Background For active rheumatoid arthritis patients with inadequate response to synthetic disease modifying antirheumatic drugs (DMARDs), biologic agents are indicated. However, the cost of biologics, including tocilizumab, is very high, which makes it difficult for all patients to receive biologics because of the associated expenses.
Objectives A period of 4 weeks has been recommended as the interval between tocilizumab infusions in active rheumatoid arthritis patients. In our clinical experience, we observed that longer intervals could also be effective. The aim of the present study was to clarify the efficacy of tocilizumab infusion at 5 weeks and 6 weeks intervals in active rheumatoid arthritis patients.
Methods The rheumatoid arthritis patients who showed inadequate response to synthetic DMARDs and the patients who showed inadequate response to TNF inhibitors and who agreed with tocilizumab therapy of six weeks interval were enrolled in the present study. Initially, active rheumatoid arthritis patients were infused with 8 mg/kg of tocilizumab every 6 weeks with oral medicines. For patients who did not achieve clinical remission with tocilizumab infusions at 6 weeks intervals, the doses of the oral medicines were increased. The patients who did not achieve clinical remission after another 6 months of tocilizumab infusions at 6 weeks intervals were administered tocilizumab infusions every 5 weeks or 4 weeks, along with the same doses of the oral medicines.
Results Among 100 patients enrolled, 60 achieved clinical remission with 6 weeks interval, 19 with 5 weeks interval, and 5 with 4 weeks interval of tocilizumab infusions. Ten patients did not achieve clinical remission. Six patients dropped out from the study because of personal reasons. In patients who achieved remission with tocilizumab infusion at 6 weeks interval, the disease activity parameters at baseline were significantly lower than those with tocilizumab infusion at 4 weeks interval. Severe adverse events that led to the discontinuation of treatment, including tuberculosis and death, did not occur, and the frequency of other adverse events with infusions at 6 weeks intervals was lower than that at 4 weeks intervals.
Conclusions The present study has provided evidence that tocilizumab infusions at 4 weeks interval and 6 weeks intervals may be effective in active rheumatoid arthritis patients. This finding should be of great interest for patients for both financial and labor reasons.
Disclosure of Interest None declared