Drug efficacy studies typically proceed through several phases:
1. Phase I: Tests the safety of the drug in a small group of healthy volunteers. 2. Phase II: Explores the drug's efficacy and side effects in a larger group of patients. 3. Phase III: Confirms the drug's effectiveness in a large cohort and compares it against standard treatments. 4. Phase IV: Post-marketing studies that monitor the drug's performance in the general population.
