Claiming equivalence under the EU MDR

Sergio Perez, EU MDR consultant, discusses the challenges that manufacturers might face when claiming equivalence.

Claiming equivalence with a device that is already CE marked can help medical device companies save time and money. But scandals with devices including hip replacements and breast implants have shown why the industry needs to pay careful attention when making these claims.

The MDR is being introduced in May 2021 to ensure medical devices sold in the EU have high levels of quality and safety. Every device on the market needs to be CE marked under the new regulation, which introduces sweeping changes to many aspects of the approval process. One way manufacturers can reduce the amount of work involved in achieving a CE mark under the MDR is by claiming equivalence with another product, as it will save them from performing costly clinical studies. 

Compared with the Medical Device Directive (MDD), the MDR requires more substantiated evidence that a product is equivalent, which is harder for manufacturers to achieve. The Medical Device Regulations will require that technical, biological and clinical characteristics are shared when claiming equivalence to another device. So, if you are comparing two devices with the same characteristics, but made from different materials, that won’t cut it. There is therefore a greater need for a robust literature search, gap assessment and there may be a requirement to perform further clinical studies.

Technical characteristics

Technical equivalence mean products should be used under similar conditions of use — there should be no clinically significant differences in the performance and safety of the device. It also includes physicochemical properties, such as surface structure, viscosity and strength. Technical equivalence also includes software — algorithms shall be similar in the device presumed to be equivalent. This is important to remember, as software engineering changes over time and it may be difficult or impractical to recreate an older program.

Biological characteristics

Any material or substances in contact with human tissues or body fluids needs to be certified as biologically safe, in line with EN ISO 10993. However, even though a certified material is being used, the MDR newly states that equivalence requires a similar kind and duration of contact, as well as similar release characteristics of substances, including degradation products and leachables.

Clinical characteristics

Equivalence under the MDR can only be claimed when the device is used for the same clinical condition or purpose and has the same kind of user. This includes similar severity or stage of disease at the same site in the body. The patient must also be in a similar population of age, anatomy and physiology. The new MDR guidance has removed gender and duration of use from this section, making the remaining patient similarities more important and justified.

Issues for the safety, clinical performance and outcome of the product must be taken into consideration because of different user competencies. For example, a device intended for professional use can have a different performance profile and have fewer safety features than a device intended for home use. Manufacturers must do extensive research to ensure that the intended user is like the proposed equivalent medical device.

Demonstrating equivalence

Considerations of equivalence should be based on proper scientific justification and be well documented in the technical file. This means that manufacturers must address the product’s technical, biological and clinical characteristics with a thorough literature search. They should also carry out gap analysis to evaluate any clinically significant difference between their product and the proposed equivalent product.

The MDR expects manufacturers to fully identify and disclose any differences between the two devices that are shown during the analysis, covered in clause 6 clinical data identification. Unfortunately, collating the large amount data from previous clinical investigations to prove equivalence can be very challenging and increase approval time.

The main exception to design differences is if the alterations have been made to address specific safety or performance issues and do not significantly alter the safety and clinical performance of the product. These exceptions allow manufacturers to improve existing products, while maintaining the cost and time benefits of creating an equivalent product.

Claiming equivalence to a competitor’s data is a much trickier tale. In many cases, medical device companies will be unable to claim equivalence and must conduct clinical studies of their own. Working with a skilled MDR consultant can help identify any gaps early, so that there is time to collect the required data before the MDR deadline.

Uses of data from similar devices

The definition of equivalence under the MDR is that the devices are similar to the extent that there would be no clinically significant difference in the safety and clinical performance of the device. However, the MDR defines similar devices as devices having the same or similar intended purposes or a commonality of technology, allowing them to belong to the same generic device group. In cases where equivalence cannot be demonstrated, data from similar devices can become very useful.

Similar devices can ensure that the risk management system is comprehensive and help define the scope of clinical evaluation, to reduce the product’s potential hazards and safety issues. Data from similar devices can also provide input for clinical investigation design or post-market clinical follow-up, help identify relevant clinical outcome parameters and define minimum requirement for a quantified clinical benefit. Additional information from similar devices greatly helps manufacturers during the research and product design stages of development.

Equivalence made easy

To the untrained eye, navigating equivalence under the MDR seems like a minefield. Manufacturers across Europe and further afield are concerned that they will have to spend huge amounts on clinical investigations or they will be unable to continue to market their product in the EU. However, there is already a wealth of experienced MDR professionals able to navigate the regulations on behalf of medical device manufacturers. One option is to work with a qualified freelancer, who can help with all aspects of technical documentation, including whether equivalence can be claimed.