Qualtech, in cooperation with its partner TOTAL Diversity Clinical Trial Management, a US-based full-service Contract Research Organization (CRO), recently hosted a webinar on Medical Device Studies in the United States. Expert speakers Ms. Melynda Geurts and Ms. Tina Bland of TOTAL Diversity shared practical insights on US regulatory pathways, study design considerations, and best practices for subject management and retention.

 

1. US FDA Medical Device Classification and Implications

The US FDA regulatory system is based on around 1,700 generic device types, grouped into 16 specialty panels such as cardiovascular, radiological, and orthopaedic. The FDA then classifies devices into Class I, II, III based on the individual product's risk. Importantly, the device classification determines the applicable regulatory pathway and level of controls, while the study design mainly depends on whether the device is considered "Significant Risk" (SR) or "Non-Significant Risk" (NSR).

Overall, it can be summarized that Investigational Device Exemption (IDE) is required for Significant Risk (SR) studies. On the other hand, Institutional Review Board (IRB)-only may suffice for Non-Significant Risk (NSR) / exempt studies.

Overview of Premarket Pathways by Device Class

Device Class	Typical Premarket Pathway
I	Often 510(k) exempt (not exempt if intended for a use of substantial importance in preventing impairment of health or presents a potential unreasonable risk of illness or injury.
II	510(k) required, sometimes exempt; these are generally lower-risk, well-established products that comply with specific limitations, such as not having a new intended use or fundamental technology change.
III	PMA or reclassification via De Novo

 

2. Regulatory Pathways: IRB vs. IDE Requirements

When it comes to regulatory pathways, one needs to understand the differences between the Institutional Review Board (IRB) and the Investigational Device Exemption (IDE), and when each of them is required. To put simply, Investigational Device Exemption (IDE) allows a device to be shipped lawfully for the purpose of clinical investigations to evaluate its safety and effectiveness.

Typically, studies involving Significant Risk (SR) devices require FDA and Institutional Review Board (IRB) approval. Non-significant risk (NSR) studies; however, only need IRB approval.

When is an IDE Required?

• If it involves a clinical investigation with human subjects.
• When the device is not legally marketed for the particular intended use or used outside its labelling.
• If the study involves a Significant Risk (SR) device.
   

Regulatory Pathways can therefore be summarized as follows:

• Significant Risk: FDA IDE required, IRB approval, informed consent.
• Non-Significant Risk: No FDA IDE required, IRB approval, informed consent (full compliance with 21 CFR 812b requirements).
• Exempt: No FDA IDE required; IRB approval and consent only.

Besides, certain scenarios commonly trigger the IDE requirements, including:

A) First-in-human studies, B) Early feasibility or pivotal trials, C) New indications or expanded device use, and D) Life-sustaining or implantable devices.

 

3. Designing a Medical Device Study in the United States

Successful study design begins with early regulatory alignment. Sponsors must clearly understand their device’s risk classification, as this determines regulatory controls and requirements.

Classification Determines Regulatory Controls

• Class I (Low Risk) → General controls
• Class II (Moderate Risk) → Special controls
• Class III (High Risk) → Premarket Approval (PMA) required

Secondly, it has to be determined whether the device falls into the SR or the NSR category outlined above, as this defines the applicable pathway to be chosen: IDE or IRB. Ultimately, the sponsor proposes SR or NSR, while the IRB determines the classification, which US FDA has the power to potentially override.

If uncertainty exists, our experts highly recommend initiating interactions with US FDA early to ensure alignment and avoid delays.

Align Study Outcomes with Approval Pathway

• 510(k): Demonstrate substantial equivalence to a predicate device
• PMA: Requires robust clinical evidence
• De Novo: For novel devices without a predicate

 

4. Site Section and Sample Size Considerations

The number of sites and subjects must align with the study's purpose (e.g., feasibility, pivotal, or post-market). The FDA's expectations also depend on whether the device is classified significant risk or non-significant risk. Moreover, the design should ensure statistical power, representativeness, and operational feasibility.

How Many Sites Shall be Chosen?

• It's based on enrolment rate per site and desired study duration.
• Investigator experience and patient access.
• Geographic diversity to support generalizability.
• Feasibility assessments for site capacity.

Typical Study Size Benchmark

Study Type	Typical Subjects	Typical Sites
Feasibility / Early Feasibility	10 – 50	2 – 5
Pivotal (Premarket)	150 – 500+	10 – 30
Post-Market / Registry	200 – 2000+	15 – 100+

 

5. Remote Monitoring in Medical Device Studies

While remote monitoring has become increasingly common, it is important to remember that it must still meet the same regulatory expectations as on-site monitoring. Relevant regulations and guidance include: U.S. FDA, 21 CFR Part 812, 21 CFR Part 50, 21 CFR Part 56, 21 CFR Part 11, and ISO 14155:2020.

Components of a Remote Monitoring Strategy

• Risk-based monitoring (RBM) framework
• Centralized data review
• Remote source data verification (SDV)
• Electronic systems access
• Communication and escalation processes

Supporting technology infrastructure often includes electronic data capture (EDC), remote access to electronic health records (EHR), secure document portals, and a clinical trial management system (CTMS).

 

6. Key Takeaways

This webinar provided a practical overview of US regulatory requirements for medical device studies, including FDA classification, IDE vs. IRB pathways, and how risk determination shapes study design and approval strategy. For manufacturers aiming to expand into the US market, strategic regulatory planning and a strong local partner are essential to success. Qualtech and our partner TOTAL Diversity form a powerful alliance you can rely on when navigating medical device studies and the subsequent registration processes with the US FDA.

Contact us today to learn how we can help you to assess your study needs and accelerate your device's market entry into the US market.