Drug developers, or sponsors, must submit an Investigational New Drug (IND) application to FDA before beginning clinical research.
In the IND application, developers must include:
Animal study data and toxicity (side effects that cause great harm) data
Manufacturing information
Clinical protocols (study plans) for studies to be conducted
Data from any prior human research
Information about the investigator
The FDA review team has 30 days to review the original IND submission. The process protects volunteers who participate in clinical trials from unreasonable and significant risk in clinical trials. FDA responds to IND applications in one of two ways:
Approval to begin clinical trials.
Clinical hold to delay or stop the investigation.
A clinical hold is rare; instead, FDA often provides comments intended to improve the quality of a clinical trial. In most cases, if FDA is satisfied that the trial meets Federal standards, the applicant is allowed to proceed with the proposed study.
The developer is responsible for informing the review team about new protocols, as well as serious side effects seen during the trial. This information ensures that the team can monitor the trials carefully for signs of any problems. After the trial ends, researchers must submit study reports.
This process continues until the developer decides to end clinical trials or files a marketing application. Before filing a marketing application, a developer must have adequate data from two large, controlled clinical trials.
source: fda.gov