Public availability of results of ClinicalTrials.gov-registered expanded access studies.

AIMS

Expanded access is the use of investigational treatments outside of clinical trials. Results of expanded access studies provide insights into how investigational treatments work in real-world settings. The objective of this study was to evaluate public availability of results of expanded access studies.

METHODS

Eligible expanded access studies were identified in ClinicalTrials.gov (CT.gov). Publications matching records of individual studies were searched for in Medline and Embase. In addition, we assessed whether results of the included studies were publicly available from other sources including CT.gov, sponsor web sites and conference proceedings.

RESULTS

After median time of 49.5 (interquartile range, 36.7-64.7) months from study completion, the results of 69 out of the 152 included studies (45.39%) were publicly available, either as a journal publication (53 studies; 34.87%) or from other source (16 studies; 10.52%). The percentage of studies whose results were available as a journal publication after 12, 24, 36 and 48 months from study completion was 13.2, 21.1, 33.1 and 35.7%, respectively. The percentage of studies whose results were publicly available from any source (including journal publications) at 12, 24, 36 and 48 months were 19.1, 29.6, 43.2 and 47.5%, respectively.

CONCLUSION

Results of a considerable proportion of expanded access studies are not publicly available. In view of the growing importance of real-world data, sponsors and principal investigators of those studies should always consider making their findings public.