When is an investigational new drug application filed with the FDA?

An investigational new drug application (IND) is a critical step in the drug development process that is filed with the FDA prior to human testing of any new drug entity. This submission is essential as it allows the sponsor to legally conduct clinical trials with human subjects. The IND includes data from preclinical studies, information about the drug's composition and manufacturing, and a proposed clinical trial protocol.

Filing the IND before human trials ensures that the FDA has the opportunity to review the safety data and the design of the proposed studies to protect the participants and facilitate well-controlled testing for efficacy and safety. It serves as a safeguard for public health, as it mandates a review of the investigational drug's safety data collected during laboratory and animal studies before human exposure begins.

Other phases of drug development, such as animal testing or trials conducted after Phase III, do not warrant the submission of an IND because they either occur before human testing is planned or relate to the final stages of approval processes. Thus, understanding the timing of the IND submission is essential for regulatory compliance and ensuring the safety of clinical trial participants.