Clinical Trials

Phase I - "Is it Safe?"

• Purpose: Safety, toxicity, pharmacokinetics, pharmacodynamics
• Participants: Small number of healthy volunteers (or patients with the disease if drug is toxic, e.g., chemo)
  • 20-80 (1 zero)
• Key Point: First-in-human → assess safe dosage range and side effects

Phase II - "Does it Work?"

• Purpose: Efficacy and side effects
• Participants: Larger group of patients with the disease
  • 100-300 (2 zeros)
• Key Point: Looks for therapeutic effect and continues safety monitoring

Phase III - "Is it Better?"

• Purpose: Compare new treatment to standard of care or placebo
• Participants: Large groups of patients (randomized, controlled)
  • 1,000-3,000 (3 zeros)
• Key Point: Randomized controlled trials (RCTs) to establish if the new treatment is better, same, or worse than existing therapies
• Result: Can lead to FDA approval

Market release

Phase IV - "Can we keep it?"

• Purpose: Post-marketing surveillance
• Participants: General population (real-world data)
• Key Point: Detects rare or long-term adverse effects, ongoing safety evaluation
• Result: Can lead to drug withdrawal or labeling changes

"SWCMF" for Phases I–IV

• S = Safety (I)
• W = Works (II)
• C = Compare (III)
• M = Market release
• F = Follow up (IV)
  • Taken to market (FDA approval between III & IV)