The FDA needs to enhance its oversight of drugs approved on the basis of surrogate endpoints, according to a report from the Government Accountability Office (GAO).
The FDA needs to enhance its oversight of drugs approved on the basis of surrogate endpoints, according to a report from the US Government Accountability Office (GAO).
The FDA established its accelerated approval process in 1992 to expedite drug approvals for products that treat serious or life-threatening illnesses. The agency approved 90 such applications between 1992 and 20 November 2008. According to the GAO report, these approvals are based on the drug's impact on a surrogate endpoint, such as blood pressure, rather than on direct clinical evidence such as the drug's ability to prevent a stroke. The agency then relies on postmarketing studies to further assess the drug's effectiveness, which is where problems may come into play.
Specifically, the GAO found that the agency's ability to effectively monitor postmarketing studies is weak. Furthermore, the agency does not have clear procedures for using its authority to withdraw a drug from the market if a manufacturer fails to complete a postmarketing study or if such a study fails to confirm a drug's clinical benefit. The GAO report states that the FDA has never exercised its authority to withdraw a drug in such conditions, even if a required postmarketing study, in one instance, was still not completed after 13 years.
The GAO recommends that the FDA clarify the conditions under which it would expedite the withdrawal of drugs under its accelerated approval process as a way to enhance the agency's oversight.
According to the report, the FDA disagreed with the need for such clarification in its drug withdrawal procedures. Although the agency does have a plan to strengthen its oversight, "the agency has taken a passive approach to enforcing confirmatory study requirements," says the GAO.