This study is testing a new medicine called SAR442970 to see if it helps people with Crohn's disease, a condition where parts of the digestive system become swollen. The study is randomized (participants are randomly assigned to groups), double-blind (neither participants nor doctors know who gets the real medicine), and has three arms (different treatment groups). It compares SAR442970 to a placebo (a substance with no active drug) to check its effectiveness and safety.

Here are some key things to know:

• The study lasts up to 168 weeks, and treatment can continue for up to 158 weeks, including an extension for some.
• Participants must have moderate to severe Crohn's and tried other treatments without success.
• People with certain other conditions or those who have had recent bowel surgery cannot join.