There was no increased cancer risk with ezetimibe alone or with ezetimibe/simvastatin (E/S) combination treatments, compared with cancer rates of other powerful lipid-lowering statin therapies, according to a post-marketing analysis published in the April issue of the Journal of Clinical Lipidology.
Richard Karas, MD, PhD, professor of medicine at Tufts University School of Medicine in Boston, who co-authored the study along with Tufts colleague, Alawi A. Alsheikh-Ali, MD, from the Institute for Clinical Research and Health Policy Studies, examined the rates of cancer adverse event reports filed with the FDA of patients on ezetimibe (Zetia from Merck) or E/S (Vytorin from Merck), compared these to reports with other potent cholesterol-lowering drugs.
"This real-world examination shows no increased risk to patients taking ezetimibe alone or the ezetimibe/simvastatin combination to lower their lipid levels--an issue that sparked many policy and health safety conversations," Karas said.
The researchers tabulated all adverse event reports listing "cancer" or "malignancy" filed with the FDA (July 2004 to March 2008) of patients taking ezetimibe or E/S, and compared those to reports of patients taking simvastatin, atorvastatin or rosuvastatin. They calculated rates for such reports per million prescriptions, and performed a secondary analysis of cancer reports as a proportion of all reported adverse events for each medication.
The investigators found 2,334 cases of cancers reported in the studied population. They analyzed cancer rates accounting for the number of prescriptions for each treatment dispensed across the U.S., based on a total of 559 million prescriptions (approximately 52 and 55 million prescriptions of ezetimibe and E/S, respectively) for all of the cholesterol-lowering medications evaluated.
The researchers reported that there were 2.9 and 1.3 cancer-associated adverse event reports per million ezetimibe or E/S prescriptions, respectively, compared to a range of 3.1 to 5.1 per million prescriptions for the other drugs. The findings were similar when only reports listing the drug as "suspect" were considered.
The proportions of reports listing cancer relative to all adverse event reports were 2 percent and 1.9 percent for ezetimibe and E/S, respectively, compared to a range of 1.3 percent to 3.9 percent for the other drugs, according to the authors.
Karas and Alsheikh-Ali reported that the reported adverse events do not support that ezetimibe or E/S increase the risk of cancer.
While the authors noted that no specific corporate funding was requested or obtained for data collection, analysis and publication of the findings, Karas has received speaker's fees and/or consulting fees from Merck, Abbott and Schering-Plough and Alsheikh-Ali is a recipient of a faculty development award from Pfizer/Tufts Medical Center.