Mongersen (GED-0301) for Active Crohn's Disease: Results of a Phase 3 Study

The objective was to assess the efficacy and safety of GED-0301, an antisense oligodeoxynucleotide to Smad7, in active Crohn's disease (CD).

This phase 3, blinded study randomized patients (1:1:1:1) to placebo or 1 of 3 once-daily oral GED-0301 regimens: 160 mg for 12 weeks followed by 40 mg continuously or alternating placebo with 40 or 160 mg every 4 weeks through week 52.

In all, 701 patients were randomized and received study medication before premature study termination; 78.6% (551/701) completed week 12, and 5.8% (41/701) completed week 52. The primary endpoint, clinical remission achievement (CD Activity Index score <150) at week 12, was attained in 22.8% of patients on GED-0301 vs 25% on placebo (P = 0.6210). At study termination, proportions of patients achieving clinical remission at week 52 were similar among individual GED-0301 groups and placebo. More placebo vs GED-0301 patients achieved endoscopic response (>50% decrease from baseline Simple Score for CD) at week 12 (18.1% vs 10.1%). Additional endoscopic endpoints were similar between groups at weeks 12 and 52. More placebo vs GED-0301 patients had clinical response (≥100-point decrease in the CD Activity Index score) at week 12 (44.4% vs 33.3%); at week 52, clinical response rates were similar. Adverse events were predominantly gastrointestinal and related to active CD, consistent with lack of clinical and endoscopic response to treatment. Two deaths occurred (GED-0301 total group) due to small intestinal obstruction and pneumonia; neither was suspected by the investigator to be treatment-related.

GED-0301 did not demonstrate efficacy vs placebo in active CD.