Pfizer announced today it will sponsor a major clinical study to further assess its COX-2 medication Celebrex in osteoarthritis patients at high risk for cardiovascular disease. In a press release, Pfizer said the new study is part of a larger cardiovascular exploration program with Celebrex that started over 18 months ago. The new trial, which will be conducted at major universities and hospitals around the world, is expected to start early in 2005 and will enroll more than 4,000 patients who have had a recent heart attack and who also have a history of osteoarthritis. Pfizer will be discussing the study design with the FDA and other regulatory agencies prior to finalizing the details and start date. Pfizer maintains it is confident about the cardiovascular safety of Celebrex even suggesting Celebrex "may improve vascular function in patients with established coronary artery disease."