Merck & Co researchers are said to have become concerned over the safety profile of Vioxx following a study in March 2000, which found the drug to raise the risk of heart attack. Company scientists therefore considered combining Vioxx with another agent to reduce the chance of cardio events.
The evidence comes from an internal memo between Merck’s researchers and patent department which was mistakenly given to plaintiff lawyers during one of the many legal battles over the Vioxx drug. Thousands of death and injury claims have been filed against the company in relation to the drug. Analysts estimate Merck’s total liability could amount to over $18 billion.
According to MarketWatch.com, US law firm Hughes Hubbard & Reed confirmed Merck filed a patent application for the new formulation of the drug.
Merck’s highly successful painkiller was abruptly withdrawn from the market in September 2004 following clinical evidence which linked long-term use of the drug to an increased risk of heart attack and stroke. Company executives have since faced accusations of ignoring early warning signs that the drug could potentially cause such cardiovascular problems.
More positive news for Merck comes from recent results of a phase II clinical trial with gaboxadol, an investigational agent for the treatment of insomnia and the first of a new class of sleep agents known as selective extrasynaptic GABAA agonists (SEGA).