Clinical Pharmacology Studies

Under construction

The concept of “Phases” in clinical drug development originates from the FDA, after WW2. Most clinical pharmacology studies are Phase 1 studies, when we learn about the PK of the drug. In Phase 2, we learn about the PD of the drug. In Phase 3, we confirm our efficacy and safety hypotheses in the target population.

Figure 1: Clinical pharmacology in drug development and evaluation.
Figure 2: Timing of human pharmacology studies.

Phase 1: First in Human

  • First in human (FIH) PK/PD
    • Single ascending dose (SAD)
    • Multiple ascending dose (MAD)
  • Food effect (for oral drugs)
  • Pharmacogenomics (CYP genotyping)

Phase 2

  • Mass Balance/ADME
  • Drug-drug interaction (DDI) in vivo
  • QT study
  • Dose identification
  • Healthy vs Patient PK & PD
  • Relevant special populations
    • Renal impairment (RI)
    • Hepatic impairment (HI)
    • Pediatrics
    • Elderly
    • Pregnant
    • Lactating
    • Obese
    • other

Phase 3

  • Bioequivalence (BE), eg between formulations or drug combinations
  • Exposure-efficacy/safety in target population