Long-term intermittent pulse therapy with mizoribine attenuates histologic progression in young patients with severe lupus nephritis: report of two patients.

Mizoribine (MZR), a novel selective inhibitor of inosine monophosphate dehydrogenase in the de novo pathway, whose mode of action is very similar to that of mycophenolate mofetil, has been successfully applied without serious adverse effects for the treatment of renal diseases. We have previously reported the efficacy and safety of a new MZR treatment regimen, namely, oral MZR intermittent pulse therapy, which we examined based on the observation that it might show superior efficacy to the conventional daily low-dose MZR regimen on account of the higher peak serum MZR levels, in selected patients with lupus nephritis. Two Japanese patients with severe lupus nephritis (WHO class IV-G) who were administered long-term intermittent MZR pulse therapy, and in whom pre- and post-treatment renal biopsies were reported. Post-treatment renal biopsy confirmed the marked attenuation of histologic progression by the treatment. These clinical observations may lend further support, from the histologic standpoint, to the efficacy of long-term MZR intermittent pulse therapy for selected patients with active lupus nephritis.