The Virtual International Renal Transplant Trials Archive

Renal Transplant

The Virtual International Renal Transplant Trials Archive (VIRTTA), is a bespoke collaborative venture that brings together existing anonymised datasets from a series of completed renal and transplant trials and registries. These data can be used for secondary analyses to benefit the public and inform future clinical research.

VIRTTA coordinates access to these data and facilitates novel exploratory analyses (e.g. epidemiology, proof-of-concept, end-point optimisation and pilot studies) on large samples. VIRTTA is the extension of its successful sister collaboration, The Virtual International Stroke Trials Archive (VISTA).

What is in it for established investigators?

Combined Datasets

While each contributing investigator has exceptional credibility and already has access to a large dataset, analyses from combined datasets benefit from enhanced statistical power, improved generalisability and greater validity.

Because publications are authored including the byline “on behalf of the VIRTTA Collaborators”, Steering Committee members are specifically acknowledged. Medline credits the listed Steering Committee for the full range of publications that arise.

Members of the VIRTTA Steering Committee can apply to use data from VIRTTA. They may also contribute as co-authors to others’ analyses when they have a major research interest or may delegate their rights to a suitably qualified collaborator.

VIRTTA does not support re-analysis of specific trials or use of trial datasets for meta-analysis of treatment effects originally studied by the trial. Data contributors are each members of the Steering Committee and therefore have influence over the approval of projects. Thus, VIRTTA collaborators will find that they are not relinquishing their rights but instead gaining new opportunities.

What is in it for industry?

VIRTTA is an elegant solution.

Commercial sponsors own the intellectual property residing in trial data collected for a particular purpose. The community, on the other hand, now expects that these data should be made publically available if additional health improvement can be gained without compromising that company’s rights. This raises ethical, scientific, legal and commercial challenges for large companies.  Hence, VIRTTA is an elegant solution, as it is an independent 3rd party platform that analyses and disseminates the data that would be mutually beneficial to the public and commercial sponsors, without compromising any patent or commercially viable aspects.  Where necessary, datasets restricted to control groups can be donated.

Guaranteed protection against re-analysis of data.

Most companies struggle to resource repeated requests for data or for analyses of data held in-house. They also struggle to operate an approvals system for use of the data much beyond the first year or two after the completion of a trial.  VIRTTA takes over these responsibilities and guarantees protection as there is no risk of re-analysis of any data used for a regulatory submission, publication or patent application.  This is crucial to the success of VIRTTA.  Its sister collaboration, VISTA, was successful in obtaining data from large pharmaceutical companies including Glaxo-Smith-Kline, Pfizer, AstraZeneca, Boehringer-Ingelheim, Janssen and Bayer.

Data access, extraction and analyses- at low cost

VIRTTA also offers commercial sponsors and its investigators access to their own contributed data for the purposes of a subgroup analysis, at no extra cost and hassle-free, subject to approval from the original trial’s Steering Committee. VIRTTA should be able to sustain this access for many years. Data are anonymised with regards to trial source, patient identity and are only released with masking of treatment allocation.

Representation on VIRTTA

Sponsors of trials held within VIRTTA may nominate an appropriate academic lead (often the chairperson of their trial Steering Committee) to represent their trial on the VIRTTA Steering Committee. The sponsor may also nominate a company representative to the industry committee or statistical committee.

What is in it for the field?

Taking VISTA as an example, it has provided over 100 peer-reviewed publications, including some that have influenced

  • Research trial design; example: choice of selection criteria and outcome measures in stroke trials
  • Clinical treatment guidelines; example: use of thrombolysis in very elderly stroke patients
  • Regulatory submissions; example: papers on use of thrombolysis in patients with existing cautions and contraindications for intravenous alteplase in acute stroke

VIRTTA may have significant contributions to the fields into which it extends.

How is it funded?

VIRTTA is currently subsidised by the University of Glasgow and will run as a full not-for-profit collaboration in the future. It will derive sufficient income to be self-sustaining from subscriptions from the users of the data and from small grants to support specific projects. There is no charge for data donors to access their own contributed data. For other users and for investigators seeking new data, there is a limited project subscription that covers membership during a project plus the actual cost of extracting relevant data from the archive.  The limited income from these charges will be used to maintain and expanding the archive. Overheads of VIRTTA include provision of administrative and statistical support plus website maintenance.

What assistance can VIRTTA provide for projects?

  • Expert review from Steering Committee on proposals and manuscripts
  • Management and coordination of permissions and feedback
  • Assistance with data selection and extraction
  • Feasibility check on proposed research
  • In-depth knowledge of original trials
  • Opportunity to plan and undertake analysis in Glasgow or work remotely

For more information or to contribute or access trial data, please contact

What are the eligibility criteria for new datasets?

We welcome the contribution of data that meet the following criteria:

  • Minimum dataset of 50 participants, with prevalent kidney transplant
  • Documented entry criteria
  • Documented consent or waiver of consent following local IRB-approved procedure
  • Participants were randomised to their respective treatment arms
  • Assessments were conducted at baseline using a validated assessment tool
  • Demographic and clinical data are available at baseline
  • Follow up assessment was conducted using a validated assessment tool
  • Minimum follow up duration of 6 months
  • Outcomes include kidney function, death, transplant failure, transplant rejection, graft failure, cardiovascular outcomes, etc.


05 Mar 2018

The Virtual International Renal Transplant Trials Archive (VIRTTA) was established in December 2017 and is in the early stages of data recruitment. We look forward to the contribution of study data to this resource.

Steering Committee

A. Jardine
J. Lees
P. Mark