Precise Infliximab Exposure and Pharmacodynamic Control

This study looks at the best way to dose infliximab (a biologic medication used to treat Crohn's disease) in children and young adults. Instead of using a fixed dose, researchers want to monitor drug levels in the blood and adjust doses individually to achieve better control of inflammation with fewer side effects. **You may be eligible if...** - You are 6–22 years old - You have been newly diagnosed with Crohn's disease within the last 90 days - You have never taken a biologic medication (like infliximab or adalimumab) before - You have active Crohn's disease confirmed by a colonoscopy or blood/stool tests - You have a negative tuberculosis (TB) test - If you are female and have started menstruating, you have a negative pregnancy test **You may NOT be eligible if...** - You have ulcerative colitis or indeterminate colitis (not Crohn's) - You have already received any biologic medication - You have had a recent abscess, internal fistula, or bowel complication requiring surgery - You have an active serious infection - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.