Summary of results

Irrespective of the outcome of a clinical trial, within one year from the end of a clinical trial in all Member States concerned, the sponsor shall submit to CTIS:

Where, for scientific reasons detailed in the protocol, it is not possible to submit a summary of the results within one year, for example when the clinical trial is still ongoing in third countries and data from that part of the trial are not available, which makes a statistical analysis irrelevant, the summary of results shall be submitted as soon as it is available. In this case, the protocol shall specify when the results are going to be submitted, together with a justification.


A sub-study is a study which is part of a clinical trial, related or not to its primary objective, where clinical trial subjects could also voluntarily participate, provided that they give an additional informed consent. Examples are pharmacokinetic or pharmaco-genetic sub-studies. If a sub-study is described in a separate protocol it will be considered to be a separate clinical trial.

If sub-studies are described in the main protocol they should have the same end date as the main clinical trial. If sub-studies are introduced in the protocol, following the submission of a substantial modification, Member States shall assess whether it is acceptable to postpone the end date of a clinical trial if a sponsor so requests. Publication of the results of a sub-study should not cause any delay in the publication of the summary of the available results of the main parts of the clinical trial.

The results of a sub-study described in the protocol of the main trial should be published together with those of the main clinical trial.

See also questions 6.1-6.4 of the CTR Q&A.