Presentation (CTI)

OBJECTIVES: Off-label dose escalation of infliximab—through dose increase, interval shortening, or both—is commonly used to manage loss of response in patients with inflammatory bowel disease (IBD) and rheumatoid arthritis. Real world evidence describing the frequency and patterns of treatment intensification remains limited.
This study aimed to quantify the prevalence of infliximab dose intensification over a 10 year period using claims data from a private health insurer in Ireland and determining the proportion of patients receiving doses exceeding 400 mg (assuming a standard dose of 5 mg/kg for an 80 kg patient).
METHODS: A retrospective longitudinal analysis was conducted using a real world claims dataset. For each patient, treatment Cycle 3 was defined as the baseline. All subsequent cycles were evaluated for: (1) dose increase relative to baseline, (2) infusion interval shortening relative to baseline, and (3) concurrent dose increase and interval shortening. Incidence proportions were calculated at the patient level. Secondary analyses examined the maximum dose administered per patient across their treatment course.
RESULTS: Among 1,954 patients who received at least one infliximab infusion, 1,592 received three or more cycles and were included in the primary analysis. Dose increases occurred in 46.0% of patients, interval shortening in 38.3%, and concurrent dose and interval modification in 18.3%. Overall, 65.8% of patients experienced at least one form of treatment intensification (all p < 0.05). In the secondary analysis, 1,126 patients (57.6%) received doses exceeding 400 mg at least once during treatment, with a maximum observed dose of 1,600 mg.
CONCLUSIONS: Infliximab treatment intensification is widespread in clinical practice and is not confined to individual centres. The majority of patients experienced off label dose modification, including substantial escalation beyond standard dosing thresholds. These findings highlight the need for further evaluation of clinical and economic impacts of dose escalation and exploration of strategies such as therapeutic drug monitoring to optimise treatment.