Dr. Janet Arrowsmith-Lowe, M.D., F.A.C.P., offered the following expert report on Wyeth’s behalf in the case of Wright v. American Home Products.
C. FDA Approvals of Pondimin and Redux
I agree with the FDA that the NDA data for Pondimin and Redux supported a conclusion that the drugs were safe and effective when used in accordance with their labeling. In other words, the potential benefits outweighed the known risks. My opinions on the adequacy of the data and labeling are based on my reviews of NDA data, FDA's reviews of the data, and my experience with the FDA review processes.
The FDA determined that the data submitted for Pondimin established the safety and efficacy of the drug for short-term use as adjunctive therapy for the treatment of obesity. Pondimin was found to have a lower abuse potential than amphetamine-like drugs, which for many years had been used widely as appetite suppressants.
The Redux NDA contained extensive information on safety and effectiveness. This included years of widespread use in Europe where it had been marketed since the mid-1980s. Included in the NDA were controlled clinical trials of up to one year duration demonstrating safety and effectiveness, as well as detailed post-marketing safety reports. The studies demonstrated that dexfenfluramine was more effective than placebo in promoting weight loss, when administered to patients with instructions regarding diet and activity.
Also included in the Redux NDA were results from the International Primary Pulmonary Hypertension Study (IPPHS), which addressed the risk associated with anorexigen drug exposure in the development of primary pulmonary hypertension (PPH). The FDA also convened an Advisory Committee to review the safety and effectiveness of Redux, including data relating to PPH. The FDA was well apprised of the risk of PPH in patients who took Redux and Pondimin before the NDA was approved. After reviewing the data on PPH and the IPPHS, as well as the post-marketing safety data from Europe, the Advisory Committee recommended the approval of Redux based on a favorable risk-benefit ratio. FDA approved the drug for marketing in the United States in April 1996. In my opinion, the initial Redux labeling adequately and appropriately conveyed the safety data learned in both the pre-approval studies and the European post-marketing experience with dexfenfluramine.
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