Systematic review and meta-analysis: evaluating response to empiric anti-TNF dose intensification for secondary loss of response in Crohn’s disease

INTRODUCTION: Anti-tumor necrosis factor (TNF) dose intensification represents an effective method of overcoming secondary loss of response (LOR); however, a subset of patients may not respond (tertiary non-response), or fail to demonstrate durable response (tertiary LOR) to intensified dosing. This systematic review and meta-analysis aimed to evaluate these outcomes to determine the clinical effectiveness of empiric dose intensification in Crohn’s disease. METHODS: Multiple databases including MEDLINE and EMBASE were interrogated to identify studies that reported outcomes following anti-TNF dose intensification to address secondary LOR in Crohn’s disease. Studies that used anti-TNF levels as the primary basis for dose intensification were excluded. Studies that reported (1) tertiary response and tertiary non-response within 6 months or (2) tertiary response and tertiary LOR beyond 6 months, were pooled using a random effects model with risk ratio (RR) derived, quantifying the effect of each comparison. RESULTS: Twenty-six studies reported outcomes following anti-TNF dose intensification to address secondary LOR. Short-term response within 12 weeks of any dose-intensification strategy was 33–90%, while sustained response (⩾48 weeks) was achieved in 25–85%. Tertiary non-response occurred in up to 45% of intensified patients within 6 months of anti-TNF dose intensification, while tertiary LOR beyond 6 months occurred in up to 64% of patients. Tertiary response was more likely than tertiary non-response within 6 months (RR 2.58, 95% CI (1.76, 3.79), I(2) = 82%, 12 studies), while sustained response beyond 6 months compared to tertiary LOR (RR 1.10 (0.75, 1.61) I(2) = 85%, 7 studies) was less convincing. CONCLUSION: Although anti-TNF dose intensification is clinically effective in patients with Crohn’s disease, particularly within the first 6 months, a proportion of patients will fail to demonstrate short-term and/or sustained clinical response. Hence, clinical reassessment following anti-TNF dose intensification, particularly beyond 6 months, remains important to differentiate between effective and ineffective dose-intensification strategies.