Mizoribine (MZR), isolated from culture medium of the mold, is a novel immunosuppressant developed in Japan. It has been used in patients with renal transplantation, lupus nephritis, nephrotic syndrome and rheumatoid arthritis (RA).
To review MZR in regards to mechanism of action, pharmacokinetics, efficacy and safety in the treatment of rheumatoid RA and juvenile idiopathic arthritis (JIA).
The drug MZR inhibits both humoral and cellular immunity in RA patients. It is completely excreted in the urine within 24 h, which contributes to the safety of MZR. A series of multicenter studies indicated that MZR was effective and safe in the treatment of RA. In JIA, however, there are only a few case reports reporting its efficacy and safety.
A double-blinded multicenter study is needed to establish the efficacy, safety and indication of MZR in the treatment of JIA.