Hoping to boost confidence in its Repatha cholesterol drug, Amgen said the treatment significantly reduced the risk of heart attacks, strokes, and death in patients with heart disease in a closely watched clinical trial. But the biotech did not disclose any data to demonstrate the extent to which the medicine reduced these cardiovascular risks. Complete details will not become available until an American College of Cardiology meeting next month. But by declaring now that Repatha met the primary endpoint in the study, Amgen hopes to persuade payers to provide greater coverage for the pricey medicine. About 75 percent of prescriptions have reportedly been rejected due to the $14,000 list price and the lack of cardiovascular outcomes data.