Amendments are viewed as changes to any research documentation that has been reviewed and approved by regulatory authorities and the Sponsor. 

It is the responsibility of the Sponsor to decide whether or not an amendment is substantial.  In addition, the Sponsor must decide whether or not the amendment requires authorisation from the MHRA as well as a favourable opinion from the Research Ethics Committee and HRA approval.

There are essentially two types of amendments.
  • Substantial amendments
  • Non-Substantial amendments

Please refer to SOP and the appendices of Sponsor Green Light Process for Amendments for further information.

Substantial Amendment

Examples of a substantial amendment is a change that is likely to have a significant impact on:

  • The safety, or physical or mental integrity of the trial subjects
  • The scientific value of the study
  • The conduct or management of the study
  • The quality or safety of the Investigational Medicinal Product
  • Changes to the design or methodology of the study, or to background information affecting its scientific value
  • Changes to the procedures undertaken by participants
  • Any change relating to the safety or physical or mental integrity of participants, or to the risk/benefit assessment for the study
  • Significant changes to study documentation such as participant information sheets, consent forms, questionnaires, letters of invitation, letters to GPs or other clinicians, information sheets for relatives or carers
  • A change of sponsor(s) or sponsor’s legal representative
  • Appointment of a new chief investigator
  • A change to the insurance or indemnity arrangements for the study
  • Inclusion of a new trial site (not listed in the original application) in a CTIMP
  • Appointment of a new principal investigator at a trial site in a CTIMP
  • Temporary halt of a study to protect participants from harm, and the planned restart of a study following a temporary halt
  • A change to the definition of the end of the study
  • Any other significant change to the protocol or the terms of the REC application

Non-substantial Amendment

Examples of non-substantial amendments:

  • Minor changes to the protocol or other study documentation, e.g. correcting errors, updating contact points, minor clarifications
  • Updates of the investigator’s brochure (unless there is a change to the risk/benefit assessment for the trial)
  • Changes to the chief investigator’s research team
  • Changes to the research team at particular trial sites (other than appointment of a new principal investigator in a CTIMP)
  • Changes in funding arrangements
  • Changes in the documentation used by the research team for recording study data
  • Changes in the logistical arrangements for storing or transporting samples
  • Inclusion of new sites and investigators in studies other than CTIMPs
  • Extension of the study beyond the period specified in the application form ( If you are requesting an extension to the end date for a portfolio study, please ensure that the funder has agreed to a no cost extension as the NIHR CRN will request evidence of this)

When submitting documents for reviewing, please ensure that you forward:

All amendments are submitted by email to for reviewing.

Substantial amendments will require both HRA and NHS REC approval and if applicable, other regulatory approvals like MHRA or CAG.

Non-substantial amendments only require HRA approval.

For Categorisation emails A and B received from the HRA, you will also require relevant NHS host organisation approval, which we will then issue Sponsor Green Light to implement the amendment.

Amendments that receive a Categorisation C email, we recommend that you inform the NHS organisation of the amendment out of courtesy, please note, we do not issue Sponsor Green Light for Category C amendment as they can be implemented immediately.

HRA Guidance on Amendments  MHRA Guidance on Amendments

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