A Study of Vedolizumab in Children and Teenagers With Moderate to Severe Crohn's Disease (CD)

To join this study, children and teenagers generally need to be aged between 2 and 17 years old and weigh at least 10 kg (about 1 stone 8 pounds). They must have Crohn's disease that is moderately to severely active, which means their symptoms are significantly affecting them. Importantly, they should have already tried and not responded well to, or couldn't tolerate, at least one other standard treatment for Crohn's disease, such as certain medicines or special diets.

There are also some reasons why someone might not be able to join. For example, if they have certain serious brain or spinal cord conditions, or if they have recently received other experimental study medicines. All participants must have had their Crohn's disease diagnosed at least one month before starting the study.

If you join this study, here’s what you can expect:

**Medicine:** You will receive the study medicine, vedolizumab, through a drip into a vein (IV infusion).

**Initial Treatment:** For the first six weeks, you will have three infusions: one at the very beginning, one after two weeks, and another after six weeks. The amount of medicine you get will depend on your weight.

**Continuing Treatment:** After these initial doses, if your condition has improved, you will then be randomly assigned (like flipping a coin) to receive either a high or a low dose of vedolizumab. You’ll get an infusion of this dose once every eight weeks until Week 46 of the study. Neither you nor your study doctor will know if it’s the high or low dose, unless there's a medical reason to find out.

**Assessments:** Throughout the study, you’ll have regular check-ups with the study team. These visits will likely include blood tests, physical examinations, and possibly endoscopies (where a small camera looks into your gut) to see how your Crohn's disease is responding. The total duration of active treatment in the study will be about 46 weeks.