A phase III clinical trial of monthly minodronate in the treatment of Chinese postmenopausal women with osteoporosis.

To date, monthly oral bisphosphonates have not been available in China. In this randomized, double blind, positive-controlled, multicenter phase III clinical trial, we compared the efficacy and safety of monthly minodronate versus weekly alendronate in the treatment of Chinese postmenopausal women with osteoporosis. A total of 548 participants were screened across 31 study centers, of which 330 participants were randomized into two groups: the experimental group (n = 165) received oral minodronate (50 mg/tablet once every four weeks) and alendronate placebo (once weekly), while the positive control group (n = 165) received oral alendronate (70 mg/tablet once weekly) and minodronate placebo (once every four weeks) for a duration of 48 weeks. The bone mineral density (BMD) of the lumbar spine, femoral neck and total hip were measured using dual-energy X-ray absorptiometry (DXA) at baseline and at 24 and 48 weeks. At the end of treatments, the experimental group exhibited a mean increase (SD) in BMD above the baseline at the lumbar spine, femoral neck and total hip of 4.61% (4.613%), 3.04% (4.034%) and 3.40% (3.569%), respectively, compared with those of 4.55% (3.753%), 1.86% (3.592%) and 2.30% (4.838%) in the control group. All improvements from the baseline in the two groups were statistically significant. The monthly minodronate did not cause new safety risks compared with alendronate. This study demonstrates that monthly minodronate administration is non-inferior to weekly alendronate in terms of therapeutic efficacy, while maintaining a comparable safety profile. Furthermore, the monthly dosing schedule of minodronate may significantly enhance medication adherence among osteoporosis patients, potentially improving long-term treatment outcomes.