Sanofi and Regeneron Pharmaceuticals have developed an experimental drug that can reduce the number of heart attacks and strokes of patients by 50 percent by decreasing the amount of bad cholesterol in the body.

There are currently nine ongoing trials to test the efficiency of the drug called alirocumab. The researchers presented in the recent meeting of the European Society of Cardiology in Barcelona that four of them showed that the drug actually reduced the amount of low-density lipoprotein (LDL), or bad cholesterol, in their subjects.

The analysis from these studies also revealed that patients who were given the cholesterol drug became less prone to stroke, heart attacks and other cardiovascular events.

The ongoing clinical trial for the drug involved 2,341 patients. They were divided into two groups: one received conventional anti-cholesterol medication and alirocumab, while the other group was given the usual medicine plus placebo. The results of the study showed that only 1.4 percent the first group displayed symptoms of cardiovascular diseases, compared to 3 percent from the placebo group.

"To have this result emerge so quickly in this study is very encouraging," Jennifer Robinson, a cardiologist at the University of Iowa and leader of the study, told Reuters.

In addition, all four trials showed that the drug reduced the amount of bad cholesterol by up to 60 percent after 24 weeks. The only side effects noted were upper respiratory tract infections and stuffy nose.

Doctors are monitoring whether the drastic cut of LDL may have adverse effects on the body. However, current data showed no signs of such possibility. All the trials are expected to be completed by early 2015.

Sanofi and Regeneron refused to comment when asked about the price of the drug, but Barclays analysts estimated that a therapy using this drug may cost $6,000 per year.