Merck's Zetia results inflame debate over statin prescribing

How low should LDL go? That is the debate that continues among heart doctors since the American Heart Association (AHA) upended statin prescribing guidelines last year, and Merck's ($MRK) Zetia is now caught in the middle.

Results of a study released Monday show that heart attack and stroke risks were reduced when patients took Zetia with a statin and got their LDL, so-called bad cholesterol, to about 53 from 70, the target under the old guidelines.

And as Reuters reports, that was all the proof that was needed by a large swath of doctors who have been put off by the new guidelines, which are based on a patient's medical history and lifestyle rather than a specific level of bad cholesterol.

Dr. Andrew Klaus

Like some others, Dr. Andrew Klaus of Mount Carmel Health System in Columbus, OH, told Reuters the Zetia trial is proof that for LDL, lower is better. "I never really bought the new guidelines," he said. "I would predict the guidelines are going to be rewritten very soon."

The authors of the new guidelines defended the scientific basis of their work, but board members of the AHA and the American College of Cardiology acknowledged there has been a lot of uncertainty about the changes and that the current guidelines could be revised.

Among drugmakers, there are potential winners and losers, whichever way doctors land. Merck's Zetia and Vytorin, which combines Zetia with its statin Zocor, have seen falling sales, combined about $4 billion last year. The two were written off by some analysts after the guidelines changed last year.Those guidelines moved away from basing drugs on getting LDL below a specific to prescribing statins for patients at high risk because they share a family history, or smoke, for example, with those at the higher risk, like diabetes patients, getting the highest doses. The new rules meant a lot of people not taking statins should be prescribed them, favoring drugs like generic Lipitor, but not drugs like Zetia. If doctors start looking to get everyone's LDL very low, then Zetia and Merck's Vytorin might benefit. Also standing to win is a new class of drugs, PCSK9 inhibitors, that are designed to lower LDL by more than 50%. Amgen ($AMGN), Regeneron ($REGN) and Sanofi ($SNY) are working in that arena.

Dr. Matthew Sorrentino, a preventive cardiologist at University of Chicago Medicine, told Reuters he relies on the new guidelines but understands the appeal of having a specific LDL target to shoot for. "Almost everybody knew what the LDL target was," he said. "I can see making the guidelines easier to follow."

- read the Reuters story

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