Clinical research involves testing an investigational drug or device in humans. Each clinical trial must use a protocol that has been written according to government regulations and that is also approved by the company sponsoring the study. An investigational drug may be: a drug that has not yet been approved for marketing (i.e., a drug that is not allowed to be sold) a drug that is currently on the market but that is being studied for a non-approved indication or is being studied in a new route of administration, strength, or formulation; a drug that is being sold on the market by one company but that is being considered for in-license or acquisition by another company; a drug that contains known and established ingredients but has not yet been marketed by the company; a drug that is currently on the market but is being studied in a population for which the  drug has not yet been approved, such as in children or in elderly patients.
 

Before an investigational drug or device can be studied in humans, its safety and effectiveness is carefully studied in the laboratory. However, this early research cannot predict how safe and effective the drug will be in humans. With any new treatment there may be benefits as well as known and unknown risks. Clinical research trials are conducted to determine whether promising new treatments will be safe and effective for patients.