A Research Ethics Committee has flagged readability concerns on the German ICF for a Phase III oncology trial. The Combined Review process at MHRA has come back with comments on the investigator brochure submitted in May 2026. A site activation in Poland is held up because the protocol amendment translation arrived after the local REC submission window closed.
These situations share one cause. Clinical trial translation got scoped as a delivery task rather than as part of the trial’s regulatory and ethics workstream. Clinical trial translation is the work of producing every patient-facing and sponsor-facing document a multi-regional trial requires, under Regulation (EU) No 536/2014, the Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025, ICH E6(R3), and ICH E8(R1).
This guide is for the head of clinical operations, clinical trial manager, or regulatory affairs lead at a pharma sponsor or CRO running EU and UK trials. It gives you the document type matrix, the ICF treatment, the linguistic validation methodology, the EU and UK regulatory workflow side by side, and a vendor evaluation checklist that lifts into a supplier RFP. For the deeper read on quality methodology, see the AdHoc cluster piece on medical translation quality assurance, and for an overview of how we structure medical translation work for life sciences, see our service page.
TL;DR
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What EU and UK clinical trial translation requires
Clinical trial translation sits under four overlapping regulatory frameworks. Regulation (EU) No 536/2014 (the EU CTR) governs trials in the EU and EEA. The UK Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025 govern trials in Great Britain. ICH E6(R3) sets the global Good Clinical Practice standard. ICH E8(R1) covers general considerations for clinical studies. Translation obligations live across all four, and the practical effect is that any participant-facing document and any document submitted to a regulator or ethics committee must appear in the official language of the relevant jurisdiction, translated by qualified medical translators, with back-translation and reviewer approval before use.
The legal anchors: EU CTR and UK CTR
The EU CTR replaced Directive 2001/20/EC on 31 January 2022. CTIS, the Clinical Trials Information System, became the single submission entry point on 31 January 2023, and the transition period for legacy trials closed on 31 January 2025. Every EU clinical trial application now goes through CTIS. The UK ran on the older Medicines for Human Use (Clinical Trials) Regulations 2004, which originated from the same EU Directive, until the 2025 amendment regulations brought the UK regime into broad alignment with the EU CTR while keeping UK-specific simplifications. Notable UK additions: a codified Combined Review process for MHRA and the Research Ethics Committee, a notifiable trials route for lower-risk studies, and a mandatory public registry registration with 12-month summary publication.
ICH E6(R3) and the global GCP baseline
ICH E6(R3), the current Good Clinical Practice guideline, was adopted in January 2025 and became effective globally in July 2025. The UK formally adopted it on 28 April 2026 alongside the new clinical trials regulations. For translation, the implications are concrete. Translations must be performed by qualified medical translators. Back-translation and clinical expert review are mandatory for participant-facing materials. All translated participant-facing documents must be approved by the Research Ethics Committee before use. Sponsors must maintain documentation of translation versions and translator qualifications. An LSP that cannot produce that audit record is non-compliant by default.
Which documents need translation
Clinical trial document scope splits into two streams: patient-facing documents reviewed by Research Ethics Committees and Institutional Review Boards, and sponsor-facing documents reviewed by national regulators. Different reviewers, different QA standards, different turnaround pressures. Buyers who treat the two streams as one workstream end up underspending on patient-facing review and overspending on sponsor-facing turnaround.
| Document | Review path | Primary reviewer | Translation requirement |
|---|---|---|---|
| Informed consent form (ICF) | Patient-facing | REC / IRB | Forward + back translation; Certificate of Translation Accuracy |
| Patient information sheet | Patient-facing | REC / IRB | Plain language; back translation for high-risk studies |
| Assent form (paediatric) | Patient-facing | REC / IRB | Age-appropriate language; cognitive debriefing recommended |
| Recruitment materials | Patient-facing | REC / IRB | REC-approved before public use; in-layout review for artwork |
| Patient diary, ePRO, eCOA | Patient-facing | REC / IRB | Linguistic validation per ISPOR PGP; eCOA platform integration |
| Trial protocol | Sponsor-facing | MHRA / NCA via CTIS | Translation if regulator language differs from sponsor’s working language |
| Investigator brochure | Sponsor-facing | MHRA / NCA via CTIS | Submitted to regulator; site staff need access in working language |
| IMPD (Investigational Medicinal Product Dossier) | Sponsor-facing | MHRA / NCA via CTIS | Quality, non-clinical, and clinical sections; often English-only for CTIS |
| Clinical study report (CSR) | Sponsor-facing | MHRA / NCA / EMA | Post-trial; lay summary translation required under EU CTR |
| Plain Language Summary | Public-facing | EMA via CTIS | Within 12 months of trial end; all relevant EU languages |
| Substantial modification documents | Both paths | REC + regulator | Fast turnaround; version-controlled re-translation of affected sections only |
Patient-facing documents and the ethics review path
Patient-facing documents are reviewed by Research Ethics Committees (the EU terminology) or Institutional Review Boards (the US terminology). The ethics path is more conservative than the regulatory path. Translations must arrive REC-ready: forward translation plus back translation, Certificate of Translation Accuracy from a qualified medical translator, and version control aligned with the protocol. Most ethics committees will not approve a participant-facing document until the back translation has been reviewed and signed off.
Sponsor-facing documents and the regulator path
Sponsor-facing documents go to the national competent authority (or to MHRA in the UK) through CTIS in the EU or via the Combined Review portal in the UK. The IMPD and the investigator brochure are often submitted in English even where the trial runs in non-English-speaking member states, depending on regulator practice. The protocol and CSR fall under the same English-only convention for many regulators, with translated extracts requested during inspection or audit. The lay summary of the CSR, by contrast, must appear in every relevant member state language under EU CTR Article 37.
For medical device trials, the underlying regime is Regulation (EU) 2017/745 not the CTR, and the relevant cluster reference is MDR translation requirements. The post-approval product information that follows a successful clinical trial – SmPC, package leaflet, labelling under EMA QRD templates – sits in its own regulatory framework and is covered in package leaflet translation.
ICF translation: the highest-scrutiny document
The informed consent form is the document with the highest regulatory and ethical scrutiny in a clinical trial. ICH E6(R3), FDA 21 CFR 50.20, and OHRP 45 CFR 46.116 all converge on the same principle: the participant must understand the ICF in a language they can read. The translation must therefore be plain language in the target language, not a literal carry-over of the source. Most ethics committees require both a forward translation and a back translation, plus a Certificate of Translation Accuracy from the LSP signed by qualified medical translators.
The back-translation step uses two independent translators. The first produces the forward translation. A second translator, blind to the original source, translates the target text back into the source language. A project manager compares the back translation to the source and flags any divergence in meaning. Disagreements are resolved before submission. This adds time and cost, and is non-negotiable for ICFs in any trial of meaningful risk class.
The other operational reality is version control. Substantial modifications to the protocol almost always trigger an ICF update. Each update needs the full forward-and-back translation cycle for each participating language, and the new version must be approved by every local REC before sites can switch participants over. An LSP that cannot produce versioned ICF translations with full audit trail will create a documentation gap that surfaces in the next inspection.
Linguistic validation: separate from translation
Linguistic validation is a distinct workflow from translation, used for patient-reported outcomes (PROs), clinical outcome assessments (COAs), and any psychometric instrument where the meaning of an item to a patient must be preserved across languages. The methodology follows the ISPOR Principles of Good Practice (Wild et al., Value in Health 2005;8(2):94–104). Sponsors who buy linguistic validation as if it were translation get translation-grade output and regulatory comments at the next ethics review.
| Step | Activity | Purpose |
|---|---|---|
| 1 | Forward translation | Two independent translators produce forward translations into the target language. |
| 2 | Reconciliation | A third linguist reconciles the two forward translations into a single agreed version. |
| 3 | Back translation | An independent translator (blind to the source) translates the target version back into the source language. |
| 4 | Back translation review | The project team compares the back translation with the original source and flags divergences. |
| 5 | Harmonisation | Versions across multiple target languages are reviewed for consistency in the way each item is interpreted. |
| 6 | Cognitive debriefing | Interviews with 5–8 members of the target patient population to confirm the items are understood as intended. |
| 7 | Review of cognitive debriefing | Findings from the debriefing are reviewed and the target version is adjusted where needed. |
| 8 | Proofreading | Final linguistic and format review of the validated version. |
| 9 | Final report | Documentation of the full methodology, every translator used, and every decision made. Submitted to the sponsor and to the REC if requested. |
When to use linguistic validation
Linguistic validation applies to validated PRO and COA instruments where a regulator or a publication will rely on the patient’s responses as measurement data. Examples: the EQ-5D, the SF-36, condition-specific quality-of-life scales, electronic diaries that score symptom severity. For a generic ICF or a recruitment flyer, full linguistic validation is overkill; a translation plus back-translation cycle is the standard. The LSP should be able to advise on which documents need which methodology, with named terminology management across both pathways.
CTIS and the UK CTR: two parallel workflows
Multi-regional sponsors run EU and UK trials as parallel workstreams. CTIS is the EU submission portal. The Combined Review portal is the UK equivalent. The two regimes are now broadly aligned in scope (both reflect ICH E6(R3) and ICH E8(R1)) but they operate on separate timelines, with separate documentation requirements, and they update on different schedules.
| Element | EU (CTR 536/2014) | UK (CTR 2025, SI 2025/538) |
|---|---|---|
| Submission portal | CTIS (single EU portal) | Combined Review (MHRA + REC, single application) |
| Came into force | 31 January 2022, full transition 31 January 2025 | 28 April 2026 |
| Language scope (patient-facing) | Official language(s) of each participating member state | English |
| Language scope (sponsor-facing) | English commonly accepted by regulators; extracts may be requested in member state language | English (MHRA working language) |
| Plain Language Summary | Required within 12 months of trial end, in relevant languages | Required within 12 months under new regulations; UK English |
| Public registry | EU Clinical Trials Register (EU CTR) | Mandatory public registry registration under new regulations |
| Lower-risk routes | Standard CTIS application for all trials | “Notifiable trials” route with three lower-risk conditions |
| Terminology | “Subjects” or “participants” | “Participants” (terminology updated from “subjects”) |
| Average set-up time | Varies by member state | Around 122 days (HRA/MHRA Combined Review) |
Operational implications for translation
Run the EU and UK workstreams in parallel from kick-off, not sequentially. CTIS submission triggers the participating member state language matrix; the UK Combined Review submission is English-only but the translation back-catalogue (participant-facing documents from earlier UK trials) still needs maintenance against ICH E6(R3) version control.
Patient diaries and PROs integrated into an eCOA platform (Clario, Signant Health, IQVIA Clinical Outcomes, CRF Health) often need API delivery of validated language versions on platform timelines that do not match the regulator’s. SmartConnect is the integration anchor for that handoff. For the broader software-translation discipline that sits behind these eCOA platforms – UI string handling, IEC 62366-1 usability validation, AI Act technical documentation for AI-enabled trial software – see medical software translation. SmartDesk carries the per-project audit trail across both regimes.
Clinical trial translation vendor evaluation checklist
A clinical-trial-ready translation supplier holds ISO 17100 and ISO 18587 certifications, demonstrates ICH E6(R3) and ISPOR PGP fluency, runs back-translation as a documented workflow with named translator roles, produces a Certificate of Translation Accuracy as a standard deliverable, supports eCOA provider integration, and handles fast-turnaround amendments. The checklist below lifts directly into a supplier RFP.
| Criterion | Why it matters for clinical trial work | What to ask in the RFP |
|---|---|---|
| ISO 17100 | Process foundation for human translation | Please attach your current ISO 17100 certificate and certification body. |
| ISO 18587 | Required when MTPE is used | Do you hold ISO 18587 for any post-edited MT workflows? Please attach the certificate. |
| ICH E6(R3) awareness | Current global GCP standard | Describe how your QMS reflects ICH E6(R3) requirements on translator qualifications, version control, and audit-trail documentation. |
| Back-translation workflow | Required by most RECs for ICFs | Walk us through your back-translation process: who does the forward, who does the back, how disagreements are resolved, what audit record is produced. |
| Certificate of Translation Accuracy | REC submission deliverable | Confirm you produce a Certificate of Translation Accuracy as a standard deliverable for ICF and patient-facing materials. |
| ISPOR PGP linguistic validation | Required for PROs and COAs | Describe your linguistic validation pipeline against the nine steps of the ISPOR Principles of Good Practice. |
| REC and IRB submission experience | Direct evidence of ethics-pathway fluency | Provide three examples of REC or IRB submissions where your translations went through review without remediation. |
| eCOA provider integration | Clario, Signant Health, IQVIA, CRF Health integration | Describe your integration approach with eCOA platforms and any API or connector you operate. |
| Amendment turnaround | Substantial modifications recur and the timeline is tight | What is your standard turnaround for a protocol amendment affecting ICFs across a 6-language matrix? |
| Per-project audit trail | ICH E6(R3) requires version and qualification documentation | What per-project audit records do you produce, and for how long do you retain them? |
| ISO 27001 | Information security for trial data | Please confirm ISO 27001 certification and attach evidence. |
| In-layout review for recruitment | Posters, cards, leaflets need final-layout review | Can in-country reviewers edit translated recruitment materials in final layout via your platform? |
AdHoc holds current ISO 17100 and ISO 18587 certifications, with the certificates hosted on the AdHoc site for direct verification. SmartDesk carries the per-project audit trail that ICH E6(R3) version control and REC inspection demand. SmartConnect supports API integration with eCOA platforms and CTMS, and SmartEdit lets in-country reviewers edit translated recruitment materials in final layout.
For the deeper read on the QA stack across all medical translation work, see medical translation quality assurance. Communication of trial results to healthcare professionals after publication – KOL slide decks built from the CSR, congress materials, medical education content – sits under the industry promotional codes rather than under the CTR or CTIS framework, and is covered in HCP content translation.
Frequently asked questions
What is the EU CTR for translation?
Regulation (EU) No 536/2014, the EU Clinical Trials Regulation, governs clinical trials of medicinal products in the EU and EEA. It requires every patient-facing document to appear in the official language(s) of each participating member state. Submissions go through CTIS, the Clinical Trials Information System, which has been the single EU portal since 31 January 2023. The transition period for legacy trials closed on 31 January 2025.
Does an ICF always need back-translation?
Yes for any trial of meaningful risk class. Most Research Ethics Committees and IRBs require a forward translation plus back translation, with a Certificate of Translation Accuracy from a qualified medical translator. ICH E6(R3) makes this expectation explicit. The back-translation step uses two independent translators: one for the forward, one (blind to the source) for the back, with a project manager comparing the two.
What changed in UK clinical trials regulation in April 2026?
The Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025 came into force on 28 April 2026. The biggest UK clinical trials regulatory change in twenty years. The Combined Review process for MHRA and the Research Ethics Committee is now codified in law. A “notifiable trials” route handles lower-risk studies. Terminology shifted from “subjects” to “participants.” Public registry registration and 12-month summary publication are now mandatory.
How is linguistic validation different from translation?
Linguistic validation is a nine-step methodology under the ISPOR Principles of Good Practice (Wild et al., 2005), used for PROs and COAs where patient understanding of each item must be preserved across languages. It includes forward translation, reconciliation, back translation, harmonisation, and cognitive debriefing with members of the target patient population. Translation alone covers steps 1–3 and is the right tool for ICFs and recruitment materials, but not for validated patient-reported measures.
Speak with our localisation team
If your current translation supplier cannot answer the checklist questions with documented evidence, a structured supplier review is the next step. Speak with our localisation team about how AdHoc handles ICF, protocol, PRO, and clinical study report translation for pharma sponsors and CROs across the EU and the UK.
Sources
- EUR-Lex, Regulation (EU) No 536/2014 of 16 April 2014 on clinical trials on medicinal products for human use. https://eur-lex.europa.eu/eli/reg/2014/536/oj. Accessed 14 May 2026.
- European Commission, Clinical trials – Regulation EU No 536/2014. https://health.ec.europa.eu/medicinal-products/clinical-trials/clinical-trials-regulation-eu-no-5362014_en. Accessed 14 May 2026.
- The Medicines for Human Use (Clinical Trials) (Amendment) Regulations 2025, Statutory Instrument 2025/538. https://www.legislation.gov.uk/uksi/2025/538.
- Health Research Authority, Clinical trials regulations reform. https://www.hra.nhs.uk/planning-and-improving-research/policies-standards-legislation/clinical-trials-investigational-medicinal-products-ctimps/clinical-trial-regulations-reform/
- ICH E6(R3) Good Clinical Practice (adopted 6 January 2025; effective globally July 2025; UK effective 28 April 2026).
- ICH E8(R1) General Considerations for Clinical Studies.
- Wild D, Grove A, Martin M, et al. Principles of good practice for the translation and cultural adaptation process for patient-reported outcomes (PRO) measures: report of the ISPOR Task Force for Translation and Cultural Adaptation. Value in Health. 2005;8(2):94–104. https://www.valueinhealthjournal.com/article/S1098-3015(10)60252-5/fulltext
- FDA 21 CFR 50.20 and 21 CFR 50.27, Informed consent of human subjects.
- OHRP, Common Rule 45 CFR 46.116 and 45 CFR 46.117.
- ISO 17100:2015, Translation services — Requirements for translation services.
- ISO 18587:2017, Translation services — Post-editing of machine translation output — Requirements.