There are four phases of Clinical Trials.

Phase 1

• First studies that involve humans
• Test how the drug should be given and if it is safe
• Small numbers of healthy volunteers or terminally ill people

• Duration – days to weeks

Phase 2

• Look at safety and efficacy
• Seek to find the best dose – maximum benefit and minimum side effects
• More people involved, usually 50 – 200

• Duration – months to years

Phase 3

• Confirm safety and efficacy
• Often comparison with 'standard of care' drug
• Larger numbers of people, 100 – 1000’s
• Duration – months to years

• Provide the data for government approval of drugs

Phase 4

• Long term safety monitoring and information gathering
• Post marketing approval

At San Clinical Trials Unit we concentrate on Phase 2, 3 and 4 clinical trials.