A multicenter randomized double-masked comparative study of different preparations of alendronate in osteoporosis – monthly (four weeks) intravenous versus once weekly oral administrations

Abstract

Objective:The aim of this study was to evaluate the efficacy and safety of intravenous alendronate (ALN) 900 µg every 4 weeks compared to oral ALN 35 mg once weekly.Methods:A 52-week, multicenter, randomized, double-masked, active-controlled, parallel-group, non-inferiority study was conducted in a total of 325 Japanese patients aged 48–87 years with osteoporosis. Patients were randomly assigned to an intravenous ALN (iv, n = 162) group or oral ALN (po, n = 163) group. The efficacy of the both formulations was assessed primarily by bone mineral density (BMD) measurement.Results:The percentage BMD change from baseline in lumbar spine (L2–L4) after 52 weeks of treatment was 6.4 ± 0.3% in the iv group and 6.0 ± 0.3% in the po group (least-squares mean ± SE). The inter-group difference in least-squares mean of percentage change from baseline in BMD was 0.37%, and its 95% confidence interval was −0.47% to 1.20%. The non-inferiority of the iv group was established against the po group with a prespecified non-inferiority margin (Δ) of 1.5%. In addition, the four bone turnover markers were reduced to a similar level by either treatment throughout the treatment period. The safety profile was also similar between the two treatment groups. Because of the limitations presented in this study, the results of the iv group may not apply to non-Japanese patients with osteoporosis.Conclusions:The efficacy and safety of the intravenous ALN 900 µg once every 4 weeks were similar to those of the oral ALN 35 mg once weekly, indicating that intravenous administration of ALN is an effective treatment for osteoporosis and will provide a useful alternative to oral dosing.