Appropriate disease modifying anti-rheumatic drugs (DMARDs) can inhibit inflammation and improve clinical outcome in RA patients, and we aim at remission with DMARDs for them. Better development for diagnosis tools will be expected, and preventive care, pre-emptive therapy and personalized healthcare will be the next candidates of treatment strategies for the future. However, at this stage, we need to consider the maximization of RA treatment using approved DMARDs.
Methotrexate (MTX), which is one of synthetic DMARDs, is the most frequently used in Japan. Meanwhile, there is possibility of the risk to affect an influence to various organs via MTX using, although MTX remains the "anchor drug" in RA treatment. It is important for us to understand whether the efficacy of biologic DMARDs treatment with MTX is more meaningful or not. We described the efficacy of MTX in combination with TNF inhibitor was superior to that of TNF inhibitor monotherapy in the JESMR study. Additionally, the SURPRISE Study with Tocilizumab (TCZ) which inhibits IL-6 signaling, is a multicenter, prospective, randomized, open-label study compared the MTX plus TCZ with TCZ monotherapy for RA patients who have inadequate response to MTX. The remission rate of combination therapy using DAS28-ESR was higher than that of TCZ monotherapy at 24 weeks. On the other hand, there was no significant difference among two groups at 52 weeks. It suggests TCZ might be able to taper the dose of MTX if remission is achieved with combination therapy after 24 weeks.
So far, we have demonstrated not only clinical data of TCZ, but also translational data using blood samples. Our research suggests the changes of serum cytokine and several subsets of peripheral cells are not the same in RA patients treated with different biological DMARDs.
We will highlight our studies by focusing on the significance of IL-6 inhibition.