Prescription Drugs

The Drug Price Competition and Patent Term Restoration Act of 1984 seeks to expand the availability of more effective and affordable drugs by providing the generic drug industry with a simplified and faster review process and brand-name drug companies with an extension of the existing 17-year patent protection. At the time of the law's enactment, drugs for which a patent had been issued and human trials begun were considered "pipeline" drugs and were limited to two-year patent extensions. Legislation (H. R. 1598 and S.1172) has been introduced to allow manufacturers of pipeline drugs to apply for a patent extension beyond that two-year limit. This report compares FDA review and approval times of pipeline drugs with other drugs and examines whether the two-year patent extension granted to pipeline drugs under current law is based on the average length of time for FDA approval of new drug applications. GAO found that approval times for the pipeline drugs on which the study focused were significantly longer than the corresponding average approval times, ranging from 17 to 65 months longer than the average time for comparable pipeline drugs. In general, delays in FDA approval resulted from concerns about safety and efficacy, chemical properties, and manufacturing procedures. Specific concerns varied by drug. Concerning the basis for the patent-extension limit, the legislative history of the 1984 Act does not clarify why a two-year limit for patent extension was chosen for pipeline drugs or why a five-year limit was chosen for other drugs.

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.