Outcomes of infliximab dose escalation in patients with rheumatoid arthritis

Dose escalation of infliximab in both primary and secondary nonresponders is widely reported; however, the usefulness of dose escalation has been disputed. The objective of this analysis is to evaluate trends in clinical efficacy following multiple infliximab dose escalations in patients with rheumatoid arthritis (RA).

Patients enrolled in a US RA registry were included if they initiated infliximab at 3 mg/kg every 8 weeks, received ≥ 1 infliximab dose escalation within 12 months of initiation, and had ≥ 1 visit following dose escalation. Trends in mean Clinical Disease Activity Index (CDAI) and Health Assessment Questionnaire (HAQ) scores from visits following dose escalations were evaluated.

In patients who received 2 or 3 dose escalations, the initial (1 or 2) dose escalations resulted in reduced mean CDAI scores, but subsequent escalations did not further reduce disease activity. In patients who received ≥ 4 dose escalations, mean CDAI scores did not further reduce disease activity over time. Mean HAQ scores were stable over time in patients who received 2 or 3 dose escalations. In patients who received ≥ 4 dose escalations, mean HAQ scores decreased following 1 dose escalation but progressively increased following subsequent dose escalations.

Initial dose escalations (from 3 mg/kg to the equivalent of approximately 5 to 7 mg/kg) may be useful in controlling disease activity; however, there may be diminishing clinical benefit of further escalations, which can also increase the potential risk for infection and increase incremental drug costs.

• Initial infliximab dose escalations (1 to 2) may be useful in lowering disease activity in patients with rheumatoid arthritis. • There does not appear to be a clinical benefit in infliximab dose escalations above the equivalent of 5 to 7 mg/kg.