Clinical Evaluation Under EU MDR: When Can Equivalence Be Used?

Under the EU Medical Device Regulation (EU)2017/745 (EU MDR), clinical evaluation is a cornerstone of demonstrating that a medical device is safe and performs as intended. But the route to showing sufficient clinical evidence isn’t the same for every device.

Depending on risk class, design history, and available data, manufacturers may rely on clinical investigations, existing clinical data, or under specific conditions, equivalence, to demonstrate clinical safety and performance of a device.

This article explains the main pathways to obtaining clinical / clinically relevant evidence, when equivalence can be applied, and why it has become far more challenging under EU MDR than it was under the old MDD (93/42/EEC) framework.

Routes to Obtaining Sufficient Clinical Evidence

Not every medical device requires new clinical investigations. EU MDR Article 61 provides several ways to demonstrate conformity to the General Safety and Performance Requirements (GSPRs), including:

a) Clinical investigations  

For new, high-risk, or innovative devices, especially Class III and implantable products, a clinical investigation remains essential. It provides direct human data to verify safety and performance, ensuring that evidence aligns with the device’s intended use.

b) Use of existing clinical data (own device or equivalent device)

Devices that are well-established on the market or have robust post-market performance data may rely on existing clinical data, supported by literature reviews, post-market surveillance (PMS) data, or Post-Market Clinical Follow-Up (PMCF) studies.

c) No new clinical data 

In some low-risk cases, no new clinical data are needed if the manufacturer can justify compliance using non-clinical evidence such as:

• Bench testing and verification studies
  
• Biocompatibility testing
  
• Animal studies simulating clinical use

For example, a simple or long-established device like a wheelchair may rely on non-clinical and post-market data rather than new human studies.

However, manufacturers must clearly justify why this data is sufficient to meet GSPRs, a challenge that often attracts scrutiny from notified bodies.

When and How Equivalence Can Be Used

One potential pathway under EU MDR Article 61 is to demonstrate equivalence to another device that already has sufficient clinical data.

Equivalence allows the manufacturer to use clinical data from a comparable device to support its own evaluation, avoiding duplicate studies.

The EU MDR defines three dimensions of equivalence:

1. Technical – similar design, specifications, and principles of operation.
   
2. Biological – same materials in contact with the same tissues or body fluids.
   
3. Clinical – same intended purpose, performance, and safety profile in the same clinical condition.

Manufacturers must demonstrate all three aspects to claim equivalence.

The Challenge of Equivalence Under EU MDR

While equivalence was common practice under the former MDD, EU MDR has made it significantly more difficult to rely on this route.

•  For a manufacturer of implantable devices and class III devices claiming equivalence to an already marketed device not manufactured by them, in addition to the requirements in EU MDR Article 61(4), the manufacturer must have full access to the proposed equivalent device’s technical documentation.
  
• There is a formal contract or agreement between manufacturers confirming data access. Note: For some lower-risk devices (Class I, IIa and IIb), this contractual access is not mandatory to claim equivalency

The equivalence claim is maintained over time, meaning that if the original device changes, it may invalidate the equivalence claim.

In practice, very few competitors will agree to share proprietary data. This makes equivalence feasible only in limited situations, such as when the equivalent device belongs to the same manufacturer or a sister company.

Alternative Approaches When Equivalence Isn’t Possible

If access to another manufacturer’s data isn’t available, there are still other ways to build a robust clinical evaluation:

a) In-house or affiliated device equivalence

If you already have a similar device on the market and full access to its data, equivalence can be demonstrated within your own product family or corporate group.

b) Comparative testing

Manufacturers can purchase competing devices and conduct comparative bench or performance testing. While this provides valuable insights, it doesn’t replace full data access and may still face notified body pushback.

c) Post-market and non-clinical evidence

Regulators increasingly recognise the role of real-world evidence, PMS data, and non-clinical data (e.g. mechanical, animal, or bench testing) as part of a broader clinical evidence package, particularly for lower-risk or well-established technologies.

The Evolving Regulatory Perspective: Article 61 Updates

Regulatory discussions, such as the Team NB proposals and draft revisions to MDCG guidance, are exploring ways to clarify EU MDR Article 61 and make it more proportionate.

Key themes include:

• Narrowing the mandatory scope of clinical data for devices where such evidence may not be appropriate.
  
• Redefining “clinical data” to include real-world evidence, post-market data, and non-clinical studies.
  
• Emphasising clinically relevant non-clinical evidence as a valid component of the overall evaluation.

Example:

Bench testing of a trocar (a surgical puncture instrument) can simulate skin penetration using animal hide. While not clinical in the traditional sense, such testing still provides clinically relevant evidence supporting performance and safety.

These proposals acknowledge that for certain devices, rigorous non-clinical evidence with thorough justification on the approach can sometimes be sufficient to demonstrate compliance, reducing the need for duplicative human data.

Practical Guidance for Manufacturers

• Plan your evidence route early. Decide whether to pursue clinical investigation, equivalence, or non-clinical justification during design and development.
  
• Use the MDCG equivalence templates. These help ensure all technical, biological, and clinical comparisons are structured and auditable.
  
• Leverage existing data. Use PMS and PMCF results to strengthen your justification.
  
• Be realistic about access. If you can’t obtain full technical documentation, build an evidence plan around your own data or comparative testing.
  
• Monitor regulatory updates. Future guidance may expand what counts as “sufficient clinical evidence,” especially for low-risk devices.

The Bottom Line

Equivalence remains a legitimate but increasingly limited route under EU MDR. It works best when manufacturers have access to the data of a related or in-house device.

For most others, the focus should shift toward integrated evidence strategies, combining clinical data, real-world performance information, and non-clinical testing to satisfy regulators.

Ultimately, the goal of any clinical evaluation is the same: to demonstrate that the device performs safely and effectively throughout its lifecycle. The route you take, be it investigation, equivalence, or non-clinical justification must lead to that same outcome.

LFH supports medical device manufacturers in planning and conducting compliant clinical evaluations under EU MDR. From equivalence assessments and gap analyses to PMCF strategy and clinical evidence documentation, our experts help you build credible, regulator-ready submissions tailored to your device classification and market goals.

FAQs – Clinical Evaluation Under EU MDR