Post-marketing studies, carried out after licensure of the drug. Generally, a Phase IV trial is a randomized, controlled trial that is designed to evaluate the long-term safety and efficacy of a drug for a given indication. Phase IV trials are important in evaluating AIDS drugs because many drugs for HIV infection have been given accelerated approval with small amounts of clinical data about the drugs effectiveness.
Phase IV trials are conducted after a treatment is on the market and help to provide additional information about the treatment's risks, benefits, and best use.
Post-marketing studies to delineate additional information including the drug's risks, benefits, and optimal use.