Therapeutic effects of alendronate 35 mg once weekly and 5 mg once daily in Japanese patients with osteoporosis: a double-blind, randomized study

The efficacy and safety of treatment with oral alendronate (ALN) 35 mg once weekly for 52 weeks were compared with those of ALN 5 mg once daily in a double-blind, randomized, multicenter study of Japanese patients with involutional osteoporosis. The primary efficacy end point was the percent change from baseline in the lumbar spine (L1-L4) bone mineral density (BMD) after 52 weeks of treatment. In this study, 328 patients were randomized to ALN 5 mg once daily (160 patients) or ALN 35 mg once weekly (168 patients). The adjusted mean percent change from baseline in lumbar spine (L1-L4) BMD after 52 weeks of treatment was 5.8% and 6.4% in the once-daily group and the once-weekly group, respectively (both P < 0.001). The 95% confidence interval for the difference in spine BMD change between the two treatment groups was -0.31% to 1.48%, indicating that the two regimens were therapeutically equivalent, since the confidence interval fell entirely within the predefined equivalence criterion (+/-1.5%). The time course of the spine BMD increase was also similar for both regimens. Regarding total hip BMD, mean changes from baseline at 52 weeks were 2.8% and 3.0% in the once-daily group and the once-weekly group, respectively. In addition, the bone markers (urinary deoxypyridinoline, urinary type-I collagen N-telopeptides, and serum bone-specific alkaline phosphatase) were reduced to a similar level by either treatment throughout the treatment period. The tolerability and safety profiles were also similar between the treatment groups. Taken together, we conclude that the efficacy and safety of the ALN 35-mg once-weekly regimen are therapeutically equivalent to those of the ALN 5-mg once-daily regimen.