The U.S. Food and Drug Administration may tighten standards for how closely generic drugs resemble brand-name equivalents, said Janet Woodcock, director of the agency’s Center for Drug Evaluation and Research.
Patients and employees of generic-drug makers have told the FDA that some of the medicines don’t work as well as the originals, Woodcock said today in an interview after speaking to the Generic Pharmaceutical Association in Bethesda, Maryland. The FDA is discussing tightening the limits "so there is less variability," she said.
Regulators are focusing on the issue because more prescriptions are filled with lower-cost copies of medicines as insurers try to cut costs and name-brand drugs lose patent protection. Woodcock raised the issue in a speech, and said later that her agency is considering tighter standards.
“Although Dr. Woodcock did not elaborate on her comment relating to therapeutic equivalence, we are always very concerned about any potential problems and look forward to following up with her,” said Bill Head, senior vice president of government affairs for the pharmaceutical association, which represents Mylan Inc. and Novartis AG’s Sandoz division.
Patients have complained about generic anti- seizure medications not working as well as brand-name counterparts, Woodcock said.
Use of generic nervous-system medicines, which include anti-seizure drugs, generated $250 billion in health care savings from 1999 to 2008, according to data from the generic association that Woodcock presented. The savings were the most of the 14 categories of drugs presented, totaling $733 billion.
Brand-name drugs stay on the market an average of 12.8 years before facing generic competition. By the end of their first year, generics can capture nearly 60 percent of market share.
Woodcock told industry executives and employees their colleagues have approached her with concerns at similar conferences. They said some generic drugs have spurred quality concerns that went unnoticed in the approval process because clinical testing includes too few patients.
“They say, ‘I know there are products out there that aren’t equivalent,’ and typically they’re manufacturing folks,” Woodcock said in her speech. “I’ve heard it enough times from enough people to believe that there are a few products that aren’t meeting quality standards.”
The lower-level employees don’t specify which drugs have sparked quality concerns, she said in the interview.
Given the high rate of generic-drug use in the U.S., it’s important for the Food and Drug Administration to continue ensuring that generic products are as safe and effective as the innovator products they copy, said Wes Metheny, senior vice president of the Pharmaceutical Research and Manufacturers of America in Washington, the brand-name drugmakers’ lobby.
David Rosen, an attorney at Foley & Lardner LLP in Washington who served as a top-level generic official at FDA between 1980 to 1989, said questions have long been raised about generic compounds’ effectiveness based on anecdotal evidence. He wondered what is different now.
“I was surprised to hear that Woodcock was questioning the quality without identifying specific products, and I have confidence in the agency’s rigorous review process,” Rosen said.
Woodcock said she didn’t know when the agency would come to any conclusions about generic standards of equivalence. The standards assure the generic is absorbed at the same rate and extent as the brand-name version.
The absorption problems aren’t necessarily harmful, Woodcock said. FDA permits generic drugs to absorb at a 25 percent different rate and extent than the originals they copy.
In April, a group of outside FDA advisers, the Pharmaceutical Science and Clinical Pharmacology Advisory Committee, voted 11-2 that the agency’s equivalence requirements aren’ sufficient for certain medicines. They didn’t offer an alternative, and suggested the FDA list “critical dose drugs,” or drugs where a small difference in concentration can change patients’ reaction, that may need new standards.
At the time, Gary Buehler, FDA’s acting deputy director in the office of pharmaceutical science, suggested such drugs included digoxin for various heart conditions, lithium used to treat manic episodes, phenytoin for a certain type of seizures and the blood-thinner warfarin.
Australia, Canada, the European Union, Japan and South Africa have stricter bioequivalence standards for critical dose drugs, according to slides from Buehler’s presentation to the advisers.
Woodcock also urged generic-drug makers to put more emphasis on “product presentation.”
“Manufacturers need to think beyond therapeutic equivalence,” Woodcock told the industry group.
She urged generic drugmakers to aim to make their pills look more like the original versions. Consumers complain that the low-cost pills often are larger or have rougher coatings, she said.