Early Feasibility Studies (EFS) let sponsors test high-risk devices in small, first-in-human trials. With FDA’s flexible IDE pathway, EFS enables rapid feedback, iterative design, and smoother transition to pivotal trials—accelerating safe innovation.
Medical device development often follows a phased approach: an Early Feasibility Study (EFS) or first-in-human trial for initial insights, followed by larger pivotal studies to gather definitive evidence. FDA recognizes this model and has established policies to facilitate early feasibility IDE studies. Here’s how sponsors can take advantage and plan their clinical strategy:
An EFS is a limited clinical investigation of a device early in its development, typically:
FDA launched the EFS Program to encourage companies to conduct those first-in-human studies in the U.S., rather than abroad, to benefit U.S. patients and innovation. They even published guidance (“Investigational Device Exemptions for Early Feasibility Studies… including First in Human”) which outlines regulatory flexibility the FDA might allow for EFS. For instance, FDA might accept less preclinical data up front for an EFS IDE as long as the potential risks are justified and mitigated, acknowledging that exhaustive testing could be impractical when the device design may change.
When designing an EFS under an IDE, focus on key questions:
Examples: A new cardiac implant EFS might look at successful deployment rate and any serious complications within 30 days. A new diagnostic EFS might look at whether the test results can be obtained and are interpretable, not yet whether it improves outcomes. Because by nature you have limited data, ensure rigorous monitoring and enforce stopping rules – you may pause the study if a certain number of serious adverse events occur.
A pivotal IDE trial is typically the larger, confirmatory study that will support a marketing application (like a PMA). It usually has:
Insights from the EFS can greatly inform the pivotal trial design. For example, if the EFS indicated that a certain patient subgroup had better outcomes, you might refine inclusion criteria for pivotal. Or you might learn which adverse events to specifically watch for (and implement additional precautions or power the study to evaluate those events).
Regulatory-wise, you will need to submit an IDE amendment or a new IDE for the pivotal study protocol, depending on scope. Often, sponsors can continue under the same IDE number by submitting a “Protocol Amendment” to expand into a larger study, especially if no significant gap between studies. FDA will review the new protocol (again aiming for 30 days). If the device underwent changes after EFS, ensure all new bench/animal testing supporting those changes is included.
If your pivotal trial is underway and showing benefit, FDA has mechanisms like Continued Access IDE (sometimes called an Extended Investigation) to allow access to the device for patients while the PMA is under review, but that’s after pivotal. For EFS to pivotal, one concept is the “adaptive” trial approach – some sponsors design the feasibility and pivotal as phases of one continuous trial (with a pause to analyze the feasibility phase). FDA can be open to creative designs, but you’d detail this in the IDE.
Suppose you have a novel neurostimulation device. You might do an EFS in 10 patients to tweak the implantation technique and device programming. Based on those results, you improve the device and then launch a 100-patient randomized pivotal trial. FDA’s EFS guidance would have allowed a bit of flexibility in requiring exhaustive reliability testing prior to EFS, understanding that the design might change; but before the pivotal, you’d then complete full bench testing on the final design. In your IDE submissions, you’d justify that approach and FDA would consider the totality of info.
Engage FDA early if you plan to utilize the EFS pathway. FDA may offer a Pre-Sub meeting specifically to discuss your EFS plan – they might advise on what preclinical data is minimally necessary to start human testing. The EFS guidance encourages an interactive approach, and FDA often assigns experienced reviewers for EFS IDEs to work more hands-on with sponsors.
In conclusion, not every device needs an EFS, but for high-risk, breakthrough technologies, it can be an ideal approach. It aligns with FDA’s push for “speeding innovation to patients” by starting with small trials. When done correctly, EFS data pave the way for a well-founded pivotal trial, increasing the likelihood that your pivotal will succeed (since major uncertainties were ironed out in EFS). Always keep the end goal in mind: design your feasibility studies so that they inform the pivotal questions, and design pivotal studies that meet FDA’s evidence requirements for approval. By thoughtfully planning the entire clinical investigation pathway under IDE—from first-in-human to final pivotal—sponsors can accelerate development while still ensuring patient safety and regulatory compliance.
