The New England Journal of Medicine on September 11 epublished the results of a trial of more than 4000 postmenopausal women with osteoporosis and a previous fragility fracture, in which a monoclonal antibody made by Thousand Oaks, CA-based Amgen outperformed a commonly used and effective osteoporosis medication in preventing new fractures.
Investigators at the University of Alabama at Birmingham (UAB) randomly assigned the women to two groups. One (n = 2046) received injections of the investigational drug romosozumab, which increases bone formation by binding to and inhibiting sclerostin, a protein that inhibits bone formation. The other group (n = 2047) received weekly oral alendronate for 12 months. Both groups then took alendronate for another 12 months.
At 24 months investigators observed 127 new vertebral fractures (6.2%) in the romosozumab group, while the alendronate group had 243 new fractures (11.9%), a 48% lower vertebral fracture risk for the romosozumab group. The risk of nonvertebral fractures and hip fractures in the romosozumab group were 19% and 38% lower, respectively. Patients receiving romosozumab also had greater gains in bone mineral density than those taking alendronate alone.
Adverse events in the two groups were balanced overall, though investigators found more frequent serious cardiovascular adverse events in the romosozumab group (not a statistically significant difference), a finding that hadn’t been seen in prior studies of romosozumab, according to a UAB release.