Submitting amendments to EC Research

Conditions for submitting and approving amendments

Clinical Trial Regulation (CTR)

Changes to studies falling within the scope of CTD can be submitted to EC Research UZ/KU Leuven. Please note that from January 31st, 2025, all active trials need to be conducted under CTR.


An amendment can only be approved if:

  • The EC previously formulated a favourable opinion regarding the initial protocol.
  • An annual progress report was submitted (from the date of EC approval). If the study has not been terminated within one year, ICH-GCP requires an annual progress report to be submitted to EC. A template can be found on this website.

General remarks about submitting amendments

  • A distinction is made between 'Substantial amendments' and 'Amendments for participation of additional centres in a previously approved study' (see overview at the bottom of these general comments).
  • All centres participating in a particular study should have identical, finally approved (versions of) documents.
  • The previous paragraph shows that the documents (IB, IC, etc.) submitted in the context of an amendment for participation of additional centres in a previously approved study should not differ from the finally approved (versions of) documents available to the other centres.
  • Please always clearly specify the reason(s) for submitting a (substantial) amendment in the cover letter and indicate the changes in the amended documents.

Changes to information for participants

In case of changes to the information provided to participants (ICF), it is highly recommended to use an ICF addendum for  current participants. The ICF addendum only lists the amendments or new information that is clearer to the participant than an amended ICF where changes are highlighted.

Submitting amendments

Amendments can only be submitted digitally. Read more about submitting documents.


Last edit: 7 April 2023