The demand for clinical trial transparency and research results continues to gain momentum, as it was recently reported that almost half of the data from randomized clinical trials (RCTs) from four sponsors registered at were not available to researchers.1

The glass-half-full take on this is that 53% of the RCT data from the four sponsors were accessible on the Clinical Study Data Request (CSDR) website, where companies can voluntarily list data that has been requested.

The researchers targeted studies on 61 drugs from four sponsors registered at A total of 521 RCTs (53% of total reviewed) were listed on CDSR. The availability of various documents and findings in the RCTs varied from 83% to 99% on many studies, but 385 trials (40%) had all documents listed. Again, 47% of the clinical trials from the four sponsors were not listed on CSDR.

Lead study author Isabelle Boutron, MD, PhD, of Paris Descartes University, replied to questions from IRB Advisor via email.

IRB Advisor: Can you comment on disincentives for companies to release all data?

Boutron: First, I think it is important to be careful when interpreting these results. The listing of trials on CSDR is a recent and an ongoing process and the number of studies listed is increasing. It is important to acknowledge that it may take some time and effort to give access to these data. Further, we considered all the trials registered and we did not take into account the policy of the sponsor.

However, our results showed that a substantial number of trials were missing and we could imagine that the study results may influence the willingness to share data. Nevertheless, our study did not explore this hypothesis.

IRB Advisor: How might full release of research data aid other researchers and, ultimately, patients?

Boutron: The full release of research data is very important to improve evidence-based medicine as it will allow access to unpublished data and the conduct of individual patient data meta-analyses. This would increase our understanding of the efficacy and safety of treatments and improve the care provided to patients. It could also allow improving clinical research as we could explore factors associated with better research.

IRB Advisor: Can you comment on why you undertook this study and whether you support calls for data transparency for all RCTs by groups like the AllTrials campaign?

Boutron: We undertook this study because we felt the initiative of pharmaceutical companies to share their data is a very important initiative. We definitely support calls for data transparency for all RCTs by groups like the AllTrials campaign. We are members of the EQUATOR network, Cochrane, and the REWARD Alliance, and we call for more transparency and reduced waste in research.


  1. Boutronn I, Dechartres A, Baron G, et al. Research Letter: Sharing of Data From Industry-Funded Registered Clinical Trials. JAMA 2016;315(24):2729-2730.