Another key piece of evidence is a 2001 warning letter the U.S. Food and Drug Administration wrote to Merck which said a promotional campaign for Vioxx "minimizes the potentially serious cardiovascular findings" observed in the Vigor study and that it "misrepresents the safety profile for Vioxx."
The letter said Merck failed to disclose that its explanation about naproxen was a hypothesis with no adequate studies to support it and that another reasonable explanation for the increased heart attacks is that Vioxx may help cause blood clots.
On Tuesday, the U.S. Food and Drug Administration released a study that said Vioxx may have contributed to an additional 27,785 heart attacks or deaths from 1999 to 2003 that might have been avoided if patients were taking Pfizer Inc.'s Celebrex. The study analyzed medical records of 1.4 million adult members of Kaiser Permanente, the nation's largest HMO. Preliminary findings were released in August.
The report also found that naproxen had no cardioprotective effects, disputing Merck's contention.
The estimates in the Merrill Lynch report are based on data from the Kaiser Permanente study.
Doctors interviewed for this story also had complaints about Merck, saying the company tried to squelch negative opinions on Vioxx's safety and downplay the drug's risks.
Stanford University medical professor Dr. James Fries said a high-ranking Merck official, Dr. Louis Sherwood, tried to intimidate several doctors who expressed concerns about Vioxx's safety. Fries said Sherwood made charges to these doctors' superiors that the physicians were biased against the drug.
Fries said he received such a call about one of his doctors and learned it was part of a pattern. He said he wrote Merck chairman Raymond Gilmartin protesting the company's attempt to suppress academic discussions.
"I think Merck went over the line," Fries said. "Their approach was to try to get people fired for saying things they (Merck) didn't agree with."
Fries said the calls stopped after his letter, which he said was sent in 2000 or 2001.
