An early feasibility study (EFS), a traditional feasibility study, and a pivotal study are three successive stages of clinical evidence for a medical device. The EFS is early, limited, and iterative: small cohort, initial safety and device functionality, design may change. Traditional feasibility confirms the near-final design with preliminary safety and effectiveness data. The pivotal study is the definitive, powered study supporting the marketing application. The three are a typical progression, not a mandatory checklist.
Typical patterns; the FDA aligns the actual evidence plan with each sponsor in a Pre-Submission. General information, not regulatory advice.
Early feasibility study: a limited early clinical study of a device early in development, typically in a small number of subjects, assessing initial clinical safety and device functionality; the design does not need to be final. Traditional feasibility study: a limited clinical study confirming the device's design and operating principles, capturing preliminary safety and effectiveness data in a larger cohort than an EFS, typically with a near-final device. Pivotal study: the definitive clinical study designed to demonstrate safety and effectiveness for the intended use, the evidence the marketing application (PMA, 510(k), De Novo, or HDE) rests on, conducted with a finalized device. Sources: FDA EFS program page; FDA IDE guidance.
Purpose: EFS assesses initial clinical safety and device functionality in a small cohort; traditional feasibility confirms design and operating principles with preliminary safety and effectiveness data; the pivotal study generates the definitive safety-and-effectiveness evidence for the marketing application. Typical size: EFS is small (the FDA sets no fixed number, the cohort is sized to the questions); traditional feasibility is larger than an EFS but still limited; the pivotal study is the largest, sized and powered to support the marketing claim. Design finality: EFS, not final and may be modified; traditional feasibility, near-final; pivotal, finalized, testing the to-be-marketed device. Evidence bar: EFS, enough to justify a small risk-mitigated first clinical use; traditional feasibility, preliminary safety and effectiveness; pivotal, the full evidence package for the marketing application. Questions answered: EFS, is it safe enough to proceed and does the device function in people; traditional feasibility, does the design hold up and what do early effectiveness signals look like; pivotal, is the device safe and effective for its intended use. IDE context: EFS, IDE aligned via Pre-Sub with a first-30-day-cycle approval target; traditional feasibility, IDE via the standard feasibility path; pivotal, the definitive IDE study. What comes next: EFS leads to device iteration, then traditional feasibility or pivotal planning; traditional feasibility leads to pivotal study design and execution; the pivotal study leads to the marketing application. Sources: FDA EFS program page; FDA EFS IDE guidance; EFS 10-year retrospective.
Iteration is the point of the EFS: it is the only stage where the FDA explicitly expects the device to change afterward, so its data are most valuable when they sharpen the design before the expensive stages. The evidence bar rises at each stage: enough for a small mitigated-risk first use, then preliminary safety and effectiveness, then the definitive package, with timelines, budgets, and complexity following that curve. The Pre-Sub sets the plan, not the template: whether a program needs all three stages is aligned with the FDA in a Pre-Submission. Geography follows the question: run the EFS in the US when early, iterative FDA interaction is the priority; run first-in-human in Latin America when speed and enrollment are, engineered from day one to come home under 21 CFR 812.28.
Sometimes. The three stages are a typical progression, not a regulatory checklist. Whether a program needs a traditional feasibility study between the EFS and the pivotal stage, or can move toward pivotal planning on the strength of EFS data and a stable design, is aligned with the FDA through a Pre-Submission, not decided unilaterally. EFS data feed whatever comes next: the FDA's program page frames EFS clinical experience as informing device modifications before the traditional feasibility and pivotal stages.
1. Device iteration: clinical experience informs modifications before later stages. 2. Later-stage study design: EFS data shape the questions, endpoints, and sizing of the traditional feasibility and pivotal studies. 3. The IDE evidence record: EFS results become part of the evidence package the FDA reviews. 4. A US pathway from outside the US: data generated abroad can support the US program when engineered from day one under 21 CFR 812.28 (ISO 14155 conduct, independent ethics review, validatable data).
bioaccess has no US hospital site network. In the US it offers FDA strategy and Pre-Submission/EFS-IDE planning from Miami, and its affiliated site Amavita Research in Miami participates in cardiovascular studies when the device and study fit. Its proven execution footprint is first-in-human and early feasibility studies across 19 Latin American and Caribbean countries.
An EFS is the FDA's early, limited, iterative study: a small cohort, initial clinical safety and device functionality, and a design that may change afterward. A traditional feasibility study comes later, when the device is further along: it confirms the near-final design and operating principles and captures preliminary safety and effectiveness data in a larger, still-limited cohort. Both are conducted under an IDE; the EFS is defined by its early timing and iterative intent.
A pivotal study is the definitive, adequately powered study that generates the safety-and-effectiveness evidence a marketing application (such as a PMA) rests on. Whether one is required, and how large it must be, depends on the pathway and the device, and is aligned with the FDA through the Pre-Submission and IDE process rather than decided unilaterally.
Sometimes. The three stages are a typical progression, not a regulatory checklist. Whether a program needs a traditional feasibility study between the EFS and the pivotal stage, or can move toward pivotal planning on the strength of EFS data and a stable design, is a question to align on with the FDA through a Pre-Submission. It is not a decision to make unilaterally.
Yes, and that is the point of the staging. The FDA's EFS program explicitly contemplates device modifications informed by clinical experience before the traditional feasibility and pivotal stages. By the pivotal stage, the device should be finalized: the pivotal study tests the to-be-marketed device.
The FDA sets no fixed enrollment number for an EFS: the cohort is small and sized to the questions the study must answer. A traditional feasibility study typically enrolls more subjects than an EFS while remaining limited. A pivotal study is the largest of the three, sized and powered to support the marketing claim. Actual numbers depend on the device, the questions, and FDA alignment in the Pre-Sub.
EFS data inform device modifications, shape the design of the traditional feasibility and pivotal studies that follow, and become part of the IDE evidence record. Data generated outside the United States can support the U.S. program when the study is engineered from day one under 21 CFR 812.28: ISO 14155 conduct, independent ethics review, and data the FDA can validate.
bioaccess® has no U.S. hospital site network. From the U.S. side it offers FDA strategy and Pre-Submission/EFS-IDE planning from Miami, and its affiliated site Amavita Research in Miami participates in cardiovascular studies when the device and study fit. Its proven execution footprint is first-in-human and early feasibility studies across 19 Latin American and Caribbean countries. Sponsors get an honest recommendation on which geography their program needs, not a one-geography sales pitch.
Related: FDA EFS program guide · What is an early feasibility study? · US vs Latin America first-in-human · Early feasibility studies in Latin America · FDA acceptance of OUS data · First-in-human CRO · US execution · Pre-Sub for an early feasibility study