Retrieval of serum infliximab level by shortening the maintenance infusion interval is correlated with clinical efficacy in Crohns disease
Inflammatory Bowel Disease, 04/24/2012  Clinical Article

Hibi T et al. – A treatment strategy with an option of shortening the dosing interval of infliximab retrieves its trough level and may be useful for maintaining its efficacy.

• This was an open–label prospective multicenter study.
• Infliximab was administered at 5 mg/kg to patients with active CD at weeks 0, 2, and 6.
• Week 10 responders received infliximab every 8 weeks thereafter.
• In those with loss of response after week 14 the interval was switched to every 4 weeks.
• Co–primary endpoints were the rate of patients achieving clinical response and remission at week 54.
• Serum level of infliximab was measured at each visit.

• Fifty–seven patients who responded to induction treatment received maintenance therapy after week 14.
• Thirty–seven patients continued at the 8–week interval and 20 patients were switched to a 4–week interval.
• The overall clinical response and remission rates at week 54 were 82.5% and 61.4%, respectively.
• For those with loss of response, treatment at the 4–week interval resulted in clinical response and remission rates of 83.3% (15/18) and 55.6% (10/18), respectively, at week 54.
• A correlation between clinical efficacy and serum trough level was found (P < 0.01, overall).