Why your FDA equivalent doesn’t work under MDR

Written by HATEM RABEH, MD, MSc Ing

Your Clinical Evaluation Expert And Partner

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I see this pattern repeatedly. A manufacturer launches a European market strategy based on what worked in the United States. They have FDA 510(k) clearance. They have clinical data from U.S. submissions. They assume this will simplify the MDR process.

It doesn’t.

The confusion comes from the word ‘equivalence.’ FDA uses it one way. MDR defines it another. The two systems are not compatible. Using FDA predicates as MDR equivalents requires understanding the fundamental differences in regulatory logic, evidence requirements, and what each system actually considers comparable.

This post explains what you can and cannot do when you want to reference FDA-cleared devices in your MDR clinical evaluation. Not what people say in webinars. What actually survives a Notified Body review.

The Core Problem: Two Different Equivalence Definitions

Under FDA’s 510(k) pathway, substantial equivalence means your device has the same intended use and similar technological characteristics as a predicate device. If technological characteristics differ, you must show the device is as safe and effective and does not raise different questions of safety and effectiveness.

That’s FDA’s test. It’s device-focused. It’s comparative in design.

MDR equivalence is different. According to MDR Article 61 and MDCG 2020-5, equivalence requires clinical, technical, and biological equivalence. You must demonstrate that your device and the equivalent device have similar clinical performance, safety profiles, and specifications. The equivalence must be based on published literature or other clinical data from the equivalent device.

Here’s the first critical gap: FDA substantial equivalence does not require clinical data demonstrating similar clinical performance. MDR equivalence does.

So when you cite an FDA-cleared device, you are not citing an MDR equivalent. You are citing a device that went through a different evaluation process with different evidence standards.

This doesn’t mean you cannot use it. It means you cannot assume equivalence. You must build it.

What You Can Do: Use FDA Devices as Literature Sources

The FDA-cleared device may have published clinical data. That data can support your clinical evaluation. Not as proof of equivalence, but as part of your literature review and state of the art analysis.

If the FDA device has peer-reviewed publications showing clinical performance, safety outcomes, or long-term data, you can appraise and include that literature. The device being FDA-cleared is irrelevant to the value of the published evidence. What matters is the quality, relevance, and applicability of the clinical data.

This is where manufacturers often miss the opportunity. They focus on the FDA clearance itself instead of mining the literature that may exist around that device.

In your clinical evaluation report, you would reference those studies as part of your evidence base. You would appraise them according to standard critical appraisal methods. You would discuss how that data informs your understanding of safety and performance for devices in the same category.

You are not claiming equivalence. You are using available clinical evidence.

What You Cannot Do: Claim Direct Equivalence Without Clinical Data

You cannot claim that because your device is substantially equivalent to an FDA predicate, it is therefore equivalent under MDR. The logic doesn’t transfer.

Some manufacturers try to argue that if Device A is equivalent to Device B under FDA rules, and Device B has clinical data, then Device A inherits that data by transitivity. This doesn’t work under MDR.

MDCG 2020-5 is explicit. Equivalence must be demonstrated through direct comparison. You must show that your device and the equivalent device are clinically, technically, and biologically similar. A regulatory decision from another jurisdiction does not substitute for that demonstration.

The Notified Body will ask: where is the clinical data showing your device performs like the claimed equivalent device? If you only reference a 510(k) summary, you have not answered that question. The 510(k) summary describes design comparison, not clinical equivalence.

Even if the FDA predicate has clinical data, you still need to demonstrate that your device is equivalent to that predicate according to MDR criteria. That requires technical and biological characterization, side-by-side comparison of specifications, and justification that the clinical data from the predicate is applicable to your device.

This is more work than manufacturers expect. It’s also where most equivalence strategies fail.

When FDA Devices Can Support an Equivalence Strategy

There is a scenario where FDA-cleared devices become useful in building MDR equivalence. It’s not direct, but it’s structured.

Let’s say you identify a CE-marked device that meets MDR equivalence criteria. That device has clinical data supporting its performance and safety. You can demonstrate clinical, technical, and biological equivalence to that CE-marked device.

Now, if that same CE-marked device is also FDA-cleared and has additional published data in U.S. markets, you can use that data to strengthen your equivalence argument. The FDA clearance itself is still irrelevant, but the clinical evidence generated in U.S. use may add post-market data, long-term performance studies, or real-world evidence.

You are layering evidence. Your equivalence is still based on the CE-marked device. The FDA data supplements your understanding of clinical performance.

This works because you have not violated the equivalence logic. You have identified an MDR equivalent and used all available clinical data to support your evaluation.

What Notified Bodies Actually Check

When you reference an FDA device in your clinical evaluation, the Notified Body will check the following:

First, did you confuse FDA substantial equivalence with MDR equivalence? If your equivalence justification relies on 510(k) clearance as proof, the evaluation will be rejected. The Notified Body expects you to demonstrate equivalence according to MDR criteria, not cite another regulator’s decision.

Second, did you provide sufficient clinical data? If the FDA device has no published studies, and you claim equivalence to it, you have not met MDR requirements. Equivalence depends on having clinical data from the equivalent device. If that data doesn’t exist, the device cannot serve as an equivalent.

Third, did you demonstrate technical and biological equivalence? Notified Bodies will examine your device specifications, materials, design features, and intended use. They will compare these to the claimed equivalent device. If there are differences, you must justify why those differences do not affect clinical performance or safety. Referencing FDA clearance does not address this requirement.

Fourth, is the equivalent device CE-marked under MDR or the previous directives? If you claim equivalence to an FDA-only device with no CE mark, the Notified Body may question whether that device would meet European requirements. This creates doubt about the validity of the equivalence claim.

The scrutiny is high. The burden of proof is on you. FDA clearance is not proof.

Practical Steps When You Want to Use FDA Devices

If you have an FDA-cleared device in mind, here’s how to approach it under MDR:

First, identify whether the device is also CE-marked. If yes, use the CE-marked version as your equivalence reference. Appraise the clinical data available for that device. Conduct a technical and biological comparison. Build your equivalence demonstration according to MDCG 2020-5.

Second, search for published literature on the FDA device. This includes clinical studies, real-world evidence, post-market surveillance data, or registry data published in peer-reviewed journals. Appraise and include relevant studies in your literature review. Reference them as part of your state of the art, not as equivalence proof.

Third, do not cite the 510(k) clearance itself as evidence of safety or performance. The clearance is a regulatory decision, not clinical data. Notified Bodies do not accept regulatory decisions from other jurisdictions as clinical evidence.

Fourth, if the FDA device is not CE-marked and has no published clinical data, it is not useful for MDR purposes. You cannot build equivalence on it. You cannot use it as literature. Move on and find another device with better evidence.

This approach avoids common mistakes. It aligns with what Notified Bodies expect. It uses FDA devices appropriately without overreaching.

Why This Misunderstanding Persists

Manufacturers assume that regulatory clearance in one market should ease entry into another. That assumption is rooted in global harmonization efforts, mutual recognition agreements, and the desire for regulatory efficiency.

But MDR and FDA operate on different risk philosophies. FDA’s 510(k) pathway is designed for incremental innovation and market access speed. MDR’s equivalence pathway is designed for evidence-based safety and performance assurance. The two systems prioritize different things.

When you conflate them, you introduce risk into your submission. The Notified Body sees a misunderstanding of MDR requirements. That undermines confidence in the entire clinical evaluation.

The solution is not to ignore FDA devices. It’s to use them correctly. Recognize what FDA clearance represents. Extract the clinical evidence that exists. Apply it within MDR’s framework. Do not shortcut the equivalence demonstration.

What Comes Next in This Series

This was part four in the series on handling FDA comparisons in your MDR clinical evaluation. The next post will address a related but distinct issue: how to handle devices that are cleared in the U.S. but have never entered the European market. These devices create unique challenges for literature searches, state of the art discussions, and PMCF planning.

If you are working on a clinical evaluation that involves FDA predicates, competitor analysis, or cross-border regulatory strategies, these distinctions matter. They determine whether your submission moves forward or stalls in the first review.

The MDR does not accept regulatory shortcuts. It requires evidence. Understanding what counts as evidence and what doesn’t is the foundation of a defensible clinical evaluation.

Peace,
Hatem
Clinical Evaluation Expert for Medical Devices
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