The US Food and Drug Administration (FDA) approved just 1% of original Abbreviated New Drug Applications (ANDAs) sent to it by generic drug makers in 2006, and “tentatively approved” another 3%, but rejected the remaining 96% because they failed to meet the agency’s review standards, according to a new government report.

US federal law requires the FDA to approve, tentatively approve or disapprove original ANDAs within 180 days of receipt. However, in 2006 the agency exceeded this time limit for 46% of the original approval applications for generics because their chemistry reviews exceeded 180 days, taking in fact an average of 217 days. Moreover, for 69% of the delayed reviews the agency did not even begin work until the 180 days was up, says the report, which is published by the Office of Inspector General (OIG), Daniel Levinson, of the Department of Health and Human Services (HHS).

For 76% of the generic applications whose review times exceeded 180 days, this was due to delays in microbiology reviews, while 58% of the delays were in bioequivalence and 56% were in labelling. For the application reviews going over the 180-day limit, median review times were 361 days in microbiology, 287 days in bioequivalence and 277 days in labelling.

Generic drugs are generally seen as one way of reining in the USA’s growing health costs, and submissions to the FDA for their approval have increased at a level more than double the rate of the agency’s review resources in the last five years, says the OIG report. To manage and speed the process better, it calls on the agency to identify the most common problems leading to delay or rejection, and offer more guidance to industry.

The FDA's Office of Generic Drugs (OGD) also needs to increase the percentage of applications reviewed by all divisions within 180 days, and take steps to prioritise and reduce the review times for those applications which can be approved and marketed immediately, adds the OIG. Agency policy defines high- and low-priority consultations based, in part, on whether the application is close to approval, and establishes review timeframes based on these priority levels; however, the IOG investigators found that, in practice, consultation results are not generally returned to the OGD within specified timeframes, regardless of priority level.

In its comments on the OIG's findings, the FDA points out that it has already taken action to: provide guidance to industry in submitting more easily-reviewed applications; develop a focused hiring programme to increase staff and decrease review times; and prioritise some applications based on their potential market entry date. A further option could be to delay reviews of generics which are based on patents that expire far into the future, the agency suggests, but it also warns that such a process would require policy changes within the OGD.