What Are Clinical Trials of Medical Devices?
Clinical trials of medical devices are structured scientific processes involving human participants to confirm the safety, effectiveness, and performance of a device under real clinical conditions. According to MDR 2017/745, they are termed “clinical investigations” and are an integral part of the clinical evaluation required to obtain CE marking. This requirement especially applies to innovative devices and those in higher-risk classes.
Unlike pharmaceutical trials, medical device investigations often focus not only on safety and efficacy, but also on usability, procedural performance, interaction with the user, and device behavior in actual medical settings. This makes study design particularly dependent on the intended purpose of the device, the target population, and the clinical context in which the device is used.
For IVDs, the equivalent concept is a performance study. These studies are used to demonstrate analytical and clinical performance and to confirm that the device delivers results that are accurate, reliable, and clinically meaningful.
Why Are Clinical Trials Required?
Demonstrating safety and effectiveness based on clinical data is a core requirement of MDR certification. These data form the basis not only for market approval but also for post-market surveillance (PMS) and PMCF. Clinical investigations also support the technical documentation and clinical evaluation, impacting PSUR reports.
Clinical trials are required when existing data are insufficient to demonstrate conformity with the applicable General Safety and Performance Requirements. This is particularly relevant for devices that are novel, implantable, high-risk, or based on technologies for which equivalence cannot be adequately demonstrated.
From a regulatory perspective, a clinical investigation provides evidence that the device achieves its intended purpose, that the benefit-risk profile is acceptable, and that the product can be used safely under normal conditions of use. From a business perspective, it reduces the risk of objections from notified bodies and helps prevent delays in market access.
Types of Clinical Investigations for Medical Devices
The type of study depends on the nature of the device, its stage of development, the applicable regulation, and the evidence gap that needs to be addressed. Not every device requires the same type of clinical investigation, and study design should always be proportionate to the risk profile and regulatory objective.
- Efficacy and safety investigations – studies designed to confirm whether the device performs as intended and whether its use is associated with an acceptable level of risk.
- Feasibility studies – early-stage investigations planned on the basis of a feasibility analysis of patients, sites, operational capabilities, and resource availability.
- IVD performance studies – investigations conducted in line with IVD performance study requirements, focusing on parameters such as sensitivity, specificity, predictive values, and clinical relevance of test results.
- PMCF studies – post-market clinical follow-up investigations intended to confirm long-term safety and performance after the device has already been placed on the market.
In practice, manufacturers may need more than one type of study during the lifecycle of the same product. For example, an early feasibility study may be followed by a pivotal clinical investigation and later complemented by PMCF activities.
Roles of Sponsor, Investigator, and CRO
Clear allocation of roles and responsibilities is essential for the lawful and efficient conduct of a clinical investigation. Although several entities may be involved, ultimate responsibility cannot be treated as a purely contractual issue. It must be reflected in governance, documentation, and oversight.
The sponsor is responsible for designing, funding, conducting, and overseeing the clinical investigation—typically the manufacturer. The investigator leads the study at the site and ensures patient safety. The Contract Research Organization (CRO) is a third party the sponsor may delegate tasks to—such as monitoring, audits, and data management—under ISO 14155 documentation.
Even when operational tasks are outsourced, the sponsor remains accountable for ensuring compliance with MDR, IVDR, ISO 14155, ethics requirements, and applicable national procedures. This is why delegation models should always be supported by clear contracts, oversight plans, and traceable quality management processes.
Planning a Clinical Investigation
Strong clinical evidence starts with strong planning. A poorly designed investigation may produce data that are difficult to interpret, insufficient for regulatory purposes, or impossible to defend during notified body review.
Planning begins with the protocol, including inclusion/exclusion criteria, endpoints, statistical analysis strategy, and timeline. The study must comply with clinical investigation design principles, including endpoint definitions, population criteria, and statistical methodology.
At this stage, manufacturers should also define the regulatory objective of the study, identify the evidence gap it is intended to close, assess operational feasibility, and ensure consistency between the protocol, risk management documentation, clinical evaluation strategy, and intended use claims.
A well-planned clinical investigation should also anticipate likely operational challenges such as recruitment delays, protocol deviations, missing data, or the need for amendments. Building these considerations into the study design from the beginning significantly improves execution quality.
Study Registration and EUDAMED
Regulatory submission and registration are not merely administrative steps. They are part of the legal framework governing when and how a clinical investigation may begin.
Every clinical investigation must be registered in EUDAMED and submitted to the national competent authority (URPL in Poland). Required documents include the protocol, investigator’s brochure, risk management plan, informed consent forms, and liability insurance. The study may only commence after ethics committee approval and absence of objections from the authority.
Depending on the Member State and the type of study, local procedural requirements may also apply. For this reason, manufacturers should not treat EUDAMED registration as a standalone action but as part of a broader regulatory submission strategy.
Site Selection and Audit
The quality of study sites has a direct influence on recruitment, protocol compliance, data quality, and subject safety. Site selection should therefore be based on more than availability alone.
Site selection depends on team experience, patient availability, and GCP compliance. A qualification audit must precede site activation, evaluating infrastructure, staff, documentation systems, and ISO 14155 compliance. Selection must follow site requirements.
In practice, site qualification should also assess the site’s experience with similar indications, procedural burden, staff turnover, expected enrollment pace, and ability to work within the sponsor’s data and monitoring framework. Choosing the wrong site can compromise timelines and data integrity from the very beginning of the investigation.
Investigator Qualifications
The competence of the investigator is one of the fundamental conditions for lawful and credible study conduct. Even a strong protocol may fail if the site team does not have the right clinical and operational capabilities.
Investigators must have appropriate professional qualifications and current GCP training. Training documentation should be retained by the sponsor and verified before trial initiation.
In addition to formal qualifications, the sponsor should assess whether the investigator has sufficient experience in the relevant therapeutic area, the ability to manage study procedures in compliance with the protocol, and adequate time and resources to perform investigator duties properly.
Clinical Investigation Conduct
The conduct phase is where the study design is tested in real-world conditions. At this stage, protocol quality alone is not enough. Execution discipline becomes critical.
This includes patient recruitment, site visits, protocol adherence, and data management using EDC systems. Data integrity, subject protection, and adverse event analysis are monitored by the sponsor and CRO. Monitoring is a key component of quality oversight, aligned with GCP, MDR, and ISO 14155.
Proper study conduct also requires control over source documentation, timely query resolution, deviation management, device accountability, and continuous communication between sponsor, CRO, and site teams. Weaknesses in any of these areas may reduce the evidentiary value of the study.
Incident Reporting and Corrective Actions
Serious incidents and safety signals must be managed within clearly defined timelines and procedures. This is both a regulatory requirement and a core element of subject protection.
In the event of a serious incident (SAE/SUSAR), the sponsor must report it to authorities within 7 days (MDR Article 80) and implement CAPA, which may require protocol or ICF updates.
Beyond formal reporting, the sponsor must assess root cause, evaluate the effect on the benefit-risk profile, determine whether additional risk control measures are needed, and document all corrective and preventive actions in a traceable way. Safety management should be embedded in the broader quality and risk management system, not treated as a separate reactive task.
Statistical Analysis
Clinical evidence is only as strong as the way it is analyzed. Statistical planning must therefore begin before recruitment starts, not after data have already been collected.
Clinical data must be analyzed per a pre-defined statistical analysis plan (SAP). Analysis sets like FAS, PPS, and SAF must be selected, and missing data addressed per ISO 14155 and MDR requirements. Statistical accuracy impacts data interpretability.
The statistical methodology should be aligned with study objectives, endpoints, risk profile, and anticipated data limitations. Sponsors should ensure that assumptions, handling of protocol deviations, subgroup analyses, and treatment of incomplete data are all defined in advance and remain consistent with the protocol and regulatory expectations.
Study Documentation
Documentation is one of the most visible indicators of study quality during audits, inspections, and notified body review. Incomplete or inconsistent records can undermine otherwise valuable clinical data.
Required documents include the protocol, informed consent form (ICF), case report form (CRF), investigator’s brochure, monitoring lists, visit reports, adverse event logs, and the final study report. Proper medical writing is critical to meet MDR, GCP, and ISO 14155 standards.
Documentation should be internally consistent, version-controlled, traceable, and suitable for inspection. It should also clearly reflect protocol amendments, safety decisions, deviations, monitoring outcomes, and the rationale for key study decisions made during the investigation.
Results Reporting and CIR
The value of a study depends not only on how it is conducted, but also on how its results are documented and interpreted. Reporting must therefore be complete, transparent, and scientifically justified.
Upon study completion, the sponsor prepares the Clinical Investigation Report (CIR), detailing methods, results, adverse events, and conclusions. This is submitted to EUDAMED and the competent authority. A high-quality clinical investigation report influences notified body review outcomes.
The CIR should clearly explain whether the study objectives were met, how protocol deviations affected interpretability, what safety conclusions can be drawn, and how the data support the overall clinical evaluation. Weak or overly generic reporting often leads to questions during regulatory review.
Ethical Requirements and Informed Consent
Ethics is not a standalone formality. It is a core framework that shapes how the investigation is designed, reviewed, and conducted throughout its lifecycle.
Each study must be ethics committee-approved, and subjects must sign informed consent. The process must comply with MDR and the Declaration of Helsinki. Participants may withdraw at any time without giving reasons.
Informed consent should be understandable, complete, and appropriate for the participant population. The sponsor must ensure that consent is not treated as a one-time signature event, but as an ongoing process of communication and protection of participant autonomy.
Link with PMS and PMCF
Clinical investigations should not be planned in isolation from the post-market phase. Under MDR, clinical evidence generation is a lifecycle process, not a one-time pre-market exercise.
Clinical investigation outcomes support PMS and PMCF as defined in MDR Annex XIV. Lack of integration leads to rejection of the clinical evaluation.
In practice, the results of pre-market and post-market studies should feed directly into PMS plans, PMCF strategies, risk management updates, and periodic regulatory reporting. If these elements are disconnected, the overall clinical evidence package may appear fragmented and unconvincing.
How to strengthen the clinical evidence package for MDR and IVDR submissions
A strong study alone is not always enough to secure a smooth regulatory pathway. What often makes the difference is whether the clinical investigation is integrated into a broader evidence strategy that is coherent, traceable, and aligned with regulatory expectations.
Connect the study with clinical evaluation
Clinical investigation data should be planned and reported in a way that directly supports the clinical evaluation and answers the questions raised by the benefit-risk assessment.
Align the protocol with risk management
Study objectives, endpoints, and safety monitoring should reflect the identified hazards, residual risks, and clinical claims associated with the device.
Plan evidence generation across the full product lifecycle
Manufacturers should treat pre-market studies, PMS, PMCF, PSUR inputs, and risk management updates as connected parts of one evidence system rather than separate documents prepared for different teams.
This integrated approach increases the credibility of the submission and reduces the likelihood of deficiencies during review by competent authorities or notified bodies.
Common mistakes in medical device clinical trials
Many problems in clinical investigations do not result from a lack of effort, but from strategic weaknesses introduced at the planning stage. These weaknesses often become visible only later, when the study is already underway or when the dossier is under review.
Starting the study without a clear regulatory objective
If the sponsor cannot clearly explain what evidence gap the study is meant to close, the investigation may generate data that are difficult to use in the conformity assessment process.
Overestimating site feasibility
Recruitment assumptions that are not supported by realistic feasibility analysis often lead to delays, under-enrollment, and protocol amendments.
Insufficient control of documentation and deviations
Even well-run studies may lose evidentiary value if protocol deviations, missing data, or documentation inconsistencies are not managed properly.
Weak integration with PMS, PMCF, and clinical evaluation
Study data should reinforce the overall clinical evidence package. When they remain disconnected from other regulatory documents, the submission becomes less coherent.
How Pure Clinical Supports Clinical Investigations
Pure Clinical offers end-to-end support for clinical investigations in line with MDR, ISO 14155, and GCP. Our approach combines regulatory knowledge, operational execution, and documentation discipline to help manufacturers build clinical evidence that is both scientifically robust and regulatorily defensible.
- Protocol and EUDAMED documentation development,
- Feasibility analysis and site auditing,
- Monitoring, data management, SAE/SUSAR reporting,
- Preparation of final documentation and CIR,
- Integration of results with PMS and PMCF.
Our team combines CRO expertise, operational know-how, and regulatory insight to support manufacturers in delivering the clinical evidence required by notified bodies.
FAQ
Are clinical trials mandatory for every medical device?
What is the difference between a clinical investigation and a performance study?
When should a manufacturer start planning a clinical investigation?
Planning should begin as early as possible, ideally when the regulatory strategy, intended purpose, and evidence gaps are first being defined. Delaying study planning often leads to protocol changes, documentation inconsistencies, or difficulties aligning the investigation with risk management and clinical evaluation requirements.
Is ethics committee approval always required?
Yes, if the study involves human subjects or human-derived samples in a way that falls under the applicable legal framework, ethics review is required. The study may only begin after the relevant ethics committee has issued a favorable opinion and any competent authority requirements have been fulfilled.
Does every clinical investigation need to be registered in EUDAMED?
Clinical investigations under MDR and relevant performance studies under IVDR must be handled in accordance with the applicable EU registration and submission rules. In practice, manufacturers should treat EUDAMED-related obligations as part of the broader regulatory submission process and verify any additional national requirements that may apply.