Based on positive results of Vytorin (ezetimibe/simvastatin) in patients with chronic kidney disease (CKD), Merck said it will apply for use of the cholesterol-lowering drug in this population.

The results, reported over the weekend, come from a 9,000 patient study called Sharp, in which Vytorin reduced the incidence of heart attack, stroke, stent procedure or death from cardiac causes by 16.1% compared to placebo. Cancer risk was equivalent to placebo. It’s the first trial to show that a statin confers cardiovascular benefits in CKD, which results in a progressive loss of kidney function.

Vytorin prescriptions have fallen significantly since 2008 when Merck released findings of a trial which found that ezetimibe, one-half of Vytorin and also the key ingredient in Merck’s Zetia, did nothing to enhance the artery-clearing benefits of simvastatin.

An indication for CKD, though, “may provide an inflection point for growth in the high potency statins,” wrote Credit Suisse analyst Catherine Arnold in an investor note. This group includes Vytorin, AstreZeneca’s Crestor and Pfizer’s Lipitor. None have been shown to provide benefit in CKD.

Arnold, citing data from the Verispan Physician Drug and Diagnosis audit, pointed out that there are about 10 million US patients with stage 3 CKD or worse, only 3% of whom are also diagnosed with hyperlipidemia, “so we suspect very little statin prescribing exists today.”

While it would be a victory for Vytorin, getting CKD on-label is not likely to change much in the way of sales, wrote Bernstein Research’s Tim Anderson: “Vytorin has lost too much ground already to competing brands (like Crestor) and about a year from now a whole new challenge will emerge in the form of Lipitor generics in the US.” His Vytorin sales projection remains unchanged at $1.96 billion in 2010 (4% of total Merck sales), declining to $1.39 billion in 2015 (3% of total Merck sales).

Sharp, which demonstrates Vytorin’s LDL-lowering benefit vs. placebo, may also provide some comfort that Improve-IT, a head-to-head trial comparing Vytorin to Zocor (simvastatin), will turn out to be flattering to Vytorin. That trial should report out in 2013.