P&S Journal: Fall 1995, Vol.15, No.3
Clinical Trials: Recruitment, Sometimes Easy Sometimes a Thankless Task. The Adventures of Six Clinicians Recruiting Patients for Trials By Lynne Christensen;
The Clinical Trials Process

Drug Approval
Before new drugs are approved by the Food and Drug Administration and made widely available, they must pass through a rigorous series of trials. Once a compound is identified in the laboratory as having potential therapeutic value, it is subjected to preclinical trials, which involve extensive laboratory and animal testing. The goal of these studies is to determine whether the compound is biologically active and safe.

If the compound proves effective in preclinical trials, human clinical testing can begin. Clinical trials are conducted in three phases.

• Phase I: These tests generally involve a small number of healthy volunteers to determine the drug's pharmacological actions; its safe dosage range; how it is absorbed, distributed, metabolized, and excreted; and the duration of its therapeutic action.

• Phase II: These are controlled studies in a small number of patients (up to 300) who suffer from the condition the drug is intended to treat. The studies

  are designed to test the drug's effectiveness. Simultaneous animal and human studies are also conducted to continue assessing the drug's safety.

• Phase III: These are large-scale studies (1,000 to 3,000 patients) designed to confirm earlier efficacy studies and to identify the frequency of adverse reactions. Once clinical trials are completed, a New Drug Application is filed with the FDA, which determines whether to approve the drug for widespread marketing.