How long does the FDA De Novo review process take in 2024?

## How Long Does the FDA De Novo Review Process Take in 2024? While the FDA has a performance goal to make a decision on a De Novo classification request within 150 review days, sponsors of novel medical devices should anticipate that the total calendar time from submission to final decision is often significantly longer. This discrepancy is primarily due to the FDA's "review clock" mechanism, which can be paused during the review cycle. Understanding how this review clock works is critical for accurate project planning, especially for innovative devices like a new therapeutic wearable or an AI-powered diagnostic tool. The 150-day target represents the time the FDA is actively reviewing the submission. If the agency requires additional information to complete its assessment, it issues a request that stops the clock, and the total timeline extends by the amount of time the sponsor takes to prepare and submit a complete response. ### Key Points * **150-Day Performance Goal:** The FDA's goal is to review De Novo requests within 150 "FDA Days," which does not equate to 150 calendar days. * **The Review Clock:** The review clock measures the time the submission is actively under review by the FDA. It begins when the submission is accepted and stops if the FDA issues a Request for Additional Information (AI). * **Impact of AI Requests:** An AI request pauses the review clock. The time a sponsor spends gathering data, performing new analyses, and preparing a response does not count toward the 150-day goal. * **Total Elapsed Time:** Because of potential clock stops, the total calendar time from initial submission to a final decision can extend for many months beyond the 150-day target. * **Minimizing Delays:** A comprehensive, well-organized initial submission that proactively addresses potential questions is the most effective strategy to minimize the likelihood of lengthy review clock pauses. * **Role of Q-Submission:** Leveraging the Q-Submission program allows sponsors to gain alignment with the FDA on key topics *before* submitting the De Novo request, which can significantly de-risk the formal review process. ### Understanding the De Novo Review Clock The concept of the review clock is central to managing timeline expectations for a De Novo submission. The process is governed by performance goals agreed upon under the Medical Device User Fee Amendments (MDUFA). **"FDA Days" vs. "Calendar Days"** The 150-day goal refers to the cumulative number of days the FDA is actively working on the file. This is different from the total calendar time that passes. 1. **Clock Starts:** The review clock begins once the FDA accepts the De Novo submission for substantive review. 2. **Clock Stops:** If the FDA review team identifies gaps or requires clarification on any aspect of the submission—such as clinical data, performance testing, or the proposed Special Controls—they will issue a Request for Additional Information (AI). The moment the AI request is sent to the sponsor, the review clock stops. 3. **Clock Restarts:** The clock does not restart until the sponsor submits a complete response to the AI request that the FDA accepts for review. This "hold" period, during which the submission is with the sponsor, is a primary reason why total De Novo timelines can be unpredictable and often exceed the 150-day target. ### Common Reasons for De Novo Review Clock Pauses For novel devices characteristic of the De Novo pathway, AI requests are common. They often focus on areas where the agency needs greater assurance of the device's safety and effectiveness in the absence of a predicate. **What FDA Will Scrutinize:** * **Clinical and Non-Clinical Data:** The data must be sufficient to demonstrate a reasonable assurance of safety and effectiveness for the device's intended use. An AI request may ask for additional data, new statistical analyses, or clarification on study methodologies. * **Proposed Special Controls:** The De Novo submission must include a robust set of proposed Special Controls that can mitigate the identified risks. If these controls are deemed insufficient or unclear, the FDA will pause the review to request more detail. * **Device Description and Technology:** For a novel technology, the FDA may require further explanation of the device's mechanism of action, software algorithms (for SaMD), or material specifications. * **Cybersecurity and Software Validation:** For software-driven or connected devices, incomplete documentation regarding software verification, validation, and cybersecurity risk management is a frequent cause for an AI request. ### Strategic Considerations and the Role of Q-Submission The most effective strategy for navigating the De Novo process efficiently is to minimize the chances of a lengthy review clock pause. This requires a proactive approach centered on a high-quality submission and early engagement with the FDA. The Q-Submission (or Pre-Submission) program is an invaluable tool for De Novo sponsors. It provides a formal mechanism to obtain written feedback from the FDA *before* submitting the final De Novo request. Sponsors can use a Q-Submission to discuss and gain alignment on critical topics, including: * The proposed clinical study design. * The plan for non-clinical performance testing. * The adequacy of the proposed Special Controls. By addressing these key areas with the FDA in advance, sponsors can significantly increase the likelihood that their formal De Novo submission will be complete and clear, reducing the need for a major AI request and a long clock stoppage. Engaging the agency 3-6 months before a planned submission is often a valuable strategic step. ### Key FDA References For official information, sponsors should always refer directly to the FDA's website. Key documents related to this process include: * FDA's guidance on the De Novo Classification Process. * FDA's guidance on the Q-Submission Program. * General regulations for medical device controls, such as those found under 21 CFR. ### How tools like Cruxi can help Navigating the De Novo pathway requires meticulous organization of data, requirements, and regulatory correspondence. Tools like Cruxi can help teams structure their submission narrative, manage the extensive documentation required, and link evidence directly to the proposed Special Controls. This level of organization can help build a more comprehensive and review-friendly submission, potentially streamlining the 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.