ALBANY -- New York State Attorney General Andrew Cuomo on Saturday said he has subpoenaed drug companies as part of an investigation into whether they concealed the results of research that found a brand-name drug was no more effective than a cheaper, generic alternative.

Cuomo said his office is investigating whether Merck & Co., Schering-Plough Corp. and a joint venture of the two companies defrauded consumers and investors with their aggressive marketing of the cholesterol-lowering drug Vytorin.

Last week, the two companies released partial data from a study that showed Vytorin didn't reduce plaque buildup any more than a generic alternative that costs about two thirds less.

“Drug companies are on notice that concealing critical information about lifesaving prescription drugs, profiting at the expense of patients

health, and wasting taxpayer dollars, is simply unacceptable,“ Cuomo said.

Vytorin is a combination of a Merck drug called Zocor -which is also available as a generic - and Schering-Plough's Zetia. The two companies began marketing Vytorin under a joint venture in 2004.

The study was meant to show how well Vytorin limited plaque buildup in neck arteries in people with high cholesterol levels. But it showed Vytorin was no more effective at that - and perhaps a bit worse - than Zocor alone.

Chris Garland, a Merck spokesman, said the company will cooperate with the attorney general's investigation and it stands by the safety and efficacy of the drugs.

Cuomo said he is investigating whether the company violated New York consumer protection laws by aggressively marketing the drug to “unsuspecting patients and doctors.”

Investigators also are probing insider stock sales and whether the companies' statements to investors were accurate, Cuomo said.

AP-ES-01-26-08 1538EST