Doctors debate Vytorin cancer risk at heart meeting

Researchers attempted on Wednesday to calm concerns about the potential cancer risks of cholesterol fighters Vytorin and Zetia, while others urged caution in prescribing the drugs until larger trials assess their safety and effectiveness.

Hundreds of cardiologists attended the panel discussion at the annual meeting here of the American Heart Association to glean more insights about the advisability of using the drugs sold by Schering-Plough Corp and Merck & Co .

“There is no news here other than undue alarm being raised by some about treatments that may well produce further benefits in terms of reducing the risks of heart attacks and strokes,” said Rory Collins, an Oxford University researcher who is helping lead a large ongoing Vytorin study called Improve-It.

Oxford colleague Colin Baigent, who is conducting a separate large Vytorin study called Sharp, said cancer data in the two ongoing trials was “reassuring. They have shown us at this point no credible evidence of a cancer risk.”

Concerns about a possible cancer link arose in July at a medical meeting in London, when data from a smaller 1,873 patient study called Seas showed substantially more cancer cases among patients taking Vytorin - which pairs a new type of cholesterol fighter Zetia with Merck’s older statin drug Zocor - than those taking a placebo.

A prominent epidemiologist at the London meeting said cancer risk was unlikely because there was a variety of tumor types rather than a more worrisome cluster of a specific cancer. Moreover, he said patients had taken Vytorin a relatively brief time, while it typically takes many years for cancer to develop.

The panel discussion here on Wednesday brought the Vytorin cancer debate to a major U.S. medical forum.

“We believe the outcome of this morning’s Seas debate was unquestionably benign relative to expectations, reinforcing our view that the perceived risk of cancer with Zetia is spurious and that the drug ultimately will be exonerated of this concern,” said Leerink Swann analyst Seamus Fernandez.

Still, the Zetia cancer discussion at the heart meeting stood in stark contrast with data presented three days earlier that demonstrated AstraZeneca Plc cholesterol fighter Crestor dramatically cut the risk of death, heart attack and stroke in a clinical trial, without serious safety issues.

“I think it is impossible to be completely certain, based upon what we currently know, that there isn’t a cancer signal” with Vytorin and Zetia, said Allen Taylor, a cardiologist with Washington Hospital Center in Washington, D.C., who joined Collins in the panel discussion.

Taylor said until ongoing large trials definitely prove the safety and effectiveness of the Zetia component of Vytorin, doctors should avoid prescribing the drugs, except for patients who cannot tolerate other treatments.

“That’s not many of your patients, but it may be some,” Taylor added.

Collins took exception with Taylor’s conclusion.

“The suggestion from (Taylor) that this (cancer risk) may be real is undue alarm because there is no support for the hypothesis generated by the Seas trial,” Collins said.

“We’ve got four times the amount of data in Sharp and Improve-it than the Seas trial and there’s no signal,” he said, referring to larger Vytorin studies. “Those trials are going on and the data monitors of those trials are monitoring both safety and efficacy.”

Sharp is a 9,000 patient trial testing Vytorin in kidney patients, while Improve-it will test 18,000 patients to assess whether the drug actually prevents heart attacks.

Third-quarter sales of Vytorin fell 18 percent to $567 million, while Zetia revenue fell 12 percent to $534 million, hurt by the Seas data and another trial called Enhance, whose results in January cast doubt on Vytorin’s effectiveness, but raised no safety issues at that time.

“Overall, we do not see this panel impacting the Zetia/Vytorin debate,” said JP Morgan analyst Chris Schott in a research note. “We continue to believe we are seeing signs of stabilization for the franchise.”

But Dr. Bruce Psaty, a professor of medicine at the University of Washington in Seattle who moderated the panel, is not going to help boost Vytorin sales anytime soon.

“We have a situation where there is an uncertain potential cancer risk and unknown benefits, so we have a difficult clinical situation about how you represent those risks and benefits to patients,” said Psaty, who has never prescribed Zetia or Vytorin to his patients.

“For Statins, in contrast, there is no increased risk for cancer and there are clear benefits for the prevention of cardiovascular disease, so when I look at a statin versus (Zetia), it’s clear that Statins are indicated for the treatment.”

By Ransdell Pierson and Bill Berkrot
NEW ORLEANS (Reuters)