Background IL-6 and TNF-α play critical roles in inflammation of rheumatoid arthritis (RA). Antibodies against these cytokines, biologics, show strong anti-inflammatory effects and have changed the therapy of RA dramatically, but precise mechanisms how they work at the sites of inflammation are remain uncertain. After starting the biologics therapy, anti-rheumatic drugs such as methotrexate (MTX) and prednisolone (PSL) were kept continued. During treatments with biologics, however, we found anti-rheumatic drugs could be stopped specially in treatment with tocilizumab (TCZ) without recurrence of RA. The present study was carried out to compare the decrease in disease modifying anti-rheumatic drug (DMARD) and PSL during biologics.

Objectives The present study was carried out to compare the decrease in disease modifying anti-rheumatic drug (DMARD) and PSL during biologics.

Methods Japanese patients with high disease activity (DAS28 over 6.0) who have not obtained enough response by DMARD and PSL received biologics. After starting biologics, TCZ (8mg/kg), infliximab (IFX, 3mg/kg), and etanercept (ETA 25mg/body), the dose of DMARD and PSL were examined before starting biologics, 1 and 3 years later. When the patients received the biologics at the hospital, clinical assessments and blood tests were also carried out and compared retrospectively. The patients who could not achieve DAS28 remission by biologics in one year were excluded in the present study. The patients treated with adalimumab were not examined because of anti adalimumab antibody in Japanese.

Results More than 150 patients were examined in the present study. Before starting biologics, the doses of MTX and PSL in patients treated with TCZ were as much as those in patients treated with IFX and ETA. At beginning biologics, however, half of patients treated with TCZ but not IFX or ETA stopped MTX as reported (1, 2). In one year, most of the patients achieved DAS28 remission either by TCZ, IFX, or ETA. Thereafter, we gradually decreased the dose of MTX and PSL in these patients. In patients treated with TCZ, DAS28 did not elevate significantly and the dose of MTX and PSL could be tapered. In contrast, the dose of MTX and PSL could not decrease in most of patients treated with IFX and ETA. When the dose of MTX and PSL were decreased, the levels of CRP and DAS28 were elevated in these patients. In two years, both MTX and PSL were stopped in 1/3 of patients treated with TCZ (TCZ monotherapy). They kept remission thereafter (for more than 3 years).

Conclusions These results show the possibility of monotherapy by TCZ but not by IFX or ETA even in RA patients with high activities. Indeed it is suggested that IL-6 and TNF-α have similar effects on inflammation of RA but the different roles exist between IL-6 and TNF-α in RA inflammation.

1. Nishimoto N, et al. Study of active controlled monotherapy used for rheumatoid arthritis, an IL-6 inhibitor (SAMURAI): evidence of clinical and radiographic benefit from an x ray reader-blinded randomised controlled trial of tocilizumab.Ann Rheum Dis. 2007 Sep;66(9):1162-7.

2. Jones G, et al. Comparison of tocilizumab monotherapy versus methotrexate monotherapy in patients with moderate to severe rheumatoid arthritis: the AMBITION study.Ann Rheum Dis. 2010 Jan;69(1):88-96.

Disclosure of Interest None Declared