Definitions for "Open Label"
No individuals are blinded to treatment assignment (eg, investigators, subject and sponsor know the identity of the treatment assignment).  For randomized open label trials, the "blind" with respect to the randomization sequence should be maintained up to the time when a patient is actually randomized.
An open label study occurs when everyone involved in the study, including parents, children, and the investigators, know which study treatment the child is receiving.
A type of clinical trial in which researchers and participants know who is taking the experimental drug.