The demonstration of equivalence is the route by which a manufacturer can rely on the clinical data of an existing device to demonstrate the clinical conformity of its own device. Under the Directive, this route was broad and lightly formalised. Under the MDR, Article 61.5 has considerably tightened its conditions.
Many manufacturers discover, during the assessment of their file, that the demonstration of equivalence they had planned is not feasible. This is one of the main causes of delay in MDR certifications.
The three cumulative criteria of Article 61.5
Article 61.5 requires that the device and the equivalent device be similar across three dimensions, each of which must be documented in a specific way.
Technical equivalence. The two devices are of similar design, used under the same or similar conditions, and have similar performance characteristics and specifications. Any existing differences must not significantly affect clinical safety and performance.
Biological equivalence. The two devices use the same materials or substances in contact with the same human tissues or body fluids. Different materials may nonetheless be considered equivalent if the available data demonstrate that they have no impact on biocompatibility and performance.
Clinical equivalence. The two devices are used in the same clinical setting, for the same medical purpose (diagnosis, treatment, prevention), in a patient population presenting the same medical condition, at the same anatomical site, and by users with the same profile.
The three criteria are cumulative. If one of them is not satisfied, the demonstration of equivalence does not hold — even if the other two are rigorously documented.
The constraint that makes equivalence nearly impossible with a competitor
Article 61.5 adds a requirement that changes everything: if the equivalent device belongs to another manufacturer, the manufacturer invoking equivalence must have “sufficient access” to the data relating to that device to support its claims of equivalence. The MDCG 2020-5 guidance specifies that this access must be guaranteed by a contract between the two manufacturers.
In practice, obtaining contractual access to a competitor’s technical data — design data, verification and validation data, manufacturing data — is in almost all cases impossible. No company shares its confidential technical data with a competitor.
When the demonstration of equivalence remains feasible
Two situations make it realistic to use the demonstration of equivalence.
With a device from the same manufacturer. If the manufacturer has itself placed an earlier device on the market whose data are available in its own archives, it can rely on these data. This is the most common situation: a next-generation device that evolves from an existing platform.
Within the framework of a formalised partnership agreement. If two manufacturers have concluded a collaboration or licensing agreement that includes reciprocal contractual access to technical data, equivalence with the partner device is documentable. This situation remains rare but exists in certain contexts of joint ventures or shared development.