Treatment with romosozumab increased spine and hip bone mineral density (BMD) and reduced bone resorption in men with osteoporosis and was also well tolerated, according to new findings in The Journal of Clinical Endocrinology & Metabolism.
Romosozumab is a humanized monoclonal antibody that has demonstrated efficacy in the treatment of postmenopausal women with low bone mass in a phase 2 study and in a phase 3 trial with women who had osteoporosis. The current phase 3 trial evaluated the safety and efficacy of romosozumab in men with osteoporosis and randomly assigned 245 participants to either romosozumab 210 mg subcutaneously every month (n=163) or placebo (n=82) for 12 months.
At month 12, the mean change in percentage of BMD in the lumbar spine was significantly higher in the romosozumab group vs the placebo group (12.1% vs 1.2%; P <.001), as well as in total hip (2.5% vs –0.5%; both P <.001). In a bone biopsy substudy that included 20 participants (n=11, romosozumab; n= 9, placebo), histomorphometric analyses at 12 months showed that there was a reduction in bone resorption. This was consistent with findings observed in the previous studies, which included post-menopausal women. The incidence rate of treatment-emergent adverse events was similar in both groups; 75.5% in the romosozumab group and 80.2% in the placebo group, and incident fractures occurred in 3 (1.8%) participants in the romosozumab group vs 2 (2.5%) in the placebo group.
With its dual effect of increasing bone formation and decreasing bone resorption, romosozumab “appears to be a new, promising bone-forming treatment for men with osteoporosis,” wrote the investigators, noting that this dual effect is unique to romosozumab and “has not been observed with any other agent approved for the treatment of osteoporosis.”
Lewiecki EM, Blicharski T, Goemaere S,et al. A phase 3 randomized placebo-controlled trial to evaluate efficacy and safety of romosozumab in men with osteoporosis [published online June 20, 2018]. J Clin Endocrinol Metab. doi:10.1210/jc.2017-02163