Exploring the use of adalimumab for patients with moderate Crohn's disease: subanalyses from induction and maintenance trials.

BACKGROUND Anti-TNF agents are often reserved for patients with severe Crohn's disease (CD). AIMS We explored the predictive value of baseline disease activity and C-reactive protein (CRP) for disease course, adalimumab efficacy for remission (induction and maintenance) in patients with moderate and severe CD, and adalimumab efficacy in moderate CD by CRP category. METHODS Post hoc analyses of remission data were performed for all randomized patients from induction (CLASSIC I) and maintenance (CHARM, EXTEND) adalimumab trials in patients with moderate (CDAI≤300) or severe (CDAI>300) CD, and in high (≥10 mg/L) or low (<10 mg/L) CRP moderate CD subgroups. Placebo-treated CHARM patients were evaluated for disease activity over time and time to CD-related hospitalization, by baseline disease severity and CRP. RESULTS Moderate CD patients had the highest clinical remission rate and largest treatment effect size compared with placebo at week 4 after 160/80 mg induction (46.3% adalimumab, 17.4% placebo; versus 22.9%, 3.6% for severe patients). Moderate-CD/high-CRP patients had the most pronounced efficacy (57.1% adalimumab, 6.7% placebo; versus 40.7%, 20.0% for lower CRP group). Adalimumab maintenance treatment (40 mg every-other-week) achieved superior remission versus placebo at one year in moderate (32.9% versus 13.7%) and severe (27.2% versus 7.5%) cohorts. Among moderate patients, efficacy was similar by CRP category. Moderate-CD/high-CRP placebo-treated patients experienced disease activity and hospitalization rates at week 56 of CHARM approaching those of severe CD patients. CONCLUSIONS This analysis suggests that moderate CD patients can be treated effectively with adalimumab, and supports using CRP to identify moderate CD patients at greatest risk of disease progression.