Treatment of active Crohn's disease with MLN0002, a humanized antibody to the alpha4beta7 integrin.

BACKGROUND & AIMS: Selective blockade of lymphocyte-vascular endothelium interactions in the gastrointestinal tract is a promising therapeutic strategy for inflammatory bowel disease. This randomized, double-blind, controlled trial assessed the efficacy and safety of MLN0002, a monoclonal antibody targeting the alpha4beta7 integrin, in patients with active Crohn's disease. METHODS: Patients were randomized to receive MLN0002 2.0 mg/kg (n = 65), MLN0002 0.5 mg/kg (n = 62), or placebo (n = 58) by intravenous infusion on days 1 and 29. The primary efficacy end point was clinical response (>or=70-point decrement in the Crohn's Disease Activity Index [CDAI] score) on day 57. Secondary end points were the proportions of patients with clinical remission (CDAI score or=100-point decrement in CDAI). Human anti-human antibody levels were measured. RESULTS: Clinical response rates at day 57 were 53%, 49%, and 41% in the MLN0002 2.0 mg/kg, MLN0002 0.5 mg/kg, and placebo groups. Clinical remission rates at day 57 were 37%, 30%, and 21%, respectively (P = .04 for the 2.0 mg/kg vs placebo comparison). At day 57, 12% and 34% of patients in the 2.0- and 0.5-mg/kg groups had clinically significant human anti-human antibody levels (titers > 1:125). There was one infusion-related hypersensitivity reaction. The most common serious adverse event was worsening of Crohn's disease. CONCLUSIONS: This phase 2 study was suggestive of a dose-dependent beneficial effect of MLN0002 therapy on clinical remission. MLN0002 was well tolerated in patients with active Crohn's disease.