Amendments process flow chart

This flow chart documents the process for submission of clinical trial amendments to the Competent Authority (CA), Research Ethics Committee (REC), and relevant host organisation.


(1) Examples of substantial and non-substantial amendments are available on the HRA website. The decision as to whether an amendment is substantial or non-substantial is ultimately the sponsor’s.

(2) For studies that received their initial approval before the HRA process change on 31 March 2016, new sites will need to be added using the new HRA process. See the HRA website or contact CTRG for further guidance.

(3) Consider whether the amendment requires MHRA approval even if it does not require NHS REC approval.

(4) Information on HRA categorisation of amendments

(5) In Scotland, Wales or Northern Ireland you should submit the amendment to the REC and copy in

Substantial amendments

If the University is the research sponsor, CTRG reviews and approves all amendments to protocols before submission to regulatory bodies. This is essenntial to insure that indemnity is not affected by the change(s).

A substantial amendment is defined as change to the terms of the protocol or any other supporting documentation that is likely to affect to a significant degree:

  1. the safety or physical or mental integrity of participants
  2. the scientific value of the research
  3. the conduct or management of the research
  4. the quality or safety of any investigational medicinal product used

Addition of new sites, or appointment of a new principal investigator at an existing trial site (for CTIMPs only), are substantial amendments since they change the conduct or management of the research.

If the amendment requires immediate implementation due to safety concerns (urgent safety measures) this must be discussed with the MHRA as soon as possible and a formal amendment submitted within three days.

In all other cases the REC, MHRA (trials only), sponsor and HRA or relevant NHS trusts (where required) must approve substantial amendments before they are implemented.

In order for CTRG and the relevant parties to review and approve amendments all documents must be provided in two formats: the original showing the amended text as tracked changes, and a clean version of the amended document.

Non-substantial amendments

Non-substantial amendments require completion of a notification of non-substantial amendment form.

The sponsor needs to be notified before the non-substantial amendment is submitted to HRA or relevant NHS trusts.

Studies with NHS involvement in England will need assessment and categorisation by HRA. However, for those outside England the relevant NHS trust(s) can assess the non-substantial amendment.

List of site pages