If the results of phase 2 trials are promising and prove the efficacy of the new treatment modality, the drug then goes on to phase 3 trials. A phase 3 trial makes a comparison of the new treatment with the existing standard treatments to see if the new treatment is better. This treatment is then given to large group of people. It involves thousands of patients in many different hospitals and even different countries. The larger the number of people participating in the trial, the more confident a researcher can be of the results. |