Sponsor decision not to start trial

The purpose of study is to test the effect of an experimental medication GED-0301(mongersen) and evaluate its safety in patients (≥ 12 years of age) with active Crohn's disease. The study will test GED-0301 compare to placebo for 12 weeks. The study treatment is blinded which means that patients and the study doctor will not know which treatment has been assigned. Patients in this study will be allowed treatment with stable doses of oral aminosalicylates, oral corticosteroids, immunosupressants and antibiotics for the treatment of Crohn's disease. Adolescent patients will also be allowed treatment with stable doses of exclusive enteral nutrition and growth hormone.

All patients who complete the study will have the option to enter a long term active treatment study.

Inclusion Criteria:

Subjects must satisfy the following criteria to be enrolled in the study:

• Male or female ≥ 12 years
• Subject is able to swallow the IP tablets
• Active Crohn's disease (CD) disease as determined by the Crohn's Disease Activity Index (CDAI) score and the Simple Endoscopic Score for Crohn's Disease (SES-CD)
• Must meet a determined average minimum number of daily stools or rating of abdominal pain over a 7day period
• Subject must have failed or experienced intolerance to at least one of the following: budesonide; systemic corticosteroids; immunosuppressants (eg, azathiopurine, 6-mercaptopurine, or methotrexate); or biologics for the treatment of CD (ie, infliximab, adalimumab, certolizumab, or vedolizumab).

Exclusion Criteria:

• The presence of any of the following will exclude a subject from enrollment: Diagnosis of ulcerative colitis (UC), indeterminate colitis, ischemic colitis, microscopic colitis, radiation colitis or diverticular disease-associated colitis, or colitis due to immunodeficiency

• Local manifestations of Crohn's Disease (CD) such as abscesses, short bowel syndrome; or other disease complications for which surgery might be indicated or could confound the evaluation of efficacy
• Subject has strictures with prestenotic dilatation, requiring procedural intervention, or with obstructive symptoms. In addition, subjects with colonic strictures that are not passable with an age-appropriate colonoscope, or strictures in the ileum or ileocecal valve that are fibrotic in nature, will be excluded
• Intestinal resection within 6 months or any intra-abdominal surgery within 3 months prior to the Screening Visit
• Ileostomy or a colostomy
• Subject has a history of any clinically significant medical condition that, in the investigator's opinion, would prevent the subject from participating in the study
• Adolescents with delayed growth or pubertal development who are on corticosteroids at baseline and who should not continue treatment with the same dose of corticosteroids until the Week 12 visit.