Dec 19 (Reuters) - Amgen Inc said its closely watched experimental cholesterol drug succeeded in reducing the level of bad cholesterol in the blood, compared to a placebo, in a late-stage trial.

The data was consistent with the results from a large mid-stage trial that showed the drug, evolocumab, lowered LDL cholesterol by 52 percent after one year of treatment.

Evolocumab belongs to class of drugs called PCSK9 inhibitors, which work by blocking a protein that prevents the liver from removing LDL cholesterol from blood.

The late-stage trial, called Descartes, tested the drug in 901 patients with high levels of bad cholesterol and a range of heart risks.