Peer-reviewed publication of clinical trials completed for pediatric exclusivity

Abstract

Context: Much of pediatric drug use is off-label because appropriate pediatric studies have not been conducted and the drugs have not been labeled by the US Food and Drug Administration (FDA) for use in children. In 1997, Congress authorized the FDA to grant extensions of marketing rights known as "pediatric exclusivity" if FDA-requested pediatric trials were conducted. As a result, there have been over 100 product labeling changes. The publication status of studies completed for pediatric exclusivity has not been evaluated.

Objective: To quantify the dissemination of results of studies conducted for pediatric exclusivity into the peer-review literature.

Design: Cohort study of all trials conducted for pediatric exclusivity between 1998 and 2004 as determined by MEDLINE and EMBASE searches through 2005, the subsequent labeling changes, and the publication of those studies in peer-reviewed journals. We categorized any labeling changes resulting from the studies as positive or negative for the drug under study. We then evaluated aspects of the studies and product label changes that were associated with subsequent publication in peer-reviewed medical journals.

Main outcome measures: Publication of the trial data in peer-reviewed journals.

Results: Between 1998 and 2004, 253 studies were submitted to the FDA for pediatric exclusivity: 125 (50%) evaluated efficacy, 51 (20%) were multi-dose pharmacokinetic, 34 (13%) were single-dose pharmacokinetic, and 43 (17%) were safety studies. Labeling changes were positive for 127/253 (50%) of studies; only 113/253 (45%) were published. Efficacy studies and those with a positive labeling change were more likely to be published.

Conclusions: The pediatric exclusivity program has been successful in encouraging drug studies in children. However, the dissemination of these results in the peer-reviewed literature is limited. Mechanisms to more widely disperse this information through publication warrant further evaluation.

Figure 1

Time from submission of data to the Pediatric Exclusivity Board of FDA and subsequent peer reviewed publication; the y-axis provides the absolute number of publications, and the x-axis provides the time following submission categorized by year.

Figure 2

Publication rates by year of submission; each line encompasses all of the submissions for one year of the program. The y-axis provides the proportion of studies published, and the x-axis provides the time following submission to the Pediatric Exclusivity Board of FDA.