IVDR for Companion Diagnostics: A Practical Guide for Oncology Programmes

IVDR for Companion Diagnostics: A Practical Guide for Oncology Programmes

For oncology drug developers, the EU In Vitro Diagnostic Regulation (IVDR) has changed how a companion diagnostic (CDx) reaches the market. Under the old IVD Directive, most CDx were self-declared by the manufacturer. Under the IVDR, every CDx needs a notified body, a technical documentation assessment for each device and a scientific opinion from a medicines regulator before it can carry a CE mark.

This guide covers what the IVDR requires for companion diagnostics, how the EMA consultation works, where the transition deadlines now sit, what the in-house exemption means for oncology labs, and how to build a realistic EU timeline for a drug and CDx programme. It complements our step-by-step guide to the FDA companion diagnostic approval process. All regulatory facts below were checked against EUR-Lex, the European Commission, the EMA and the MHRA as of October 2026.

Key takeaways

• Companion diagnostics are class C (Annex VIII, Rule 3(f)), and every CDx gets its own notified body technical documentation assessment.
• The notified body must first obtain a scientific opinion from the EMA (mandatory for centrally authorised medicines) or a national authority: 60 days, extendable once by 60.
• Legacy self-declared class C devices can stay on the market until 31 December 2028, but only if the 2025 and 2026 QMS, application and written agreement conditions were met.
• The Commission’s December 2025 simplification proposal would narrow the CDx consultation to novel devices. As of October 2026 it is still a proposal.
• Four EUDAMED modules have been mandatory since 28 May 2026; the performance studies module is not yet live.
• Great Britain accepts IVDR-compliant CE-marked IVDs until 30 June 2030, pending the outcome of an MHRA consultation on indefinite recognition.

IVDR basics: Regulation (EU) 2017/746 and the risk classes

Regulation (EU) 2017/746 replaced the IVD Directive (98/79/EC) and has applied since 26 May 2022. Its biggest structural change is a risk-based classification system with four classes, set out in Annex VIII:

Article 2(7) defines a companion diagnostic as a device that is essential for the safe and effective use of a corresponding medicinal product, to identify, before or during treatment, patients most likely to benefit from it, or patients likely to be at increased risk of serious adverse reactions. Annex VIII, Rule 3(f) places every device “to be used as companion diagnostics” in class C. Many oncology assays would land in class C anyway, because Rule 3(h) covers devices used in the screening, diagnosis or staging of cancer.

Under the Directive, most of these tests sat on no list and needed no notified body at all. That is why the IVDR has hit oncology diagnostics so hard: almost every predictive biomarker assay moved from self-declaration to third-party assessment.

The CDx conformity assessment: notified body plus medicines authority

What the notified body does

For ordinary class C devices, Article 48(7) requires a QMS assessment (Annex IX, Chapters I and III) and a technical documentation assessment for at least one representative device per generic device group. For companion diagnostics the rule is stricter: the notified body must assess the technical documentation of every CDx under Annex IX, Section 5.2, and must consult a medicines authority before issuing the certificate. Manufacturers can instead take the type-examination route (Annex X with Annex XI, Article 48(8)), which carries the same consultation requirement.

The medicines authority consultation

Under Annex IX, Section 5.2, the notified body sends the draft summary of safety and performance and the draft instructions for use to the medicines authority and asks for a scientific opinion on the suitability of the device for the medicinal product concerned. The rules on who is consulted are:

• EMA, mandatory: where the medicine falls exclusively within the scope of the centralised procedure (the Annex to Regulation (EC) No 726/2004). This covers most oncology medicines.
• The authority responsible for the authorisation: where the medicine is already authorised or an application has been submitted.
• National competent authority or EMA: for other medicines.

The consulted authority must give its opinion within 60 days of receiving all necessary documentation, and that period may be extended once by a further 60 days on justified grounds. The notified body must give “due consideration” to the opinion and report its final decision back to the authority. Changes that affect performance, intended use or suitability with the medicine need a follow-up consultation.

EMA’s practical arrangements

The EMA’s companion diagnostics page sets out the procedure. The notified body, not the drug sponsor, submits the consultation, using separate forms for initial and follow-up consultations. EMA’s Q&A on practical arrangements (EMA/619893/2022, last revised in August 2026) asks for a letter of intent at least three months before the expected submission date, allows up to 20 days for registration of the application, and recommends early interaction between the notified body, the device manufacturer and the marketing authorisation holder or applicant. The device manufacturer pays EMA’s fee.

The practical point for pharma: the EMA opinion depends on the drug’s clinical data, so if the CDx manufacturer, the notified body and the drug’s regulatory team are not working to one plan, the consultation becomes the bottleneck. EMA’s FAQ on medicinal product development involving a CDx is worth reading alongside scientific advice plans.

IVDR transition period: the 2022 and 2024 amendments

The IVDR’s transition rules have been amended twice, and the dates in older guidance are now wrong.

Regulation (EU) 2022/112

Regulation (EU) 2022/112 introduced staggered transitions by class for legacy devices that had been self-declared under the Directive but need a notified body under the IVDR: 26 May 2025 for class D, 26 May 2026 for class C and 26 May 2027 for class B and sterile class A. It also deferred most in-house device conditions (see below).

Regulation (EU) 2024/1860

Regulation (EU) 2024/1860, in force since 9 July 2024, pushed the deadlines out again but made the extension conditional. The current Article 110 positions are:

To benefit, a legacy device must also still comply with the Directive, have no significant change in design or intended purpose, present no unacceptable risk, and the manufacturer must have had an IVDR quality management system in place by 26 May 2025. IVDR post-market surveillance, vigilance and registration requirements apply to these devices in place of the Directive’s.

For class C, two dates matter now. The application deadline of 26 May 2026 has passed, and the written agreement deadline of 26 September 2026 has just passed as this guide is published. A legacy CDx whose manufacturer missed either step cannot rely on the extension. The 2024 amendment also added Article 10a (from 10 January 2025): manufacturers must normally give at least six months’ notice before an interruption or discontinuation of supply that could seriously harm patients. The Commission’s transitional provisions page carries the official factsheets.

The proposed revision of the MDR and IVDR

On 16 December 2025 the Commission published a proposal to simplify the rules on medical and in vitro diagnostic devices, COM(2025) 1023 (procedure 2025/0404(COD)). It is a proposal, not law. According to the European Parliament’s Legislative Observatory, the lead SANT committee published its draft report on 30 June 2026 and amendments were tabled in July; no committee vote, Parliament position or Council general approach had been recorded when we checked in October 2026, and a first-reading plenary is indicatively forecast for 14 December 2026.

The proposal’s CDx-relevant changes include:

• clarifying that a CDx may be linked to more than one medicinal product;
• limiting the medicines authority consultation to novel companion diagnostics, and stating that the consulted authority should not repeat the notified body’s assessment;
• removing the requirement to notify performance studies on CDx that use only left-over samples, and removing prior authorisation for studies involving only routine blood draws;
• making the in-house exemption more flexible and extending it to laboratory-developed tests used exclusively in clinical trials;
• replacing fixed five-year certificate validity with periodic, risk-based review by notified bodies.

Plan on the law as it stands. If the proposal is adopted, it will help programmes that reach certification after it applies, but the final text and dates are still open.

The in-house exemption (Article 5(5)) and oncology labs

Many EU oncology centres run their own predictive assays, from IHC protocols to NGS panels. Article 5(5) exempts devices manufactured and used only within a health institution from most IVDR requirements, but not from the Annex I general safety and performance requirements, provided that:

• the devices are not transferred to another legal entity and are not made on an industrial scale;
• manufacture and use occur under an appropriate quality management system;
• the laboratory complies with EN ISO 15189 or applicable national provisions;
• the institution justifies that the target patient group’s needs cannot be met, or not at the appropriate level of performance, by an equivalent device on the market;
• the institution publishes a declaration covering the devices, keeps documentation, reviews clinical experience and takes corrective action where needed.

The dates are staggered. The core exemption applied from 26 May 2022, most conditions from 26 May 2024, and the “no equivalent device on the market” justification in point (d) applies from 31 December 2030, after Regulation 2024/1860 moved it from 26 May 2028.

For oncology, point (d) is the one to watch. Once a CE-marked CDx exists for a biomarker, a hospital lab running an in-house alternative will, from 2030, need to justify why the commercial test does not meet its patients’ needs. For pharma, the exemption is also not a route for pivotal trial assays run by commercial central labs, because those are generally not health institutions under the current text. The Commission’s proposal would extend the exemption to LDTs used exclusively in clinical trials and drop point (d) for IVDs, but that is not yet law.

IVDR notified body capacity and EUDAMED

How many notified bodies, and how long it takes

The Commission’s 20th notified body survey (data to 28 February 2026) counted 19 notified bodies designated under the IVDR, with 3,418 IVDR applications lodged and 2,318 IVDR certificates issued since designation. The pool is still small relative to the legacy devices that must move across before the 2027 to 2029 deadlines.

The survey does not publish an IVDR time-to-certificate figure. Its MDR data is a useful benchmark: from written agreement to a new QMS plus product certificate, 51% of notified bodies reported 13 to 18 months and 31% reported 19 to 24 months. A CDx adds the medicines authority consultation (up to 120 days) plus any clock stops. Planning for 18 to 24 months from application to certificate is prudent, as a planning assumption rather than a published CDx statistic.

EUDAMED

Under the gradual roll-out introduced by Regulation 2024/1860, each EUDAMED module becomes mandatory six months after the Commission publishes a notice that it is functional. Commission Decision (EU) 2025/2371 was published on 27 November 2025, and according to the Commission’s EUDAMED overview four modules have been mandatory since 28 May 2026: actor registration, UDI/device registration, notified bodies and certificates, and market surveillance. The vigilance and post-market surveillance module is in development, and the clinical investigations and performance studies module is still under analysis, with no date given. Until it is live, performance study applications and notifications follow national procedures.

Clinical evidence and performance studies (Article 58 onwards)

A CDx needs a performance evaluation covering scientific validity, analytical performance and clinical performance (Article 56 and Annex XIII). For oncology programmes, clinical performance data usually come from the pivotal drug trial, which is where the IVDR and the Clinical Trials Regulation (EU) No 536/2014 meet.

Article 58(1) sets extra requirements (authorisation by each Member State, ethics review, Annex XIV documentation) for performance studies involving surgically invasive sample-taking for the study, interventional clinical performance studies, or additional invasive procedures or risks. Article 58(2) applies the same requirements to all performance studies involving companion diagnostics, with one exception: CDx studies that use only left-over samples need only be notified to the competent authority. A sponsor based outside the EU needs a legal representative in the Union.

What this means for trial assays:

• Classify the trial assay early. If its result decides who is enrolled or treated, it is usually a CDx performance study under Article 58(2). The Commission’s MDCG 2022-10 Q&A explains how to assess an assay’s medical purpose in a trial.
• Budget time for combined studies. The drug trial goes through CTIS under the CTR; the performance study still goes through national routes. The Commission’s COMBINE programme is working to align them.
• Lock the assay before the pivotal trial, and retain samples with consent for future bridging or label extension work.

For a deeper view of the evidence package, see our guide on how to validate an IO biomarker in a clinical trial.

A practical EU timeline for a drug and CDx programme

The timeline below is a planning framework built from the legal steps above. Durations are indicative and will vary by notified body, assay technology and whether the CDx is novel.

For the commercial side of this, including who owns which milestones, see our article on structuring IVD companion diagnostic co-development between pharma and diagnostics partners.

IVDR companion diagnostics checklist

• Confirm the intended purpose meets the Article 2(7) CDx definition.
• Identify the consulted medicines authority (EMA for centrally authorised drugs).
• Confirm the diagnostic partner’s IVDR notified body has the right scope and capacity.
• Map trial assay use to Article 58 and plan authorisations or notifications per Member State.
• Align the draft IFU and summary of safety and performance with the draft SmPC before MAA submission.
• Diarise the EMA letter of intent at least three months ahead.
• For legacy CDx, confirm the 2026 application and written agreement conditions were met.
• Track COM(2025) 1023, but do not plan on it until it is adopted.

The UK angle in brief

Great Britain and Northern Ireland now differ. In Northern Ireland, the EU IVDR has applied since 26 May 2022. In Great Britain, the MHRA regulates IVDs under the UK Medical Devices Regulations 2002, which are based on the old Directive. Under those rules many tests, including most CDx, are general IVDs that the manufacturer self-certifies for UKCA marking.

According to the MHRA’s guidance, IVDR-compliant CE-marked IVDs can be placed on the GB market until 30 June 2030, and all IVDs must be registered with the MHRA first. The MHRA consulted from 16 February to 10 April 2026 on recognising IVDR- and MDR-compliant devices indefinitely; its timelines page says current arrangements remain in place meanwhile. Check for a government response before finalising UK launch plans. For now, an IVDR-certified CDx is also the most efficient route into GB.

FAQs

What class are companion diagnostics under the IVDR?

Companion diagnostics are class C under Annex VIII, Rule 3(f) of the IVDR. Each one needs a notified body technical documentation assessment and a scientific opinion from the EMA or a national medicines authority before certification.

How long does the EMA take to give its opinion on a companion diagnostic?

Under Annex IX, Section 5.2, the medicines authority must give its opinion within 60 days of receiving all necessary documentation, extendable once by a further 60 days on justified grounds. EMA asks notified bodies for a letter of intent at least three months before submission.

What is the IVDR transition period for legacy class C devices?

Class C devices self-declared under the Directive can be placed on the market until 31 December 2028 if the manufacturer had a QMS by 26 May 2025, applied to a notified body by 26 May 2026 and signed a written agreement by 26 September 2026, and the device has not changed significantly.

Has the EU adopted the MDR and IVDR simplification proposal?

No. The Commission published COM(2025) 1023 on 16 December 2025. As of October 2026 it is still going through the ordinary legislative procedure, with no Parliament position or Council general approach recorded. Plan on the current IVDR.

Can hospital labs keep using in-house tests instead of a CE-marked CDx?

Yes, under Article 5(5), if they meet its conditions, including ISO 15189 compliance and no transfer to another legal entity. From 31 December 2030 they must also justify that no equivalent device on the market meets their patients’ needs.

Discuss IVDR and CDx strategy at ImmunoMark London, 3–4 March 2027

EU regulatory and market access questions for companion diagnostics are part of the Biomarkers & Companion Diagnostics stream at ImmunoMark Summit London. The immuno-oncology and biomarker conference in London runs two parallel streams, Next-Gen IO and Biomarkers & CDx, with keynotes, panels, case studies and pre-arranged 1:1 meetings. London 2026 brought together 300+ attendees from 100+ companies, 70% of them senior decision-makers, and the 2027 edition expects 400+.

Register for ImmunoMark London 2027

Regulatory consultancies and notified-body-ready CDx partners: if your company wants to meet the pharma and biotech teams planning EU companion diagnostic programmes, see the London 2027 sponsorship opportunities.