GED-0301 is an antisense oligodeoxynucleotide with a sequence complementary to the Smad7 mRNA transcript. Smad7 is a negative regulator of transforming growth factor-β, which is increased in the intestinal mucosa of patients with active Crohn’s disease (CD). We randomly assigned 63 CD patients to 4-, 8-, or 12-week treatment groups receiving oral GED-0301 (160 mg/day). The primary objective was to determine GED-0301’s effect on endoscopic CD measures; secondary objectives included effects on clinical activity.