What doesn’t work with Phase IV studies? A real experience from an Ethics Committee

Abstract

Phase IV studies are conducted in real-life conditions to expand the knowledge on the efficacy and safety of an approved drug. Carried out either in hospital or general practice setting, they can be distinguished in Phase IV trials and post-marketing surveillance studies. Limited information is available in Italy about their characteristics as the proportion of observational studies, the average size and the importance of the non-sponsored research. In order to investigate these and other features, we analysed 1,881 protocols presented to the Ethics Committee of a large size University Hospital in the decade 1999-2008. Out of the 188 (10%) Phase IV studies, about three fourths were controlled clinical trials, 48.4% had an active drug and 16.0% a placebo as comparator; only 8.5% was presented as observational. Most of the Phase IV studies could be classifiable as Phase IIIb. The median sample size value was 200 patients, while the Phase III studies reported a median of 360 patients, this contradicting the “large-scale” characteristic of the Phase IV studies reported in the literature.