Despite regulatory requirements and industry commitments, analyses of clinical trial transparency rates continue to report that not all clinical trial results are published within the required timelines, or at all.
In 2012, the Association of the British Pharmaceutical Industry (ABPI) initiated a study to assess the timely disclosure of results of company sponsored trials related to all medicines approved in Europe over a continuous three-year period (2009–2011). The authors found that 77% of all trials were disclosed within 12 months and almost 90% were disclosed by the end of the study. The investigation was extended for 2012, and demonstrated an improvement in results disclosure within 12 months to 90%, with an overall disclosure rate of 92% by the end of the study. The results for a second extension (for trials related to medicines approved in 2013) have just been published.
All completed company-sponsored trials related to each new medicine approved by the European Medicines Agency in 2013, carried out in patients and recorded on a clinical trials registry and/or in a European Public Assessment Report (EPAR), were included in the assessment. Overall, 606 completed clinical trials associated with 34 new medicines licensed to 24 different companies were identified. Of the evaluable trials, results of 90% had been disclosed within 12 months, and results of 93% had been disclosed by the end of the study (31 July 2015). A significant proportion of the trials which remained undisclosed were early Phase I or II trials, however, many were initiated before industry disclosure commitments or requirements were first published.
The authors acknowledge some limitations associated with the study, including the ongoing publication of results not clearly linked (for example, by inclusion of a trial registration number) to the trials they report, despite recommendations from the International Committee of Medical Journal Editors and the World Health Organization. Nonetheless, the data suggested a significant trend towards increasing rates of results disclosure at 12 months over the continuous five-year period assessed. While these results are encouraging, the authors assert that there is still some room for improvement to meet recommended transparency requirements.