Amgen Inc said on Tuesday its potent new cholesterol fighter, Repatha, met the primary and secondary goals of a study designed to show it can decrease plaque buildup in heart arteries of patients already taking widely used statin drugs, such as Lipitor.

The biotechnology company, whose shares were up 1.6 percent, will present detailed data from the study at a major heart conference in November.

Repatha belongs to an expensive new class of injectable drugs that dramatically lower levels of "bad" LDL cholesterol. The new medicines have a list price of more than $14,000 a year. Regeneron Pharmaceuticals and Sanofi sell a rival drug called Praluent. They are far more expensive than statins, which are almost all now available in cheap generic versions.

Health insurers and other companies that negotiate prescription drug usage have been slow to cover the new medicines without evidence that they actually reduce heart attacks and deaths as statins do. Data from large studies expected to show that is expected next year.

"One year after the FDA approved Repatha, nearly two-thirds of patients prescribed Repatha are still being denied access," Amgen research chief Sean Harper said in a statement.

If the new drugs, known as PCSK9 inhibitors, can halt or significantly reverse atherosclerosis, that could be a strong indicator they will be able to reduce heart attack risk.

"Atherosclerosis is the major underlying cause of cardiovascular disease, which remains the leading cause of death worldwide," Harper said.

In the 78-week study of 968 heart patients already on optimum statin therapy, Repatha lowered the percentage of atheroma volume in coronary arteries and demonstrated some plaque regression.