What to Expect During the NDA Review Process

February 21, 2012

Compiling and submitting an NDA is a complicated and intensive activity. Once you have submitted your application to FDA, you may be curious about what can you expect to hear and when. Below are some of the common questions we receive from sponsors about what to expect during the NDA review process.

When will I know that my NDA has been accepted for filing?

You will know within 60 days of submitting your NDA whether it has been accepted for filing (or conversely, if FDA refuses to file your application due to lack of information or studies). If your application is accepted for filing (60 days after submission), then you will receive an FDA 74-day letter, which contains a planned NDA review timeline that varies based on several factors such as whether other similar drugs already exist or whether your drug treats an unmet medical need.

The FDA 74-Day letter also confirms your action date, confirms standard versus priority review, and identifies any preliminary deficiencies in your application. Sponsors must act quickly to resolve the deficiencies noted in the FDA 74-day letter during the NDA review process, so it’s advisable to seek outside assistance from an experienced compliance consultant.

How many information requests can we expect to receive during the NDA review process?

The answer is that it varies, and there really is no predicting how eventful your review will be. Throughout the course of the Agency’s review, there are likely to be issues that come up, but the number and significance of these requests will vary from application to application. Hopefully you took the time to ensure that all of the components of your NDA were accurate and complete, and you reviewed any previous correspondence with the Agency to make sure that all issues were addressed. However, FDA may request clarification on where information resides in your NDA, clarification on information you already provided, or they may request additional analyses. You should also be prepared for an inspection of the facility or facilities where the drug will be manufactured, which may result in additional requests.

Regardless of how many information requests you receive during the NDA review process, it is important that you make sure you understand what FDA is asking for and that you respond with information that is clear, comprehensive and transparent. This will help the reviewers understand your response and minimize the need for additional follow-up questions or requests. It is the sponsor’s responsibility to respond to these requests as soon as possible, as timely and complete responses help ensure that you don’t inadvertently push out your action date.

When does label negotiation occur during the NDA review process?

This very critical step takes place at the very end of the review, in many cases in the last two weeks. Tensions often run high during this period, since many parties have an interest in the final wording of the label. You should have developed strong, data-driven statements about your product prior to submission, but you need to be prepared to defend those statements now. Because timing and responsiveness is critical at this stage, all important members of your team should be available to review versions of labels and participate in calls on very short notice.

NDA submission and review timeline

The NDA review process is long and complex, so make sure you’re aware of what to expect during each step so you have plenty of time to prepare in advance. The FDA has provided the following NDA timeline to help visualize the entire process.

NDA Submission Review Timeline Chart
NDA Submission Review Timeline Timeline. (Source: FDA)

Whether you are compiling an NDA for submission or responding to requests during FDA review, it is important to remember that an NDA is the most important and most complex series of documents that you will need to assemble during your product’s lifecycle. An accurate and complete NDA is critical to ensuring a streamlined review and maximizing the likelihood of product approval.

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