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MHRA sets out how it will assess non-clinical data generated outside OECD MAD system

🇬🇧 MHRA · Wed 04 Nov 2026

New guidance explains when UK trial applications relying on non-OECD MAD safety data may be considered, including enhanced assessment in limited circumstances and a programme of test facility inspections.

The Medicines and Healthcare products Regulatory Agency (MHRA) published guidance on 4 November 2026 describing how it will handle clinical trial applications that rely on non-clinical safety data generated outside the OECD Mutual Acceptance of Data (MAD) framework. The agency calls it a patient-centred approach that supports more risk-proportionate clinical research and could widen opportunities for UK patients to join trials.

Data generated within the OECD MAD system, which is based on agreed testing standards and Good Laboratory Practice, remain the expected basis for UK clinical trial applications. The new guidance sets out how the MHRA may consider non-OECD MAD data in individual applications where the available evidence and the circumstances of the intended patient population justify further regulatory consideration.

In making that judgement, the MHRA will weigh the non-clinical evidence against the proposed trial's context. Factors include the participant population, the seriousness of the condition, unmet medical need, and the stage and design of the trial. In limited circumstances the agency may carry out an enhanced non-clinical assessment, which it says could include first-in-human trials in patients with advanced cancers or other serious or life-threatening conditions with significant unmet need. This gives the available evidence additional scientific scrutiny where appropriate.

The MHRA also plans a strategic, risk-based programme of inspections of non-clinical test facilities that are frequently named in UK clinical trial applications. It says the findings will inform future regulatory assessments. The agency stresses that the guidance does not change the standards expected for the quality, safety or integrity of pivotal non-clinical safety data, and that its approach will evolve with regulatory experience, compliance intelligence and inspection outcomes.

Developers planning to use non-OECD MAD data are encouraged to engage with the MHRA early, before submitting a clinical trial application.

What it means for your team

  • Sponsors relying on non-OECD MAD non-clinical data should read the full GOV.UK guidance and plan how to justify the data package in the context of their intended population and trial design.
  • OECD MAD-compliant data remain the expected basis, so non-OECD MAD data should be seen as a case-by-case route, not a general alternative.
  • Early engagement with the MHRA before submission is recommended and may help reduce the risk of queries or delays.
  • Test facilities frequently cited in UK applications may be inspected, so quality teams should monitor the compliance standing of their non-clinical providers.

Official source: MHRA ↗

Article written by VigiEye from the official source (MHRA). AI-assisted; check the source before acting.

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