Equivalence in medical device law refers to the justified comparison of a device under evaluation with a product already available on the market. Clinical data from the comparator product can only be incorporated into one’s own clinical evaluation if technical, biological, and clinical characteristics support transferability without clinically significant differences.
Three Dimensions of Comparison
The technical dimension encompasses aspects such as design, conditions of use, performance characteristics, and specifications. Biological equivalence concerns patient-contacting parts, specifically materials as well as the type and duration of contact. Clinical characteristics focus on the intended purpose, severity and stage of the disease, body site, user, and relevant performance parameters.
No dimension may be evaluated in isolation. A product with a similar measurement function may be clinically unsuitable despite comparable technology if it is intended for a different patient group. Conversely, an identical indication is insufficient if a different material raises a new biological question. The justification must therefore disclose the differences and explain why they have no clinically relevant impact.
Distinction from Bioequivalence
The existing glossary term bioequivalence belongs to medicinal product law and refers to the comparability of the bioavailability of an active substance. Equivalence under the MDR is not a pharmacokinetic proof, but rather a product-related assessment of technology, biology, and clinical use.
Furthermore, “similar” does not mean “identical.” The MDR guideline requires similar conditions of use, but specifies the same materials for the biological dimension and similar algorithms for software. Previous leeway to accept deviating materials via special exceptions is not continued under the MDR. Material deviations, in particular, must therefore be examined as a potential source of a clinically relevant difference.
Access to Comparative Data
The quality of an equivalence claim does not depend solely on a tabular comparison. For a comparator product, the manufacturer requires sufficient information regarding technical specifications, materials, clinical application, and the data upon which they rely. Without robust access to this information, gaps remain that cannot necessarily be closed by literature alone.
The clinical evaluation should link the search strategy, the comparison matrix, and the conclusion. If a difference is identified, it must be decided whether it needs to be addressed through additional non-clinical data, a clinical investigation, or another source of evidence. Equivalence is thus a limited bridge between data, rather than the wholesale adoption of another product’s market history.
Comparability is not demonstrated by a product name or the same generic product group. It requires a structured comparison of characteristics and available data sources. Particularly in the case of multiple product variants, it must be recorded which variant supports the comparison and whether changes to design, coating, sterilization, or software limit transferability.
The equivalence analysis is also to be distinguished from the assessment of the state of the art. The state of the art describes which safety and performance standards apply to comparable products. An equivalent product can provide clinical data if the requirements of the three dimensions are met; a merely comparable market product does not automatically provide this transferability.
This has an important consequence for the clinical evaluation: the equivalence claim requires its own verifiable conclusion. It is not enough for the comparison table to show predominantly matches. The evaluation must explain for each remaining difference whether it can be clinically relevant and which data support this assessment. If differences are merely labeled as “minor” without examining the impact on safety or performance, the evidence is incomplete.
In the case of software, functional logic is also critical. A similar user interface does not prove equivalence if algorithms can generate different medically relevant results. The guideline explicitly lists similar algorithms as part of the technical comparison dimension. Consequently, the investigation focuses not only on the visible range of functions but on the processing decisive for the intended purpose.
Significance for Clinical Trials
For the planning of clinical investigations, a viable equivalence analysis can clarify which open residual question should be answered by new data. If, for example, access to material data or evidence of the actual conditions of use of the comparator product is lacking, the need for a study cannot be reduced by a mere claim of similarity. Furthermore, trial sites and investigators require a precise description of the investigational product so that the collected endpoints align with the intended purpose.
Full-service CROs like Mediconomics provide support in creating comparison matrices, identifying clinical data through literature, planning product-related trials, and preparing the equivalence argumentation for clinical evaluation in a traceable manner.
Frequently Asked Questions (FAQ)
Is the same intended purpose sufficient for equivalence?
No. Additionally, technical, biological, and clinical properties must be compared such that no clinically significant differences remain.
Can a different contact material be accepted via equivalence?
The MDR guideline requires the same material composition for the biological dimension; a deviating material cannot be justified via the former exceptions.
Must the comparator product be CE-marked?
The clinical evaluation must primarily demonstrate suitable, accessible, and transferable data. The specific regulatory classification of the comparator product is part of the respective assessment.
Regulatory References
- Regulation (EU) 2017/745 (MDR) — regulates the clinical evaluation of medical devices.
- MDCG 2020-5, Clinical Evaluation — Equivalence — describes the three dimensions of comparison.
- MDCG 2020-6, Guidance on sufficient clinical evidence — explains the classification of clinical evidence.
- MDCG 2021-24 Rev. 1, Guidance on classification — refers to clinical evaluation and clinical investigation.