Issued by the U.S. FDA when communicating a decision to a drug company that an NDA or ANDA to market a new or generic drug will not be approved in its present form. Before August 2008, the FDA used Approvable and Not Approvable letters in these cases, but moved to CRLs to “provide a more consistent and neutral mechanism to convey that our initial review of an application is complete and we cannot approve the application in its present form,” according to an FDA statement. For BLAs, the FDA has used CRLs since 1998.