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This page contains information for those involved in the submission of applications for Clinical Trials of Investigational Medicinal Products (CTIMPs).

The combined review service, formerly called Combined Ways of Working (CWoW) will become the way all new CTIMP applications are made from 1 January 2022. It offers CTIMP applicants and sponsors a single application route and co-ordinated review leading to a single UK decision.

Combined review should now be used for all new CTIMP applications. If you’re a first-time user, please contact us at for help to get started.

If you do not have applications coming up, there are important differences in the service to understand and actions to take in preparation for the changes. These are explained below, along with specific information for those involved in the submission of combined investigational medicinal product and medical device trials. Please visit our contents section to find out more.

Please note: CTIMP applications via combined review must be submitted using a new part of the Integrated Research Application System (IRAS) and should not be started in the standard part of IRAS.

Combined review

The benefits of using combined review

The combined review service offers a single application submission and co-ordinated review leading to a single UK decision for Clinical Trials of Investigational Medicinal Products (CTIMPs). It was developed by the HRA and the Medicines and Healthcare products Regulatory Agency (MHRA), working closely with the National Institute for Health Research (NIHR), Clinical Research Networks and the devolved administrations.

Benefits for CTIMP sponsors, Contract Research Organisations (CROs) and investigators include:

  • a single application for Clinical Trial Authorisation and Research Ethics Committee (REC) opinion
  • a co-ordinated review process that ensures REC and MHRA outcomes are consistent and aligned
  • a streamlined and efficient application process – a single submission; a coordinated review; combined communications to request further information; and a single communication to confirm the final decision - some users report a 30 per cent improvement in overall trial set up times
  • a single unified request for changes or clarifications from the MHRA and the REC
  • REC opinion and MHRA authorisation delivered together
  • the same streamlined application and review process for subsequent substantial amendments to the trial authorisation
  • improved access to the NIHR Clinical Research Network (CRN)’s Study Support Service for researchers, with the opportunity to apply for support earlier and receive an eligibility decision sooner through the CRN’s new Non-commercial Portfolio Application service

What should sponsors and CROs be doing now to prepare?

Combined review should now be used for all new CTIMP and combined IMP/device trials. Sponsors and investigators are advised to familiarise themselves with the process and where possible, gain experience of using the service early.

As applications are completed and submitted in a new part of IRAS, the following preparations are needed:

  • register for an account in the new part of IRAS
  • sponsor organisations are selected from existing options in IRAS. If your organisation does not appear on the list, send the full name of the organisation and the sponsor contact e-mail address to so the details can be added to the system
  • ensure you are aware of the key guidance documents - links below
  • identify upcoming trials to submit via the combined route
  • contact us for support with your first combined review application at

We recommend you complete the first three steps now. This will help avoid any delays and ensure you are ready to begin an application. You should also consider any impacts on your internal processes and procedures.

What’s different about the new system?

Submissions via the combined service have some key differences. They are:

  • You must submit to the REC and the MHRA together; there is no provision to make separate submissions via this process.
  • You will be offered REC meetings that correspond to the date of submission, so you may not see your local or usual REC listed when you make your booking.
  • Once the application is complete and is booked to the REC meeting, the sponsor or their delegate must complete the final authorisation step before the REC meeting cut-off date.
  • Individuals can view and revise the application information in the system instead of generating a PDF of an in-progress application. You may need to think about how things like QC processes can be undertaken within the system instead of generating a PDF. You can give collaborators view-only or read-write access to the system for this.
  • Messages from the system (for example requests for further information or a final outcome issued) only go to a specific set of contacts. Therefore, if organisations have different teams working on different parts of the application, you must have effective internal communication mechanisms in place.
  • You will receive a consolidated initial outcome. If there is anything that needs to be addressed for the trial to be approved, you should respond within approximately 14 days. This improves the efficiency of the overall process, and is in line with the existing MHRA arrangements.

Combined trials of an investigational medicinal product and an investigational medical device (IMP/Device trials)

From 1 January 2022, the combined review service will also become the way that all IMP/Device trial applications are made. Further details and guidance about this will be provided shortly. For now, IMP/Device trial applications should continue to be created and completed using the standard part of IRAS.

If you have any queries, please contact us at

Webinars for CTIMP applicants, sponsors and NHS/HSC organisations

To help you prepare for the transition to combined review, we’re running a series of free, live webinars during December. They are designed for different user groups involved in CTIMPs and will provide an overview of upcoming changes and how they may impact you, depending on your role.

You can see dates available and reserve your place using our online booking system. You will need to register for an account on the Learning Management System.

Participating Research Ethics Committees (RECs)

All RECs authorised to review CTIMPs are now able to review combined applications. Visit our REC directory to search meeting dates.

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