A Study to Investigate Efficacy and Safety of SAR441566 in Patients With Crohn's Disease.

This is a phase 2, multinational, multicenter, randomized, double-blind, placebo-controlled, dose ranging study to evaluate the efficacy and safety of SAR441566 in adults with moderate to severe Crohn's Disease (CD). The primary objective of this study is to assess the efficacy of different doses of SAR441566 compared with placebo in participants with moderate to severe CD.

This study will have an anticipated duration of up to 59 weeks which will include a screening period of 4 weeks (+7 calendar days if needed), followed by the Main Study (MS) treatment period, lasting 52 weeks, and a 2-week follow-up period after end of treatment for participants not enrolling in the Long Term Safety (LTS) study. The MS period includes a Double-Blind (DB) treatment period with 12 weeks of induction followed by 40 weeks of maintenance.

Additionally, an Open Label (OL) period of up to 40 weeks will be offered to eligible participants. The combined duration of the DB maintenance and OL periods cannot exceed 40 weeks, depending on when participants switch.