Late-Stage Study of Romosozumab in Men Finds It Increases Bone Mineral Density

A 12-month, phase 3 study of romosozumab in men aged 55 to 90 years with osteoporosis found that it increased spine and hip bone mineral density (BMD) and was well tolerated.

Osteoporosis affects 1 to 2 million men in the United States and 5.5 million men in the European Union, the study said. One in 5 men aged 50 years or older is predicted to experience an osteoporotic fracture, according to the study, and 1 in 3 fractures occur in men 60 years or older with a lifetime osteoporosis fracture risk of 15%.

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The morbidity and mortality associated with fracture, in particular hip fracture, are greater for men than for women, the authors found, and they wrote that there is a lack of bone-forming agents for men. However, earlier this year, the United States Preventive Services Task Force (USPSTF) updated its 2011 recommendation about osteoporosis screening and stood by an earlier report that said current evidence is insufficient to assess the risk and benefit of osteoporosis screening in men.

The randomized, double-blind, placebo-controlled BRIDGE study suggested that romosozumab, a humanized monoclonal antibody that binds and inhibits sclerostin, may be a promising bone-forming treatment for men with osteoporosis. Sclerostin, which is secreted by osteocytes, regulates bone formation.

The global BRIDGE study was conducted in 31 centers. Men were included if they had a baseline BMD T-score at the lumbar spine (LS), total hip (TH), or femoral neck of ≤—2.5 or ≤–1.5 with a history of a fragility nonvertebral or vertebral fracture. Patients were randomized 2:1 to receive romosozumab 210 mg subcutaneously monthly or placebo. Of 245 subjects, 163 received romosozumab, 82 received placebo. The primary endpoint was percentage change from baseline in LS BMD at month 12.

At month 12, the mean percentage change from baseline in the LS and TH BMD was significantly greater for the romosozumab group than for the placebo group (LS, 12.1% vs 1.2%; TH, 2.5% vs —0.5%; P < 0.001). Adverse events (AEs) and serious AEs were balanced between the 2 groups, with a numerical imbalance in the positively adjudicated cardiovascular serious AEs [romosozumab, 8 (4.9%) vs placebo, 2 (2.5%)].

Many people will not know they have osteoporosis—a skeletal disorder characterized by loss of bone mass, deterioration of bone tissue, and decline in bone quality&mdash;until they have a fracture. In some cases, fractures can lead to disability, chronic pain, loss of independence, lower quality of life, and even death. About 21% to 30% of patients who experience a hip fracture die within 1 year.

Risk factors for osteoporosis in both men and women include low body weight, excessive alcohol consumption, current smoking, long-term corticosteroid use, previous fractures, and history of falls within the past year.

Reference

Lewiecki EM, Blicharski T, Goemaere S, et al. A phase III randomized placebo-controlled trial to evaluate efficacy and safety of romosozumab in men with osteoporosis. J Clin Endocrinol Metab. 2018;103(9):3183-3193. doi: 10.1210/jc.2017-02163.