Questions over the efficacy of Vytorin and Zetia could prompt a sharp pullback on first- and second-line use of the drug, according to a survey of physicians by GfK Market Measures, but docs are taking a wait-and-see approach with the drugs and remain open to new data.

The study found general and family practitioners to be most wary of the drug, with those respondents reporting they will switch upward of 40% of their patients on Vytorin and Zetia to other therapies over the next few months. Cardiologists and internists, by contrast, anticipate switching 25%-30% of their patients off the drugs. Switches will be most precipitous in first-line use (general and family practitioners would switch 20% of patients receiving the drug as a first-line therapy), followed by second-line use (with an anticipated 8%-14% of patients affected across all specialties). Use of the drugs as third-line therapies is likely to increase – by as much as 30% of patients. 
  
“There is obviously an opportunity over the next several months for Lipitor and Crestor to capture additional market share,” said GfK’s Anna Marie Napolitano. “On the other hand, for Vytorin and Zetia, our research shows a window of opportunity to mitigate the impact of the trial results.” The survey found that physicians are counseling patients to wait until their next visit to talk about alternatives, and Napolitano notes that they will be watching closely for the results of the FDA’s review and report on the trial, which is not due until later this year.

The January Internet survey of 150 physicians, including general/family practitioners, internists and cardiologists, was intended to gauge physician reaction to the ENHANCE trial, an imaging study which found that Vytorin was no more effective than simvastatin alone for reducing arterial wall thickness in a small group of patients with a genetic predisposition to hypercholesterolemia.

“We set a high hurdle for ourselves,” said Lee Davies, global director of product communications for Schering-Plough, noting that 80% of the patients in the trial had already been on a statin drug. “The walls were thin to begin with, so we were looking for even further reductions.”

Merck/Schering-Plough has three trials under way measuring outcomes, Davies said. The first, the SEAS trial of 3,500 patients with aortic stenosis, could be available in time for the American Heart Association convention in November. Two more trials are slated to wrap up in 2011 – the SHARP trial involves 5,000 patients with chronic kidney disease and the IMPROVE-IT trial involves 12,500 patients.