open label extension study definition
As the name implies, an open-label extension study is an âappendageâ to a randomised controlled clinical trial, usually of an unregistered medicine or intervention. Often the drug is being studied under an investigational new drug (IND) licence or equivalent legislation.he number of open-label extension studies being performed has increased enormously in recent years. Often it is difficult to differentiate between these extension studies and the double-blind, controlled studies that preceded them.