How long is the FDA De Novo review timeline in 2024?

For a company developing a novel, low-to-moderate risk device, the FDA De Novo pathway is often the appropriate regulatory route when no predicate device exists. While the Medical Device User Fee Amendments (MDUFA V) establish a performance goal for the FDA to make a MDUFA Decision on De Novo requests within 150 review days, this official timeline does not represent the total calendar time a sponsor might realistically expect from submission to final decision. Sponsors planning product launch and financing milestones must understand the distinction between "FDA review days" and total elapsed time. The 150-day clock is not a continuous countdown. It can be paused if the FDA issues a request for additional information (AI) to address deficiencies in the submission. When an AI letter is sent, the review clock stops and only restarts once the sponsor has submitted a complete response. This "time on hold" depends entirely on how long it takes the sponsor to gather the necessary data and formulate a response, which can add weeks or months to the overall timeline. Therefore, a De Novo submission could take significantly longer than 150 calendar days to receive a final classification decision. ### Key Points * **Official MDUFA V Goal:** The FDA's performance goal is to make a decision on De Novo requests within 150 FDA review days. This is a goal, not a guaranteed timeline. * **The "Stop-the-Clock" Mechanism:** The 150-day review clock pauses when the FDA issues an Additional Information (AI) request. The clock only resumes after the sponsor provides a complete response. * **FDA Days vs. Calendar Days:** The total time to a decision is often much longer than 150 calendar days due to the time the submission is on hold pending the sponsor's response to AI requests. * **Submission Quality is Key:** A high-quality, complete, and well-organized submission is the most effective strategy for minimizing the risk of AI requests and keeping the review process on track. * **Early FDA Engagement:** Utilizing the Q-Submission program to align with the FDA on testing plans and data requirements before filing can significantly reduce the likelihood of major deficiencies and delays during the formal review. ## Understanding the 150-Day MDUFA Goal Under the most recent Medical Device User Fee Amendments (MDUFA V), the FDA has set a performance goal to review and act on De Novo classification requests within 150 days. It is crucial for sponsors to understand that this refers to **150 FDA review days**, not 150 consecutive calendar days. This timeline reflects the time the submission is actively under review at the FDA. The primary factor that extends the total calendar time beyond this goal is the issuance of an Additional Information (AI) request, which effectively stops the review clock. A final "MDUFA Decision" can be a granting order, a decline order, or another final action on the submission. ## The "Stop-the-Clock" Mechanism: Additional Information (AI) Requests The most common reason for a De Novo review to extend beyond 150 calendar days is an AI request from the FDA. During the substantive review, if the FDA identifies deficiencies or requires clarification, it will issue an AI letter to the sponsor. Common reasons for an AI request include: * Insufficient or inadequate performance testing (bench, animal, or clinical). * Unclear benefit-risk analysis. * Inadequate information to establish appropriate general and special controls. * Missing administrative or formatting elements required under 21 CFR regulations. When an AI letter is sent, the 150-day review clock is paused. It remains paused until the sponsor submits a complete response addressing all of the FDA's questions. The time it takes a sponsor to prepare this response—which can range from a few weeks to several months depending on the complexity of the request—is not counted as part of the FDA's review time. A thorough and well-prepared initial submission is the best way to avoid a lengthy clock-stop. ## Strategic Considerations and the Role of Q-Submission For novel devices seeking clearance through the De Novo pathway, early and strategic engagement with the FDA is paramount. The Q-Submission program, particularly a Pre-Submission (Pre-Sub), is an invaluable tool for de-risking the formal review process. By submitting a Pre-Sub, sponsors can obtain non-binding feedback from the FDA on key aspects of their planned submission, including: * The proposed clinical or non-clinical testing strategy. * The adequacy of the proposed performance data to support the device's safety and effectiveness. * The proposed general and special controls needed to mitigate risks. Aligning with the FDA on these critical points before submitting the formal De Novo request can significantly reduce the chances of receiving a major AI letter. This proactive approach helps streamline the official review, minimize "stop-the-clock" periods, and increase the predictability of the overall regulatory timeline. While a Q-Submission adds time to the pre-market phase, it often saves a significant amount of time during the formal review. ### Key FDA References * FDA's guidance on the De Novo Classification Process. * FDA's guidance on the Q-Submission Program. * Relevant regulations under 21 CFR Part 860, Subpart D – De Novo Classification Procedures. ### How tools like Cruxi can help Navigating the De Novo pathway requires meticulous organization and a clear presentation of evidence. Tools like Cruxi can help sponsors structure their submission narrative, manage performance data, and systematically build the benefit-risk arguments required by the FDA. By centralizing documentation and aligning the submission with FDA guidance documents, teams can improve the quality of their initial filing and better prepare for the rigorous review process. This article is for general educational purposes only and is not legal, medical, or regulatory advice. For device-specific questions, sponsors should consult qualified experts and consider engaging FDA via the Q-Submission program.