Panel recommends FDA to not create specific effectiveness standard for oral contraceptive approvals

Jan 28 2007

A panel of gynecologists, researchers and other medical experts on Wednesday at the end of a two-day meeting convened by FDA recommended the agency not set a specific standard of effectiveness for approval of oral contraceptives, the AP/Minneapolis Star Tribune reports (Bridges, AP/Minneapolis Star Tribune, 1/25).

The agency is reviewing the standards it uses when considering approval of oral contraceptives, and it asked the panel to make recommendations on the standards. Higher pregnancy rates in studies of new low-dose oral contraceptives have prompted the agency to reconsider what represents an "acceptable failure rate" for new drugs. The agency uses a measurement called the Pearl Index, which calculates a contraceptive's failure rate by measuring the amount of time women are exposed to a given product and the number of unplanned pregnancies that result. According to FDA documents released last week, the agency in the 1970s set a policy that it only approved oral contraceptives with failure rates less than 1.5 per 100 "woman-years," or the number of years a woman has used the drug. FDA has recently approved some pills with failure rates of more than two per 100 woman-years. The agency said that the number of pregnancies in clinical trials has increased in new oral contraceptives with lower dosages of estrogen and progestin. The increase in pregnancies is "consistent with less sustained ovulation suppression in new products as compared to the earlier higher-dose regimens," but there might be other reasons, FDA said (Kaiser Daily Women's Health Policy Report, 1/24). "You might have a product that has a higher failure rate but has all kinds of benefits," panel Chair Charles Lockwood of Yale University said, adding, "We were uncomfortable being pinned down to a specific number" (Stein, Washington Post, 1/25). Panelist Paul Blumenthal of Stanford University suggested the agency establish different classes of oral contraceptives based on their effectiveness (AP/Minneapolis Star Tribune, 1/25).

The panel on Tuesday recommended the agency enroll more overweight women in clinical trials and said that the Pearl Index is outdated and FDA should abandon it (Kaiser Daily Women's Health Policy Report, 1/24). The panel also recommended FDA require pharmaceutical companies to enroll smokers, teenagers and women older than age 35 in clinical trials of oral contraceptives so that they are more representative of the general population, the Post reports (Washington Post, 1/25). In addition, the panel recommended that pharmaceutical companies conduct post-market trials on new oral contraceptives to determine whether negative side effects were overlooked in clinical trials. The panel said the cost associated with post-market trials and the potential negative effects that could be discovered likely would deter companies from lunching the studies, Reuters reports (Heavey, Reuters, 1/24). Although the agency is not required to implement the panel's recommendations, Scott Monroe, acting head of FDA's reproductive drugs division, said the agency is "likely to implement" all of them (Washington Post, 1/25).