Dose Intensification with Infliximab in Patients with Rheumatoid Arthritis

BACKGROUND: Infliximab, in combination with methotrexate, is indicated for the treatment of moderate to severe active rheumatoid arthritis (RA). While there is anecdotal evidence that many patients beginning infliximab therapy have their dose and/or frequency of infusions increased over time ("dose intensification"), relatively little is known about actual patterns of use in clinical practice. OBJECTIVE: To examine patterns of infliximab use in patients with RA. METHODS: Using a large US healthcare claims database, all patients with RA who initiated infliximab therapy between January 1, 2000, and September 30, 2001, were identified. The date of each patient's first claim for infliximab was identified and designated as the index date; attention was limited to patients who received infliximab for at least one year. Patterns of infliximab use were then examined over the 12-month period following the index date, based on information on paid claims. RESULTS: Fifty-three patients met all entry criteria; the mean age was 61 years, and 81% were women. Twenty-eight percent of patients received >8 infusions over 12 months. The mean dose of infliximab at initial infusion was 296.2 mg; at final infusion, it was 401.9 mg (36% increase). One-half of study subjects had their dose of infliximab increased by > or =30% between the initial and final infusions; one-third had their dose increased by > or =50%. CONCLUSIONS: Many patients with RA beginning treatment with infliximab have their frequency of infusions and/or medication dose increased within the first 12 months.