What is a Clinical Research Organization?

Phase I

• Establishes the effect of a new drug in humans
• Usually conducted on small (12-50) populations of healthy volunteers and/or patients
• Determines a drug's toxicity, absorption, distribution, metabolism and excretion

Phase II

• Tests a drug for safety and efficacy in a relatively small (200-500) population of patients
• Patients are afflicted with the disease or condition for which the drug is being developed

Phase III

• Tests the drug in relatively large populations of patients (500-5,000 or more)
• Usually compares the new drug to placebo or to the standard therapy currently being used for the disease of interest
• Results usually provide package insert info (Prescribing Information for doctors, and Patient Information materials)

Phase IV

• Conducted after a drug has been approved by a Regulatory Authority
• Compares the drug to competitor drugs, to explore additional patient populations or disease indications, or to further assess the safety of the drug