To review the frequency with which anti-TNF-α loses its effect and dose "intensification" is required for Crohn's disease (CD) treatment.
Electronic databases were searched for eligible studies. Raw data from studies meeting inclusion criteria were pooled for effect estimates. Subgroup analyses were performed for exploration of heterogeneity regarding all outcomes.
Eighty-six eligible studies were included. Estimates of loss of response (LOR) incidence ranged from 8 to 71%. The random effects pooled incidence of LOR with a median follow-up of 1-year was 33% (95% CI 29-38, 55 studies, n = 6135). The effect estimate based on data from patients with infliximab was 33% (95% CI 27-40), 30% (95% CI 22-39) for adalimumab, and 41% (95% CI 30-53) for certolizumabpegol. Overall, the mean percentage of patients' LOR to anti-TNFs was 38.5%. The annual risk for LOR was 20.9% per patient-year. The random-effects pooled rate of need for dose intensification with a median follow-up of 1 year was 34% (95% CI 28-41, 38 studies, n = 10,690). The effect estimate for infliximab was 38% (95% CI 28-50), 36% (95% CI 30-43) for adalimumab, and 2% (95% CI 2-3) for certolizumab-pegol. The mean percentage of patients who needed an anti-TNF dose escalation was 23% with an annual risk of 18.5% per patient-year. There was no evidence of publication bias for incidence of LOR but not for the dose intensification (p = 0.001).
Overall, around one-third of CD patients experience a LOR and required dose intensification in primary anti-TNF-α responders.