This excerpt taken from the ELN 20-F filed Mar 30, 2006.
ENACT-2 Phase 3 Crohns Disease Maintenance Trial
ENACT-2 was a Phase 3, double-blind, placebo-controlled, international maintenance trial of Tysabri in CD enrolled responders from ENACT-1 (a three-month double-blind, placebo-controlled study in patients with moderately to severely active CD). Tysabri responders from ENACT-1 (339 patients) were re-randomized after the three-month study to one of two double-blind treatment groups: Tysabri (300 mg IV) or placebo, both administered monthly for a total of 12 months. The primary endpoint of ENACT-2 was sustained maintenance of response throughout the first six months of treatment.
We presented six-month data from the ENACT-2 study at the DDW in May 2004. Twelve-month ENACT-2 data was presented as part of a regulatory filing announced and subsequently presented at the 12th Annual United European Gastroenterology Week meeting in September 2004.
The data presented at the DDW showed Tysabri maintained clinical response and remission rates throughout six months among patients with Crohns disease who had previously achieved clinical response. At six months, 61 percent of Tysabri-treated patients exhibited significant clinical response versus 28 percent of patients re-randomized to receive placebo, and clinical remission was maintained by 44 percent of patients receiving Tysabri versus 26 percent of placebo-treated patients. Forty-nine percent of Tysabri-treated patients who were also on chronic corticosteroid therapy were able to withdraw from corticosteroids and maintain response, in contrast to 20 percent of patients on placebo. There were no notable differences in the rate of serious or non-serious adverse events between treatment groups. The most frequently reported adverse events were headache, nasopharyngitis, nausea and abdominal pain.