FDA Complete Response Letter

A FDA Complete Response Letter (CRL) is a communication from the U.S. Food and Drug Administration (FDA) that indicates the agency’s review of a New Drug Application (NDA) or Biologics License Application (BLA) has been completed, but the application cannot be approved in its current form. The letter outlines specific deficiencies that must be addressed before the FDA can consider the application for approval.

For example, if a pharmaceutical company submits an application for a new medication but the FDA finds issues related to the clinical trial data, manufacturing processes, or labeling, the FDA will issue a CRL detailing these concerns. The company must then respond to the points raised in the CRL before resubmitting the application.

In a notable case, in 2020, the FDA issued a CRL to a drug company for a proposed treatment for a rare disease due to insufficient evidence of efficacy and concerns regarding safety data. The company subsequently conducted additional studies and submitted a revised application, which the FDA later approved.