despite lipid lowering therapy (statins with or without ezetemibe). The objective of the study was to compare the effect of adding REGN727/ SAR236553 to the existing lipid lowering therapy in heFH patients. In the primary efficacy analysis of the study, after 12 weeks of treatment, patients who received different dosing regimens of REGN727/SAR236553 achieved mean LDL-C reductions from baseline ranging from approximately 30% to greater than 65% depending on the dosing regimen of REGN727/SAR236553 compared to a mean reduction of 10% with placebo (p<0.05 for all dose groups). Patients in the study are being followed for a total of 20 weeks for safety.

In this trial, REGN727/SAR236553 was generally well tolerated over 12 weeks. There were no elevations in LFTs >3 times the upper limit of normal (ULN) and no cases of elevated CPK reported. The most common adverse event was injection site reaction. There were no serious adverse events on active treatment. Full safety data from the eight-week post-treatment monitoring period will be presented at a future medical congress upon final analysis.