UPDATE 3-U.S. to examine data on Vytorin and cancer risk

(Adds company comment paragraphs 14-16)

By Susan Heavey

WASHINGTON, Aug 21 (Reuters) - Concerns that Merck & Co Inc (MRK.N: Quote, Profile, Research, Stock Buzz) and Schering-Plough Corp's (SGP.N: Quote, Profile, Research, Stock Buzz) cholesterol drug Vytorin may be linked to a greater risk of cancer resurfaced on Thursday as U.S. lawmakers and regulators announced new probes into the issue.

The U.S. Food and Drug Administration said it planned to review recently published data that showed a higher rate of cancer in patients taking the combination drug compared to those given a placebo.

The so-called SEAS study, released last month, found 93 cancer cases among Vytorin patients compared with 65 taking a placebo. The companies have said the results are an anomaly and are likely due to chance.

While "most large prospective studies of statin drugs have reported no difference in cancer incidence" between patients taking an active drug versus a sugar-pill, the agency said it would review the data.

"FDA has determined that, to date, these findings in the SEAS trial plus the interim data from ongoing trials should not prompt patients to stop taking Vytorin or any other cholesterol lowering drug," the agency said in a notice posted on its website on Thursday,

It will take about three months before the FDA receives final results from the SEAS study, and it will likely take another six months for it to complete its review and draw any conclusions, it added.

The agency notice is available here

Separately on Thursday, the Democratic chairman of the U.S. House of Representatives Energy and Commerce Committee questioned the two drugmakers' claims that the increase of cancer in Vytorin patients was a fluke.

Rep. John Dingell, along with Rep. Bart Stupak, head of the committee's investigations subcommittee, requested 10 years of company records related to the drug's development, according to a letter sent to Merck and Schering-Plough.

The two Michigan lawmakers also said it is not clear why the study's findings were inconsistent with those from a separate analysis that indicated 102 cases of cancer among those given Vytorin compared with 67 given a placebo.

They also questioned whether the Oxford University researcher who conducted the analysis is as independent as the companies claim, given that the university's same research unit is conducting a separate company-funded Vytorin trial.

"This may be another example of Merck and Schering-Plough playing with the release of a study's data," Stupak said in a statement.

The companies maintain that the increase of cancer cases in Vytorin patients is due to chance but are cooperating with both investigations, Schering-Plough spokeswoman Mary-Frances Faraji told Reuters.

"We do not believe changes in the prescribing of Vytorin are warranted at this time," she said.  Continued...