NCT00851565.

Combined measurements of infliximab and anti-infliximab antibodies using cut-off levels provided high accuracy for discriminating between clinical response types to infliximab maintenance therapy. Cut-off levels are considered a prerequisite to further investigations of clinical usefulness of measurements of infliximab and anti-infliximab antibodies in patients failing infliximab therapy.

Dose intensification leads to a sustained regained response in 47% of CD patients who lost response to standard infliximab dose, but halving the infusion intervals is probably not superior to dose-doubling. Given the costs and patient inconvenience incurred by an additional infusion visit, the dose-doubling strategy may be preferable to the interval-halving strategy.

Despite variable analytical properties, common assays result in similar classifications and interventions in patients with IFX treatment failure, and with comparable clinical outcomes. Implications are, however, profound for the minority classified differently.