Open label study to assess infliximab safety and timing of onset of clinical benefit among patients with rheumatoid arthritis

Objective. To assess the timing of onset of clinical benefit following the initial infusion of infliximab and to obtain additional safety experience of infliximab when given in an office setting to patients with rheumatoid arthritis (RA), In addition, the safety of reducing the infusion time from 2 hours to 1 hour was evaluated. Methods. Patients (n = 553) with active RA despite receiving methotrexate (MTX) were treated with infliximab 3 mg/kg given over 2 h at baseline (Week 0), and Weeks 2, 6, and 14 in this multicenter open-label trial. Patients continued to receive a stable dose of MTX (greater than or equal to 7.5 mg/wk). At selected sites, patients tolerating the first 4 infusions were eligible to receive 2 additional infusions at twice the usual infusion rate (given over 1 h). Patients returned for efficacy assessments at 48 h following the initial infusion and several times throughout study participation. Results. By 48 h following the first infusion, significant (p < 0.001) improvements were observed in duration of morning stiffness (34% mean improvement), physician's global disease assessment scores (30%), patient's global disease assessment scores (25%), and patient's pain assessment scores (30%). By Week 16, 52 to 63% mean improvements in these efficacy variables were observed (p < 0.001); the significant improvement was maintained through the end of study participation in the subset of patients who received the additional 1 h infliximab infusions. Through 16 weeks, 10% (54/553) of patients reported an adverse event associated with at least 1 of the 4 infusion procedures; the majority were mild and transient in nature. In the subset of 197 patients who received 2 additional infusions over 1 h, no increase in the frequency or severity of infusion-related adverse events was observed compared to the 2 h infusion. Conclusion. Infliximab administered to patients with RA in an outpatient setting resulted in significant clinical improvement within 48 h that was sustained with additional infusions. Approximately 10% of patients experienced an infusion reaction, highlighting the need for direct supervision over patient treatment. Patients who tolerated infliximab infusions given over 2 h also tolerated a 1 It infusion.