臨床試驗各階段的定義

TFDA (台灣衛福部):

  第一階段:
    目的: 人體藥理試驗
  
  第二階段:
    目的: 療效探索; 決定第三階段的使用劑量及治療方法
  
  第三階段:
    目的: 確認安全及有效

  第四階段 (上市後試驗):
    目的: 治療用途之試驗

FDA:

  Phase 1:
    Purpose: Safety and dosage
    Participants: 20 to 100 people
    Length: several months
    
  Phase 2:
    Purpose: Efficacy and side effects
    Participants: Up to several hundred people
    Length: Several months to 2 years
    
  Phase 3:
    Purpose: Efficacy and monitoring of adverse reactions
    Participants: 300 to 3,000 people
    Length: 1 to 4 years
    
  Phase 4 (post market surveillance):
    Purpose: Safety and efficacy
    Participants: Several thousand
 
 ### Reference
 
  FDA: Clinical Research
 
 Wikipedia: Phases of clinical research
 
 台灣醫藥臨床試驗資訊網