3Rs-Centre Utrecht Life Sciences

Faculteit Dierengeneeskunde

April 2018
Promoting transparency in preclinical research: preclinicaltrials.eu

Imagine a database in which all animal study protocols can be found. This would reduce the number of animal experiments, enhance collaborations and knowledge sharing, and improve the quality of preclinical research. Such a database is now a reality; at the University Medical Center (UMC) Utrecht, Mira van der Naald and her colleagues initiated the Preclinical Trials database: preclinicaltrials.eu.

Although the need for a preclinical trials database existed for some time now, PhD candidate Mira van der Naald decided to take action, with the support of her supervisor Steven Chamuleau. Van der Naald is a medical PhD candidate at the department of Cardiology at the UMCU. “My colleagues and I have performed multiple preclinical meta-analyses,” explains Van der Naald. “However, we were aware of the risk of publication bias and thus realized we could not easily access all the preclinical data. A database with pre-registered study protocols would provide a solution for this.” Although the database was initiated in the field of regenerative cardiology, its target audience entails the entire biomedical field.

International momentum  
Van der Naald and her colleagues were not the only ones thinking about how to solve problems caused by lack of transparency in the current practice of preclinical research. Over the past few years, several organizations have been dealing with this in parallel1. The Open Science Framework was concerned about this topic, as well as the international consortium TACTICS (Transnational Alliance for Regenerative Therapies in Cardiovascular Syndromes), that recently published a position paper with an important conclusion: “To increase the usability and translational value of preclinical studies, the quality of preclinical research needs to be improved, collaborative efforts need to be promoted and the sharing of knowledge and protocols should be enhanced. Furthermore, in order to increase transparency and minimize bias, preclinical studies should be pre-registered in an open-access database2. This paper, together with the international momentum around transparency in preclinical research, provided support from the medical field to start building the preclinical trials database.

Van der Naald invites every researcher to pre-register their preclinical studies in the database. “An initiative like this needs broad support in order for it to be effective and useful to others”, she explains. “We started with the registration of our own studies, to set an example for the scientific community.” The database has an embargo option, which allows the users to keep their registration hidden for a year. The embargo period can be prolonged upon request. This answers to the request from researchers who were enthusiastic about the database, but were worried about providing the competition with valuable details about studies that still need to be performed. Van der Naald hopes that this embargo will convince the scientific community that this database will encourage transparency at a low risk for their scientific output. Van der Naald would also like to add preclinical trial protocols retrospectively, in addition to prospective protocols of studies that still need to be performed. After all, not all preclinical trials have been published, therefore adding their protocols to the database will counterbalance publication bias. Additionally, preclinicaltrials.eu provides the possibility to add a persistent identifier linking to any repository with results. In this way, unpublished results can be shared. Thus, this will increase the value of the database as scientists can be kept up to date with the previous work of their colleagues, at least until it has become common practice to pre-register every animal study.

The preclinical trials database

Future aims

The preclinical trials database was officially launched on 11th April, at a scientific meeting organized by the Netherlands Heart Institute. Members of the scientific community were invited, as well as funding organizations like the Dutch Heart Foundation. According to Van der Naald, funding agencies have a crucial part to play in promoting transparency through preregistration. She would like to see that funding organizations stimulate applicants to preregister all confirmatory studies that are described in a grant proposal. That way, being transparent about your research plans will become common practice. This in turn will improve study quality, stimulate knowledge sharing and reduce the unnecessary duplication of animal studies. Besides convincing funding organizations, Van der Naald and her colleagues also aim to discuss with other stakeholders, like journals and reviewers, institutes, researchers and policy makers.
Mira van der Naald has almost finished  her PhD study, after which she will start a new job at the Medisch Spectrum Twente hospital in Enschede. Nevertheless, she will continue to work on the dissemination of the preclinical trials database, because she finds it important to do so. Although the Netherlands Hearts Institute will provide for the maintenance of the database, there is still a long way to go in promoting the pre-registration of animal studies. Van der Naald points out that transparency is important for every researcher, and that all researchers can take responsibility in this matter. “The momentum that exists now is exciting; everyday new people subscribe to the website. This is the time to move forward and turn transparency into common practice.”


1. Jansen of Lorkeers, S. J., Doevendans, P. A., & Chamuleau, S. (2014).
All preclinical trials should be registered in advance in an online registry. European journal of clinical investigation, 44(9), 891-892.

2. Chamuleau, S. A., van der Naald, M., Climent, A. M., Kraaijeveld, A. O., Wever, K. E., Duncker, D. J., ... & Bolli, R. (2018). Translational Research in Cardiovascular RepairTake-Home Messages: A Call for a Paradigm Shift. Circulation research, 122(2), 310-318.