Internal FDA Dispute Continues Over Popular Blood Pressure Drugs and Cancer LinksJun 3, 2013
Some popular blood pressure medications are at the center of an internal ruckus at the U.S. Food and Drug Administration (FDA).
Angiotensin receptor blockers (ARBs) are sold in the United States under brands such as Novartis AG's Diovan, Daiichi Sankyo Co.'s Benicar, Merck & Co.'s Cozaar, Boehringer Ingelheim GmbH's Micardis, Sanofi SA and Bristol-Myers Squibb Co.’s Avapro, and Atacand by AstraZeneca PLC. The drugs, which are taken by millions of people, are prescribed to prevent heart attack, stroke, and heart failure, according to The Wall Street Journal.
A 2010 study published in Lancet Oncology indicated that Ilke Sipahi and colleagues at University Hospitals in Cleveland analyzed five studies involving 68,402 patients. The team found that people taking ARBs experienced an 11 percent increased risk of developing new cancer overall and a 25 percent increased risk of developing new lung cancer, compared with patients who did not take ARBs, the Journal indicated.
A senior regulator at the agency, Dr. Thomas A. Marciniak, is now seeking stronger warnings for ARBs, according to internal documents reviewed by the Journal. Other FDA officials disagree and say that there are no links between ARBs and cancer. The issue points to the focus the FDA places on drug reviews of heavily marketed blockbuster medications while new drugs are being released to the market. Dr. Marciniak seeks to place increased emphasis on ARB safety as opposed to focusing on new drug applications, according to the Journal.
The agency combined a number of different studies to see the side effects in patients taking ARBs—a meta-analysis, explained the Journal. Researchers point out that if the original studies are flawed, the meta-analysis will compound those flaws. "Garbage in, garbage out," wrote Dr. Marciniak, saying that looking at findings provided by drug companies would likely produce unreliable results.
For instance, in an FDA analysis reviewed by the Journal, Dr. Marciniak said the agency’s meta-analysis did not consider lung carcinomas as lung cancers, even though they are. Dr. Marciniak went through the raw data, patient by patient, and concluded that lung cancer risks increased by 24 percent in ARB patients, which he said is statistically significant, according to the Journal. In fact, in 10 out of the 11 studies he reviewed, there were more cases of lung cancer in the ARB group than in the control group.
He sent a memo to senior FDA officials, saying: "The FDA needs to inform patients and physicians about the ARB lung-cancer risks. The FDA must act now." Dr. Unger, the FDA division chief, said he disagreed, wrote the Journal.
Other experts agree with Dr. Marciniak, most notably, Dr. Sipahi, who authored the 2010 study, wrote the Journal. "I have no doubt that ARBs increase cancer risk." Also, Cleveland Clinic cardiologist Steven Nissen told the Journal that the FDA "has a huge advantage over academic researchers [in terms] of having access to patient-level data" that it has not completely reviewed. "Until I see such a rigorous analysis, I remain concerned about the ARB cancer problems," he said.
During his residency at the Mayo Clinic, Dr. Marciniak specialized in cancer. Before joining the FDA, he spent 10 years at the National Cancer Institute, the Journal wrote.