An FDA reviewer has a list of questions regarding a submitted 510(k) application. What is the best course of action for the regulatory professional?

In the context of responding to an FDA reviewer's questions on a 510(k) application, sending a letter with an anticipated response time is the best practice. This approach demonstrates professionalism and transparency.

When faced with questions from the FDA, it is important to acknowledge their request and provide an estimated timeframe for a comprehensive response. This not only keeps the lines of communication open but also sets the FDA's expectations regarding when they can expect to receive further information or clarifications.

Sending such a letter can be pivotal in maintaining a good relationship with the regulatory body and can help to facilitate a more efficient review process. It also shows that the regulatory professional is proactive and organized in addressing the FDA's concerns, which can help to build trust and confidence in the application process.

While other options may seem like valid approaches, they do not provide an immediate acknowledgment of the reviewer’s questions or set an explicit timeline for follow-up. For instance, meeting requests may consume additional time and may not lead to a timely resolution, while simply responding within 90 days without indicating an expected timeframe may leave the reviewer without guidance on when they might receive the needed information.