Effects of YM529, a novel minodronic acid, on adjuvant arthritis in rats.

OBJECTIVE The effects of a new third-generation bisphosphonate, YM529, on both the development and treatment of adjuvant arthritis were investigated in rats. METHODS Five-week-old Lewis rats with adjuvant arthritis were prophylactically and therapeutically treated with 0.001, 0.01 and 0.05 mg/kg/day of YM529 and the arthritis scores were measured. Soft X-ray and histological finding were compared to those of the control group. Body weights were also measured. RESULTS YM529 suppressed the severity of adjuvant arthritis in a dose-dependent manner when used as either a prophylactic or therapeutic drug. Administration of the drug had little effect on body weight. CONCLUSION YM529 may act on arthritic joints locally to prevent inflammation. However, further experiments are necessary to elucidate the underlying mechanisms.