Sanofi US and Regeneron Pharmaceuticals have reported positive results from the first Phase II trial of alirocumab, an investigational monoclonal antibody targeting PCSK9 (proprotein convertase subtilisin/kexin type 9), for the treatment of patients with low-density lipoprotein-cholesterol (LDL-C).

The results showed that the mean LDL-C percentage reduction from baseline to week 12, the primary efficacy endpoint, was significantly greater in patients randomised to receive one of three doses of alirocumab administered every other week (Q2W) 150mg, 75mg, and 50mg, in combination with statin therapy, compared with patients receiving placebo.

At week 12, the mean percentage reduction in LDL-C from baseline in patients receiving dosage of alirocumab 50mg, 75mg and 150mg was 55%, 62% and 72% respectively, compared to 3% in the placebo group.

The company said that all patients in each of the alirocumab groups achieved LDL-C levels of <100 mg/dL, compared to 8% of patients in the placebo group.

"The results from this trial support the efficacy and safety of alirocumab at a range of doses in Japanese patients."

Treatment emergent adverse events (TEAEs) in the trial were reported by 52% of patients in the alirocumab 50mg group, 48% of patients in the 75mg group, 64% of patients in the 150mg group, compared with 32% in the placebo group.

Most frequently reported TEAEs were nasopharyngitis, injection site reaction, back pain, cystitis and ligament sprain.

Sanofi Group head of the PCSK9 development and launch unit Jay Edelberg said: "Not only was alirocumab shown, in this study, to significantly reduce LDL-C in this patient population, the results of this study also demonstrate the potential efficacy of alirocumab at a range of doses."

The multicentre, placebo-controlled Phase II trial randomised about 100 patients with LDL-C greater than or equal to 100mg/dL receiving lipid-modifying therapy.

Regeneron chief scientific officer and Regeneron Laboratories president George Yancopoulos said hypercholesterolemia is a growing problem in Japan and many patients are poorly-controlled on statins.

"The results from this trial support the efficacy and safety of alirocumab at a range of doses in Japanese patients," Yancopoulos said.

According to the company, PCSK9 is said to be a determinant of circulating LDL levels, as it binds to LDL receptors resulting in their degradation so that fewer are available on liver cells to remove excess LDL-C from the blood.

Alirocumab is an investigational, fully-human monoclonal antibody discovered by Regeneron Pharmaceuticals and is currently being co-developed by Regeneron and Sanofi.