Obtaining approval to market a new drug frequently takes between 6 months and 2 years. Late-stage drug development studies of approved, marketed drugs may continue from several months to several years. Phase IIIb trials, which often begin before approval, may supplement or complete earlier trials by providing additional safety data or they may test the approved drug for additional conditions for which it may prove useful. Post-Marketing Studies . Post-marketing studies test a marketed drug in new age groups or patient types.
Some studies focus on previously unknown side effects or related risk factors.
As with all stages of drug development testing, the purpose is to ensure the safety and effectiveness of marketed drugs. Inc. All rights reserved.