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Groins

Phase II clinical trial determines the effectiveness and safety of the candidate drug in patients suffering from the condition the new drug is designed to treat.

The main question that is answered in phase II studies is: "What is the most effective dosage range and the drug safety within that range?"

Phase II studies enroll 100 to 300 subjects, and depending upon the type of investigational drug and the condition it treats, the trial lasts anywhere from six months to two years.

Phase 2 is sometimes further classified into 2a and 2b phases based on the type of trials:

Phase 2a assesses the amount of drug to be given to the subject for optimal results.
Phase 2b assesses the how well the drug works at the prescribed dosage levels