Subgroup Analysis of the Placebo-controlled CHARM Trial: Increased Remission Rates Through 3 Years for Adalimumab-treated Patients with Early Crohn's Disease

Background And Aims: We examined the impact of disease duration on clinical outcomes and safety in a post hoc analysis of a remission maintenance trial with adalimumab in patients with moderate to severe CD.

Methods: Patients in the CHARM trial were divided into 3 disease duration categories: <2 (n=93), 2 to <5 (n=148), and ≥5 years (n=536). Clinical remission and response rates at weeks 26 and 56 were compared between adalimumab and placebo subgroups, and assessed through 3 years of adalimumab treatment in the ADHERE follow-on trial. Logistic regression assessed the effect of disease duration and other factors on remission and safety.

Results: At week 56, clinical remission rates were significantly greater for adalimumab-treated versus placebo-treated patients in all 3 duration subgroups (19% versus 43% for <2 years; P=0.024; 13% versus 30% for 2 to <5 years; P=0.028; 8% versus 28% for ≥5 years, P<0.001). Logistic regression identified shorter duration as a significant predictor for higher remission rate in adalimumab-treated patients. Patients with disease duration <2 years maintained higher remission rates than patients with longer disease duration through 3 years of treatment. The incidence of serious adverse events in adalimumab-treated patients was lowest with disease duration <2 years.

Conclusions: Adalimumab was superior to placebo for maintaining clinical remission in patients with moderately to severely active CD after 1 year of treatment regardless of disease duration. Clinical remission rates through 3 years of treatment were highest in the shortest disease duration subgroup in adalimumab-treated patients, with a trend to fewer side effects.