[9/10/2010] Midodrine is a medication approved in 1996 under accelerated approval for the treatment of symptomatic orthostatic hypotension, a serious condition in which patients are unable to maintain their blood pressure while standing. Shire Pharmaceuticals is the sponsor of the innovator product, marketed as ProAmatine. Five generic drug manufacturers also make the medication.
FDA gave midodrine accelerated approval on the basis of studies demonstrating an improvement in blood pressure, and the company was obligated to conduct post-approval studies verifying actual clinical benefit to patients.
In the time since approval, the company has conducted several clinical studies of the drug, and literature regarding the efficacy of the product has been published, but the data submitted to the agency have not verified the clinical benefit that the drug was expected to have. Many patients and doctors, however, believe through experience that the medication does help patients substantially. We have also heard from several professional organizations that support the use of the product.
FDA has two goals with respect to midodrine: (1) to obtain high quality data on the effectiveness of the medication and (2) to maintain access for patients to the medication throughout this process.
FDA recently notified Shire and the generic manufacturers of the agency's proposal to withdraw product approval for midodrine. The FDA's proposed action was based on the lack of required post-marketing data confirming the clinical benefit of the drug.
A key point is that FDA's announcement did not represent the actual withdrawal of the medication from the market. It represented a step in the regulatory process – a step that reflects both the regulatory requirement for manufacturers to verify the clinical benefit of accelerated approval products and the agency's position that more data about the benefits of midodrine would help doctors and patients understand who can benefit from the drug and how best to use it.
Shire has requested a public hearing in response to FDA's proposal to withdraw midodrine. That hearing will provide an opportunity for the company to present the agency with data supporting the clinical benefit of the drug and for an advisory committee to review those data.
Since the agency notified the manufacturers of the proposed withdrawal of midodrine, we have heard from professional organizations, doctors, and patients about their concern about losing access to midodrine. We have also heard from organizations that have expressed interest in conducting the clinical studies necessary to establish effectiveness, as well as doctors and patients who support the conduct of such studies. FDA intends to work with Shire, the generic manufacturers, and other organizations to discuss the data that are necessary to establish the efficacy of midodrine. FDA will post this information in a public docket.
Midodrine remains approved and available in the marketplace. To reassure patients and their doctors, FDA has stated clearly that as the regulatory process moves forward, continued patient access to midodrine is a key agency priority.
FDA believes that its approach will serve both of its goals – getting the necessary efficacy data and maintaining patient access to the medication while it does so. It is critical to the success of the accelerated approval program that manufacturers of drugs that are marketed under that program perform the studies required to confirm whether the drugs really help people. Ultimately, patients will benefit from understanding more about available therapies and how they work to treat serious and life-threatening illnesses.