This study is being done to examine the long-term safety and efficacy of an investigational drug (CP-690,550) in children with Juvenile Idiopathic Arthritis (JIA). This is an extension of a previous treatment study and subjects can only participate if they were in the previous study.
Subjects will be in this study for up to 10 years. The total duration of an individual subject’s participation may vary depending upon when they entered the trial.
Subjects will receive the medication in either liquid or tablet form, depending on his/her age and weight.
- If a subject is less than 12 years old or under 40kg (88 lbs.), the study medicine will be a liquid that he/she can drink;
- If a subject is older than 12 years old or greater than 40kg (88lbs.), the study medicine will be a tablet. If the subject is unable to swallow a pill, they will be able to take the medicine as a liquid.