The European regulatory framework for medical devices has undergone a significant transformation with the transition from the Directives (MDD/AIMDD) to the European Union Medical Device Regulation (EU MDR 2017/745). This shift has introduced more stringent requirements, especially in demonstrating the equivalence of medical devices.
The regulation requires the demonstration of equivalence to be more transparent and supported by more evidence. Furthermore, the process of establishing equivalence necessitates careful preparation and comprehensive documentation due to the MDR’s unique criteria and enhanced scrutiny.
Understanding the Equivalence
Equivalence means proving that a new device is as safe and effective as an already existing device in terms of its intended use, design, principles of operation and clinical performance. According to the MDR (Annex XIV, Part A), technical, biological and clinical characteristics must be considered for proving equivalence. The criteria for assessing these three characteristics, discussed in the MDCG 2020-5 guidelines highlights the differences between MDD and MDR.
Technical characteristics
The MDD states that the subject device and its equivalent device must be used under the same conditions of use, the MDR only requires similar conditions of use. If there’s no expected significant difference in safety and performance, the conditions of use are considered similar.
The Medical Device Regulation (MDR) specifically states that software algorithms must be similar between the subject device and its equivalent device unlike under the MDD. The functional principle, the clinical performance and intended purpose of the software algorithm, are considered when demonstrating the equivalence of a software algorithm.
Biological characteristics
Both the MDD and MDR requires the use of the same materials or substances that comes into contact with the same type of human tissue or body fluids. Exceptions can be accepted for devices in contact with intact skin and minor components of devices, as outlined in the MDD. In such cases the results of risk analysis may in several situations permit the usage of similar materials considering the role and nature of the similar material. According to the MDR, it must exhibit similar release characteristics of compounds, such as leachable and degradation products, as the supposed equivalent device, and it must be used for similar kind and duration of contact.
The MDR imposes additional requirements, stating that equivalence must be demonstrated by using the same substances in medical devices composed of substances or combinations of substances intended for introduction into the human body, where they are absorbed or locally dispersed.
These devices are not medicinal products, but they must meet the requirements in Annex I of Directive 2001/83/EC17 for conformity assessment. This includes evaluating how they are absorbed, distributed, metabolized, and excreted, as well as their local tolerance, toxicity, interactions with other devices, medicines, or substances, and potential adverse reactions. These factors must also be considered when proving equivalence under the MDR.
For ancillary medicinal substance, MDR mandates “the same materials or substances in contact with the same human tissues or body fluids” for both the subject device and its equivalent device. This is inclusive of any coatings or excipients it may feature, as it could potentially impact the functionality of the device.
Clinical characteristics
The MDR requires that the device is used by the same type of user, whether it’s a healthcare professional or a layperson. When assessing equivalence between the subject device and its equivalent device, manufacturers must consider whether the intended user’s skills or knowledge could affect the safety, performance and clinical outcomes. For example, A blood glucose monitor for hospital use may be very accurate, provide real-time data to doctors, and need regular calibration. In contrast, a home-use monitor is simpler, easier to use, and designed for occasional self-testing by patients, with basic safety features but not as precise as the hospital version.
While the MDD clearly states that the medical devices to be compared must be used for the same medical indication, gender and duration of use, the MDR describes this in a less strict way, requiring “the same clinical condition of the patient or for the same purpose”. Both the MDD and MDR require that devices address a similar severity and stage of disease and demonstrate similar critical performance characteristics.
Conclusion
The transition from MDD to EU MDR has introduced more rigorous and detailed requirements for demonstrating the equivalence of medical devices. The MDR places a stronger emphasis on comprehensive evidence, including technical, biological clinical characteristics, while also demanding stricter documentation and justification for equivalence claims. As the MDR continues to shape the regulatory landscape, manufacturers will need to adapt their processes and systems to meet these new challenges, ensuring that they can demonstrate the safety and performance of their devices in line with the higher standards set by the regulation.
Author: Dr Shrinidhi Ballal (Jr. Consultant)