A new study said that a popular class of antihypertension drugs—including those made by Boehringer Ingelheim GmbH, Merck & Co. and Novartis AG—is associated with a modestly increased risk of cancer.
The researchers cautioned that the limited data make it impossible to calculate the exact cancer risk for each individual drug in the class, but said the issue should be investigated further. The study was published online Sunday by the Lancet Oncology medical journal.
The study examined drugs known as angiotensin-receptor blockers, or ARBs, which are used to treat high blood pressure, heart failure and diabetic nephropathy, and to reduce risk of cardiovascular disease. They include blockbusters like Merck’s Cozaar and Novartis’s Diovan, but much of the data in the new analysis was from use of the drug telmisartan, sold under the brand Micardis by Boehringer Ingelheim.
In a written statement, Boehringer Ingelheim said a comprehensive internal safety data analysis of primary data contradicts the Lancet study’s conclusions about an increased risk of potential malignancies. The company said its drug has been studied in clinical trials in more than 50,000 patients, and has a positive safety profile.
Combined sales of Novartis’s Diovan and a related drug, Co-Diovan, were $6 billion last year. Merck’s Cozaar and the related drug Hyzaar had combined sales of $3.6 billion.
Researchers from Case Western Reserve in Cleveland, Ohio, combed through clinical trials published before November 2009 that included any of the seven currently available ARBs and met certain criteria. Though there have been no major safety concerns with ARBs, a study published in 2003 found AstraZeneca PLC’s Atacand to be associated with a higher rate of fatal cancers than the placebo, according to the Lancet article.
The analysis turned up 61,590 patients for which new-cancer data were available, and cancer death data for 93,515 patients.
The researchers found patients randomly assigned to receive ARBs had a 7.2% risk of developing a new cancer, versus 6% in control groups in the studies. Among specific solid-organ cancers examined, only new lung-cancer incidence was significantly higher in ARB recipients than control groups, 0.9% versus 0.7%.
There was, however, no statistically significant difference in cancer deaths between groups.
The authors said one of the limitations of their analysis was that the trials they examined weren’t designed specifically to explore cancer outcomes as the primary goal.
Steven Nissen, a cardiologist at the Cleveland Clinic, wrote in an accompanying commentary in the Lancet that regulators should review any links between ARB use and cancer.
“In the interim, we should use ARBs, particularly telmisartan, with greater caution,” Dr. Nissen wrote. “These drugs are often overprescribed, as a result of aggressive marketing and in the absence of evidence that they are better than angiotensin-converting enzyme (ACE) inhibitors,” another class of drugs.
Dr. Nissen, who is known for flagging drug safety issues, said ARBs should be reserved for patients with intolerance to ACE inhibitors, which are largely available as generics.
A Merck spokesman said the company stands by the efficacy and safety profile of Cozaar. An AstraZeneca spokesman said the company would review the study. Other manufacturers couldn’t be reached for comment.
Write to Peter Loftus at peter.loftus@dowjones.com
