Is mizoribine a new therapeutic agent for Sjögren's syndrome?

In a multicenter, open-label study conducted in Japan between July 2004 and May 2005, Nakayamada et al. tested the safety and efficacy of mizoribine for the treatment of primary Sjögren's syndrome (pSS). Mizoribine 50 mg was administered three times a day for 16 weeks to 59 patients with pSS, 7 of whom withdrew because of adverse drug reactions; however, no serious adverse events were noted. In the 48 patients who completed the study, an increase from baseline in median salivary secretion volume, evaluated using the Saxon test, was apparent at week 8 and was significant at week 16 (P <0.05). At 16 weeks, significant improvements from baseline were also seen in patients' assessments of dry mouth and dry eyes, physicians' assessment of oral sicca symptoms, labioangular sicca symptoms and physicians' overall assessment, all measured using a 10 cm visual analog scale. The findings suggest that mizoribine could be an effective treatment for pSS.