Gap in publication of comparative information on new medicines

AIMS To determine the time-lag between the EU authorization of new medicines and the publications of the main randomized active control trials (RaCTs) used in the authorization process and to compare unpublished with published RaCTs of the same medicine. METHODS All RaCTs for new medicines with a new active substance, authorized between 1999 and 2003, were extracted from the European Public Assessment Reports (EPAR). Information about the publication status of RaCTs was obtained from the MEDLINE and EMBASE databases. RESULTS We identified 116 RaCTs for 42 new medicines; 28% of the RaCTs had been published at the moment of market authorization, 59% after 1 year, 78% after 2 and 83% after 3 years. Most of the rest of the studies remained unpublished after 3 years of follow-up. Unpublished RaCTs differed from published trials of the same medicine especially regarding therapeutic use and/or comparator. In some cases unpublished trials have influenced the risk : benefit asssessment of the registration authorities. CONCLUSIONS Most of the main RaCTs, relevant for assessing the added value of a new medicine, are published subsequent to market entry; some of these trials remain unpublished. We argue for a standardized public registration of the results of the main premarketing clinical trials as a condition for market authorization.