|
Phase |
Purpose |
Time |
|
Preclinical |
Assessing the safety and biological activity using animal models in the laboratory No participants |
3- 6 years |
|
Phase 1 |
Determining which dose is safe, how often if should be given and the best form of treatment Few participants |
1-2 years |
|
Phase 2 |
Assessing the effectiveness of the treatment, its side effects and tolerance levels More participants |
2-4 years |
|
Phase 3 |
Determine whether the new treatment works better than an alternative current standard treatment Most participants - often 100+ |
3-5 |
|
Phase 4 |
Phase 4 studies are done once the drug or treatment is available on the market. They usually involve new participants are done to gather long term safety information on the new treatment. |
2-5 years |