Quote from Chief Pharmacist on February 4, 2026, 3:44 pm

This question has become increasingly common in the post-Brexit regulatory environment, especially for companies following a UK-first or UK-parallel filing strategy.

The short regulatory answer is that, in most cases, a separate bridging bioequivalence study is not required when the bioequivalence study has been conducted against an EU innovator, provided appropriate scientific justification is submitted.

Following Brexit, the UK MHRA allows the use of an EU-sourced Reference Medicinal Product for UK marketing authorisation applications, as long as equivalence between the EU innovator and the UK reference product can be scientifically demonstrated.

A separate bridging study is generally not required when the EU and UK innovator products are the same in terms of marketing authorisation holder, qualitative and quantitative composition, dosage form, strength, route of administration, and manufacturing site or process. In such cases, both products are considered pharmaceutically equivalent, and the EU innovator may be accepted as a suitable reference through scientific justification.

In practice, MHRA usually expects a comparative assessment rather than an additional clinical study. This includes a comparison of EU and UK SmPCs, confirmation of formulation sameness, reference product batch details, and a clear justification explaining why the EU reference product is representative of the UK reference medicinal product.

However, a bridging study may be required in specific scenarios. These include situations where the EU and UK innovator formulations differ, where manufacturing sites or compositions are not the same, for modified-release or complex dosage forms, for narrow therapeutic index drugs, or where the UK innovator is no longer marketed and equivalence cannot be adequately demonstrated through documentation alone.

From a practical industry perspective, most UK generic applications today successfully rely on bioequivalence studies conducted against EU innovators, supported by a robust scientific justification rather than additional clinical bridging studies.

The key regulatory principle remains unchanged: bioequivalence data must be relevant, scientifically justified, and representative of the product authorised in the UK.

Understanding this distinction helps avoid unnecessary studies, reduces development timelines, and supports efficient UK-first generic filing strategies.