Background Tocilizumab (TCZ) is a humanized anti-interleukin 6 receptor (IL-6R) monoclonal antibody and it was approved in Japan as an antirheumatic drugs in 2008. Evidence of the efficacy of TCZ in real-world RA patients is still few as compared with tumour necrosis factor (TNF) inhibitors.
Objectives We have tried to evaluate the efficacy of TCZ in patients with RA during the 3 years after an approval in 2008 at Nagasaki prefecture, Japan.
Methods One hundred fifty-two RA patients at Nagasaki prefecture, Japan, who has received 8 mg/kg of TCZ every 4 weeks during 3 years, were consecutively enrolled in this study. Ninety-nine patients had evaluable data for 1 year at present. We have focused on the efficacy of TCZ in the present study trying to evaluate the clinical response of disease activity score (DAS) 28, simplified disease activity index (SDAI), clinical disease activity index (CDAI), Boolean approach and Health Assessment Questionnaire (HAQ) by last observation carried forward (LOCF) methodology toward these 99 patients, respectively.
Results The mean age, disease duration and clinical disease activity at baseline were 58 years-old, 11 years, DAS28-ESR: 5.5, SDAI: 28.7 and CDAI: 25.5, respectively. Fifty-nine percent of the patients had received TNF inhibitors before introduction of TCZ. Although most of the patients were active as well as established disease at baseline, the continuation rate at 1 year was superior as 81.1%. A rate of clinical remission at 1 year of DAS28-ESR, SDAI, CDAI and Boolean-based definition was 49.5%, 17.2%, 13.1% and 13.1%, respectively. There was a clear relation of the rate of clinical remission with shorter disease duration (less than 2 years) or no previous history of TNF inhibitors. Furthermore, low HAQ at baseline was the only variable to be associated with CDAI remission (OR [95% CI]: 0.34 [0.09-0.88], p=0.06) and HAQ remission (OR [95% CI]: 0.17 [0.03-0.50], p<0.01) at 1 year defined by logistic regression analysis.
Conclusions The present study shows an excellent therapeutic efficacy as well as the characterisitic of patients being achieved in remission by TCZ in the real-world clinical practice.
Kawashiri SY, et al. In rheumatoid arthritis patients treated with tocilizumab, the rate of clinical disease activity index (CDAI) remission at 24 weeks is superior in those with higher titers of IgM-rheumatoid factor at baseline. Mod Rheumatol. 2011;21:370-4.
Kawashiri SY, et al. Disease activity score 28 may overestimate the remission induction of rheumatoid arthritis patients treated with tocilizumab: comparison with the remission by the clinical disease activity index. Mod Rheumatol. 2011;21:365-9.
Disclosure of Interest None Declared