What are the stages of drug development?

The typical stages are: (1) laboratory research; (2) preclinical studies in animal models to test safety and biological activity; (3) Phase 1 trials in a small number of people to assess safety of the new therapy; (4) Phase 2 trials looking for signs that the new therapy is effective; (5) Phase 3 trials in a larger population to confirm effectiveness; and (6) regulatory review and approval of the treatment. Not all therapies make it through every stage.

Developing a new therapy is a long, expensive and challenging process that can take many years, and not every drug makes it through every stage. Many promising treatments do not complete the developmental journey but each study, even when a therapy is not successful, adds valuable knowledge that helps guide future research.