The effectiveness of new triple combination therapy using synthetic disease-modifying anti-rheumatic drugs with different pharmacological function against rheumatoid arthritis: the verification by an in vitro and clinical study

The study aims to confirm the feasibility of new oral triple combination therapy using methotrexate (MTX), mizoribine (MZR), and tacrolimus (TAC) in patients with rheumatoid arthritis (RA) by in vitro and clinical analyses. Triple therapy with a combination of MTX, MZR, and TAC was used for an in vitro study with osteoclasts and a prospective clinical study in order to show the efficacy of these agents against refractory RA. In particular, low-dose TAC or MZR was added to treat 14 patients with RA that was resistant to MTX + MZR or MTX + TAC dual therapy. The combination of three pharmacological agents showed statistically significant differences to reduce differentiation induction and activity of osteoclasts compared with single and double agents. In clinical use, triple therapy showed a statistically significant difference in the improvement of Disease Activity Score-28-erythrocyte sedimentation rate and the Simple Disease Activity Index score at around 8 months. Additionally, the serum matrix metalloproteinase-3 level significantly decreased. No patients dropped out because of adverse effects. Based on this in vitro and prospective clinical study, oral triple therapy might be effective against refractory RA. Furthermore, this therapy might be safe and economical for clinical practice.