Clinical Research

Clinical Trial Design for Medical Devices

The design of your clinical study determines whether your submission succeeds or fails. A trial with the wrong endpoints, underpowered sample size, or a protocol that FDA will not accept costs far more to fix mid-study than to design correctly from the start.

Design Your Clinical Study
IDE Study Architecture Pivotal & Feasibility Trials Statistical Analysis Plans OPC-Based Study Design

Study Design Strategy

When FDA Requires Clinical Data — and When It Doesn't

Not every 510(k) submission requires clinical data, and not every PMA program requires a randomized controlled trial. FDA's requirement for clinical evidence is driven by the device's classification, the adequacy of bench and performance data to demonstrate substantial equivalence or reasonable assurance of safety and effectiveness, and the device's intended use and patient population. Determining whether clinical data is required — and if so, what type — is a strategic question that shapes the entire development program timeline and budget.

For Class II devices pursuing 510(k) clearance, FDA's de novo and 510(k) guidance documents identify the types of performance data required by device category. Where bench and preclinical data are insufficient to address safety or effectiveness questions, FDA will request clinical data either at the time of submission or, more costly, via an Additional Information request after submission. Identifying this gap during pre-submission strategy development is considerably less expensive than discovering it after a 510(k) submission has been filed.

For Class III PMA devices, the pivotal clinical study is the centerpiece of the submission. FDA's guidance on clinical study design for specific device types, together with a pre-submission meeting strategy, defines the acceptable study design parameters before a single patient is enrolled.

IDE vs. Non-IDE Studies: Regulatory Risk Classification

Before a clinical investigation begins, the sponsor must determine whether the study requires an Investigational Device Exemption (IDE). Under 21 CFR Part 812, studies involving significant risk (SR) devices require an approved IDE application from FDA before the study may begin. Studies involving non-significant risk (NSR) devices proceed under abbreviated IDE requirements — IRB approval is sufficient, but the study must still comply with IDE regulations.

The SR/NSR determination is made by the IRB, but FDA must concur. Misclassifying an SR device as NSR is a clinical protocol violation that can invalidate the study data and create compliance exposure. We prepare SR/NSR justification memoranda with supporting FDA guidance citations so sponsors enter the IRB process with a defensible position.

Statistical Architecture: Endpoints, Power, and the Analysis Plan

The statistical analysis plan (SAP) is the foundational document that determines how study data will be analyzed and interpreted. Primary endpoints must be clinically meaningful, measurable, and pre-specified. Sample size calculations must document power assumptions, clinically meaningful difference, variance estimates, and dropout assumptions. For objective performance criterion (OPC)-based designs — common in cardiovascular, orthopaedic, and neuromodulation PMA programs — the OPC must be established in consultation with FDA and documented in the pre-submission record.

We develop SAPs that are written with the FDA biostatistics reviewer in mind: pre-specified primary and secondary analyses, handling of missing data, subgroup analyses, interim analysis rules where applicable, and multiplicity adjustments. An SAP that leaves analytical decisions to the end of the study is a liability — FDA expects the analysis to follow the pre-specified plan, and deviations require formal justification.

What We Deliver

  • Clinical data strategy memo: when clinical evidence is required and what type
  • SR/NSR determination with supporting justification memorandum
  • Study design document: design type, endpoints, population, controls, duration
  • IDE application or abbreviated IDE documentation package
  • Statistical analysis plan (SAP) including sample size justification
  • OPC/performance goal development with FDA pre-submission support
  • Protocol outline for sponsor or CRO development
  • Pre-submission meeting request and meeting package preparation
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Build a Clinical Program FDA Will Accept

Clinical study design decisions made early in the program determine submission success or failure years later. We bring FDA clinical reviewer expectations into the design process from day one.