A Long-term Active Treatment Study of Mongersen (GED-0301) in Subjects With Crohn's Disease

The purpose of this study is to assess long-term safety data of GED-0301 for a period of up to 208 weeks in adult subjects (i.e., ≥ 18 years of age) who participated in the core Phase 3 GED-0301-CD-002 and GED-0301-CD-003 studies and adolescent subjects (i.e., 12 to 17 years of age) who participated in the core Phase 3 GED-0301-CD-003 study. Although all subjects will receive active treatment, this study is double-blinded for the entire 208 weeks for the purpose of preserving the blind of the subject's treatment allocation in the initial, core Phase 3 GED-0301 study.

The GED-0301-CD-003 trial was not initiated; see detailed description.

This is a long-term active treatment study in patients with Crohn's disease (CD). Subjects who met the early escape criteria in Study GED-0301-CD-002, or subjects who completed Study GED-0301-002 or GED-0301-003, may be eligible for this study. Primary objective is to assess long-term safety of GED 0301. Additional efficacy and patient reported outcomes will be explored.

There are 5 possible treatment groups for GED-0301-CD-002 Subjects (Groups 1-5). There are 3 possible treatment groups for GED-0301-CD-003 subjects (Groups 1-3). Treatment is assigned based on clinical improvement achieved or not achieved from the core GED-0301 study.

1. continuous GED-0301 160 mg once daily for 12 weeks, followed by alternating placebo once daily for 4 weeks with GED-0301 160 mg once daily for 4 weeks, through Week 208;
2. alternating GED-0301 160 mg once daily for 4 weeks with placebo once daily for 4 weeks, through Week 208;
3. alternating placebo once daily for 4 weeks with GED-0301 160 mg once daily for 4 weeks, through Week 208;
4. continuous GED-0301 40 mg once daily through Week 208;
5. alternating placebo once daily for 4 weeks, followed by GED-0301 40 mg once daily for 4 weeks, through Week 208.

The GED-0301-CD-003 trial was not initiated; the GED-0301 program was terminated; no safety findings were noted.

Eligibility Criteria:
Inclusion Criteria for Adult Subjects:

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

* Male or female ≥ 18 years of age.
* Subject must have participated in the GED-0301-CD-002 or GED 0301 CD 003 study.
* Subject must use protocol approved contraception.

Inclusion Criteria for Adolescent Subjects:

Adolescent subjects must satisfy the following criteria to be screened and enrolled in the study

* Male or female 12 to 17 years of age.
* Subject must have participated in the GED 0301 CD 003 study.
* Subject is able to swallow the IP tablets.
* Subject must use protocol approved contraception.

Exclusion Criteria for Adult and Adolescent Subjects:

The presence of any of the following will exclude a subject from screening and enrollment:

* Subject had experienced a serious adverse event (SAE) related to the investigational product while participating in the previous Phase 3 GED-0301 study.
* Subject has initiated biologic agents, such as TNF-α blockers or integrin antagonists.
* Subject is pregnant or breastfeeding.
* Subject has developed a known hypersensitivity to oligonucleotides, GED 0301 or any ingredient in the investigational product.