Phase 2 Clinical Trials

During phase 2 clinical trials the drug in question is given to people who have the disease or condition that it is intended to treat. The main purpose is to see if the drug has any effect on the disease and in addition, to test the safety of the drug. Based on the results of the phase 1 clinical trials a certain dose or doses of the drug will be studied; additionally, the drug may also be compared to other already approved drugs that are being used to treat the dose in order to see if it is as safe as or at least as good as these. The drug may also be compared to a placebo during this phase. In this case the study is usually randomized and "blinded" with one group receiving the treatment and another "control" group receiving a placebo. A "blinded" study means that none of the participants (and in some cases even the researchers) do not know which one the individual participants are receiving.

The other thing that researchers start to focus on during this phase of clinical trials are side effects, this is where they begin to gather the side effect profile of the drug being studied. Other key areas of research during this phase include:

• Drug bioavailability: this means basically how available the drug is within the body once it is ingested
• Interactions: both drug-drug and drug-disease i.e. interactions of the drug with other drugs and with other diseases
• Pharmacodynamics: i.e. studying what the drug does to the body
• Pharmacokinetics: i.e. studying what the body does to a drug (how the body absorbs it, breaks it down, distributes it and then gets rid of it)

Phase 2 Clinical Trials Snapshot

• Goal: Does it work?
• Number of Participants: ~100 to 300 (sometimes up to 500)
• Duration: months to years (usually a maximum of 2 years)
• Outlook: about 33% of drugs advance successfully from phase II clinical trials to phase III clinical trials

A doctor is a healthy person who can't
keep away from sick people.

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May 25, 2009

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