Equivalent Device

Within the Clinical Evaluation Plan (CEP), if the strategy involves comparing the device under evaluation with one or more legally marketed medical devices (i.e., “equivalent devices”) and leveraging their clinical data to support the safety and performance claims of the new device, a dedicated chapter is essential to rigorously and comprehensively substantiate this “equivalence.” The core task of this chapter is to clearly and systematically demonstrate, in accordance with regulatory requirements (such as EU MDR Article 61(3) and Annex XIV Part A Section 3, with reference to guidance documents like MDCG 2020-5), that no clinically significant differences exist between the device under evaluation and the chosen equivalent device(s) in terms of their clinical, technical, and biological characteristics.

Selection Criteria for Equivalent Devices

Before embarking on a detailed comparison, it is imperative to first articulate the rationale and criteria for selecting specific devices as equivalent. The chosen equivalent device(s) should be products legally marketed in the EU (typically bearing a CE mark). Their selection should not be based merely on superficial similarity but must withstand meticulous comparison across three key dimensions:

1. Clinical Equivalence: The devices must be used for the same clinical condition (including similar disease state and severity), for the same intended purpose (including similar therapeutic or diagnostic effects), in similar target populations (considering aspects like age, anatomy, health status), and at similar sites of use and with similar application methods.
2. Technical Equivalence: The devices must utilize similar designs and technical specifications (e.g., similar operating principles, key performance parameters, deployment methods, and materials and designs of critical components analogous to the device under evaluation), be used under similar conditions of use, and possess similar software algorithms (if applicable).
3. Biological Equivalence: The devices must use the same or highly similar materials in contact with human tissues, and the nature and duration of this contact with the body must also be similar.

Systematically Demonstrating Equivalence

The demonstration of equivalence is a systematic and highly detailed comparative process, not a simple listing. You need to outline this process in the CEP, with the plan to present the full detailed comparative data and analysis in the Clinical Evaluation Report (CER).

The core activity is a feature-by-feature comparison. This means juxtaposing the device under evaluation with each selected equivalent device across all relevant clinical, technical, and biological characteristics. This comparison should be extensive, covering areas such as:

• Clinical Characteristics: A detailed comparison of every aspect of the intended use, the scope of indications, precise definitions of target patient populations, characteristics of the target disease or condition, specific anatomical sites of use, and even differences in the wording of contraindications, warnings, and precautions.
• Technical Characteristics: An in-depth analysis of design features (e.g., specific geometric shapes, energy output parameters, software versions, etc.), similarities and differences in the mechanism of action or operating principle, key performance specifications (such as dimensional ranges, mechanical strength, delivery system compatibility), sterilization methods and sterile barrier systems, and whether they are designated for single use.
• Biological Characteristics: A clear listing of all material components that come into direct or indirect contact with the human body, an assessment of the biocompatibility data for these materials, and a comparison of the mode and intended duration of contact with human tissues.

Identification and Analysis of Differences

When conducting a meticulous feature-by-feature comparison, it is almost inevitable that some differences will be found between the device under evaluation and the equivalent device(s). All such differences must be transparently identified.

Once differences are identified, an in-depth scientific analysis and justification for each difference to prove that it does not have a clinically significant negative impact on the safety and/or clinical performance of the device must be conducted. Such an analysis requires:

• A clear description of the nature and extent of the difference.
• An explanation, based on scientific principles, engineering assessments, standard requirements, published literature, or specific preclinical studies (such as bench testing, animal studies) of why this difference will not lead to different clinical outcomes (e.g., in efficacy, complication rates, ease of use).
• If the difference involves materials, an assessment of potential impacts on biocompatibility, chemical properties, physical properties, etc.
• If the difference involves design or performance specifications, an assessment of its impact on the device’s ability to perform as intended in the anticipated clinical scenario.

Planning and Presenting the Equivalence Argument in the CEP

In this chapter of the Clinical Evaluation Plan (CEP), you need to clearly articulate the plan and methodology for demonstrating equivalence.

It should begin by explicitly stating which specific, legally marketed device(s) are intended for the equivalence demonstration and briefly outline the primary reasons for their selection.

Next, provide an overview of how the detailed comparison of clinical, technical, and biological characteristics will be conducted. You can mention the planned scope of comparative parameters. The emphasis should be on describing how differences will be systematically identified, and how their clinical significance will be assessed and justified.

The CEP should indicate the data sources required to support the equivalence demonstration. This may include:

• Manufacturer’s internal completed or planned preclinical studies (e.g., bench tests, simulated use tests, animal studies, especially those directly comparing the performance of the device under evaluation against the equivalent device(s)).
• Systematic retrieval and analysis of published scientific literature to obtain information on the characteristics, performance, and safety of the equivalent device(s), as well as the clinical impact of certain technical or material differences.
• Adherence to relevant international standards and guidelines.
• Planned retrieval and analysis of post-market surveillance data, adverse event reports, and clinical study data for the equivalent device(s) (if available).

This chapter should set a clear path for how the demonstrated equivalence will be used in the subsequent Clinical Evaluation Report (CER) to support the clinical safety and performance of the device under evaluation. For example, it should state how clinical data from the equivalent device(s) will be integrated and appraised in the CER.

Tthe demonstration of equivalence is a key area of scrutiny by regulatory authorities. The entire process must be transparent, rigorous, scientific, and fully compliant with relevant regulatory guidance (such as MDCG 2020-5). Any claim of equivalence must be substantiated by robust evidence, and the analysis of differences must be convincing.