Pharmacodynamic and Clinical Outcome Study of Mongersen in Patients With Crohn's Disease

During Induction period patient will receive mongersen 160 mg daily for 12 weeks. This study also offers subjects the option to continue with maintenance treatment at the discretion of the Investigator, beginning after the Week 12 Visit with alternating no IP for 4 weeks, followed by mongersen (GED-0301) 160 mg QD for 4 weeks, up through the Week 52 Visit during the Maintenance Period. At Week 52, subjects who have achieved an endoscopic improvement of \>50% from baseline based on the SES-CD, as assessed by the central reader, and clinical improvement (HBI \<7), will have the option to continue receiving treatment for an additional year, up through Year 2 (ie, the Week 100 Visit).