UK Clinical Trials Regulations 2026: Your 12-Month Results Clock Now Collides With Your Publication Plan

The Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025 (SI 2025/538) came into force on 28 April 2026 and rewrote regulation 25 of the 2004 Regulations [1]. For clinical trials of investigational medicinal products (CTIMPs), the sponsor must:

• Register the trial in a public registry by the earlier of first recruitment or 90 days after approval (reg 25(1)).
• Publish a results summary within 12 months of the end of the trial (reg 25(2)).
• Offer a lay summary of the results to “relevant persons”, such as participants and their legal representatives, in the same period (reg 25(2)).

Failing to meet these duties without an approved deferral is an offence [1].

Source: Pubrica illustration based on SI 2025/538 and HRA guidance [1, 2].

The HRA measures the 12 months from the global end of trial, not from the end of UK recruitment, last patient last visit or database lock [2]. For a multinational study, the UK deadline therefore depends on when the last site anywhere closes. For example, if UK sites close in late 2026 but the last overseas site closes in March 2027, the UK results are due by March 2028, not late 2027. Record the formal end-of-trial date in the trial master file and calculate the deadline from it.

Trials already running on 28 April 2026 follow transitional rules [3]:

Phase 1 trials receive an automatic deferral if the sponsor registers the required minimum information by the deadline [3]. An old-rules trial that missed 27 July is out of compliance now. Register it and document the corrective action.

Source: Pubrica illustration based on SI 2025/538 and the transitional arrangements [1, 3].

The UK allows registration up to 90 days after approval, provided recruitment has not started. ICMJE journals require registration “at or before the time of first patient consent for enrollment” as a condition of considering the paper [4]. In practice the two coincide only if you register before recruitment begins. Register at approval and you satisfy both.

Usually not. ICMJE does not treat results posted in a qualifying registry as prior publication “if results are limited to a brief structured abstract or tables” [4]. The ISRCTN results format matches that carve-out. It has four sections only: participant flow, baseline characteristics, outcome measures and adverse events [5]. Two practical consequences follow:

• Keep the registry summary tabular. Discussion, interpretation and new figures belong in the paper.
• A journal article alone does not meet the UK duty, so the registry summary must exist even if the paper is published first [5].

ICMJE journals also require a data-sharing statement in trial reports [4]. Draft it alongside the registry tables so the two say the same thing.

The regulation requires a summary “written in a manner that is understandable to laypersons” [1]. It is a separate deliverable with its own drafting, review and distribution steps. Assign it to a named medical writer and have it checked for accuracy by the trial statistician. Test it with patient representatives before release. Plan how it reaches “relevant persons” (by post, through the site, or by a link given at consent), because the duty is to offer it, not just to post it.

Deferrals of up to 30 months are available, and waivers only in exceptional cases [1]. A deferral moves the posting date; it does not move your database lock, analysis or manuscript. Keep drafting on the normal timetable so the deferred posting is ready on time.

Work back from the legal deadline. The months below are Pubrica planning targets, not legal requirements.

The map separates the two outputs. The registry summary and lay summary finish on a fixed timetable, and the manuscript proceeds through peer review on its own.

Source: Pubrica illustration. The registry summary does not wait for journal acceptance.

1. The deadline is counted from the UK end of trial instead of the global end.
2. The registry summary waits for journal acceptance.
3. A trial was registered after first consent, which is UK-compliant but fails ICMJE.
4. The trial is listed in two registries, but results are posted in only one. The HRA expects results in each registry where the trial is registered [2].
5. Nobody owns the lay summary, so it is written in month 11 and never tested.

If your trial ends after 28 April 2026, send us your global end-of-trial date and target journal. Pubrica’s medical writers will return a back-planned schedule for registry tables, lay summary and manuscript, and can draft all three. Explore Pubrica’s publication support.