Many Factors Affected FDA's Approval of Selected 'Pipeline' Drugs
HEHS-00-140: Published: Aug 10, 2000. Publicly Released: Aug 10, 2000.
- Full Report:
Pursuant to a congressional request, GAO provided information on the Food and Drug Administration's (FDA) review and approval of drug manufacturers' applications to market seven drugs that would be covered by H.R. 1598 and S.1172, focusing on: (1) the review and approval times for the seven pipeline drugs in comparison with other drugs and the factors that contributed to the time FDA required to approve the three of the seven drugs for which the manufacturers agreed to supply GAO with information; and (2) whether Congress based the 2-year patent extension granted to pipeline drugs on the assumption that FDA action on these drugs' applications would occur within the average length of time for FDA approval of new drug applications.
GAO noted that: (1) the times taken to approve the seven pipeline drugs that would be eligible for review under the proposed legislation were significantly longer than the corresponding average approval times for pipeline drugs of the same chemical type and potential therapeutic benefit; (2) in all cases, the time from submission of applications to approval for the seven pipeline drugs ranged from 17 to 65 months longer than the average time for comparable pipeline drugs; (3) in general, the delays in FDA's approving the new drug applications for the three pipeline drugs on which GAO's study focused were a result of concerns about the safety and efficacy of the drugs, as well as their chemical properties and manufacturing procedures; (4) in addition, the applications for two of the drugs filed by the manufacturers lacked essential information; (5) however, the specific concerns varied by drug; (6) for Claritin, there was debate within FDA and with Schering-Plough on the significance of the animal carcinogenicity data for humans; (7) FDA and Schering-Plough also disagreed on how the equivalence of two forms of the drug should be established; (8) regarding Relafen, FDA was concerned about adverse events associated with similar medications and believed there was a lack of information in the manufacturer's new drug application (NDA) on the chemical properties of the drug, including its composition and how it was manufactured; (9) for Cardiogen-82, FDA found the NDA to be incomplete; (10) the agency believed that the data that were initially submitted were insufficient to establish the efficacy of the drug and did not adequately describe the components of the drug and the manufacturing process; (11) the legislative history of the Waxman-Hatch Act does not explain the basis for the patent extension time periods and discusses the use of different extension periods only in general terms; (12) the overall purpose of the patent extensions, according to the House Energy and Commerce committee report, was to create incentives for increased expenditures for research and development; (13) there is not explicit explanation, however, why a 2-year limit was chosen for pipeline drugs or why a 5-year limit was chosen for other drugs; (14) a congressional staff member and pharmaceutical industry representative who were involved in the development of the act have written that the 2-year limit was originally suggested, in part, because it reflected the average NDA approval time; and (15) however, GAO cannot substantiate that contention from the legislative history, and other possible explanations exist.