Tocilizumab is effective in the treatment of rheumatoid arthritis (RA). A proportion of patients achieve low disease activity using a lower than registered starting dose. We investigated the feasibility of dose reduction to 4 mg/kg in patients who reached low disease activity at the registered dose of 8 mg/kg.
In this retrospective study, data were collected of 22 patients successfully treated with tocilizumab 8 mg/kg for about 6 months and tapered to 4 mg/kg because of low disease activity. In case of loss of disease control, the dose could be increased again to 8 mg/kg. The percentage of patients with successful dose reduction and difference in DAS28 was described.
Mean DAS28 at time of dose reduction was 2.3 (SD 0.9). After 3 and 6 months follow-up, 77% (95% CI 54-91) and 55% (95% CI 32-76) of patients had successfully reduced the dose without losing disease control, respectively. DAS28 at 3 and 6 months was somewhat higher than baseline, 2.7 (SD 1.2) and 2.5 (SD 1.0) respectively. All patients who experienced worsening of disease activity after dose reduction regained low disease activity after dose escalation.
Dose reduction of tocilizumab seems feasible in a substantial proportion of patients. Dose escalation after flare was effective in all patients.