IND Application: Required Before Testing a New Drug in People

Once a drug is ready to move from the lab to the clinic, its legal status changes—it now falls under the requirements of the drug regulatory system. In the US, this transition is facilitated by an IND. Reviewed and cleared by the FDA, the IND authorizes the start of clinical studies, whether with a new drug or with an approved drug being tested for a new use.

Although the IND is the standard in the US, other countries and regions have their own similar regulatory documents, such as the Clinical Trial Application (CTA) used by the European Medicines Agency (EMA).

The IND does far more than summarize how a drug works or might work in humans. It includes a wide range of information: data from in vitro and animal studies demonstrating safety in validated models, details on dosing and potential side effects, and plans for how the drug will be tested in people—including trial design and patient protections.

Specifically, an IND application must address three key areas: animal pharmacology and toxicology studies, manufacturing information, and clinical protocols with investigator details. While the researcher and her team had gathered compelling proof-of-concept data, they were still early in development and lacked definitive safety studies. To help chart the path forward, they met with experts in chemistry, manufacturing, and controls (CMC), toxicology, and clinical trial design to better understand the types of studies and planning required for their IND application.

With a more advanced development program in hand, the researcher sought feedback from FDA to anticipate potential concerns and ensure their plan was on track. For this, she scheduled a pre-IND meeting—typically the first formal interaction between a sponsor and the agency. While optional, these meetings are highly encouraged to facilitate IND preparation and the review process.

Taking the FDA’s advice into account, the research team reviewed the data demonstrating their drug’s safety for initial human testing, compiled detailed manufacturing information, and finalized protocols to monitor safety during early clinical trials. Confident they were ready, they submitted their application to the FDA. Then began the waiting game: 30 days in which the agency could either place a clinical hold on the application pending additional data or grant clearance to proceed. When the green light finally came, the team was ready to launch their first clinical trial—a hard-earned milestone worth celebrating.

The IND journey doesn’t end with FDA authorization. Once an IND is cleared, the sponsor must maintain it by submitting periodic updates, allowing the FDA to monitor ongoing safety and stay informed about changes to protocols or personnel. In this way, the IND becomes a living document—evolving alongside the development program.