Denosumab: A New Injectable Treatment for Postmenopausal Osteoporosis

Abstract

Background/Introduction:

Osteoporosis results in a significant increase in fractures, leading to morbidity and mortality. Adherence is a concern with commonly used antiresorptive agents, the bisphosphonates. Denosumab, which inhibits bone resorption by a different mechanism and is administered subcutaneously every 6 months, may provide an advantage in decreasing fracture risk in those with osteoporosis.

Objective:

To review the available data with respect to the mechanism of action, efficacy and safety of denosumab for the management of postmenopausal osteoporosis.

Methods:

Several databases were searched to identify phase III randomized controlled trials (RCT) that examined the effect of denosumab on bone mineral density (BMD) and/or fracture rate and the safety of denosumab in the management of postmenopausal osteoporosis.

Results:

In 2 of the 4 trials identified, denosumab was significantly better than placebo at increasing BMD, and in 1 trial reduced the risk of vertebral, nonvertebral and hip fractures. No head-to-head trials comparing fracture risk reduction of denosumab to bisphosphonates were found, however, 2 trials did report increased BMD with denosumab compared to alendronate. In the 4 studies reviewed, adverse effects reported more frequently with denosumab included rash and eczema, as well as bronchitis and influenza-like illness. There is potential for an increased risk of other infections and malignancies.

Conclusions:

The results of RCT trials suggest that denosumab is effective at maintaining or increasing BMD compared to placebo or alendronate in women with either osteopenia or osteoporosis and in 1 trial demonstrated a significant reduction in fracture rate compared to placebo. Overall, denosumab appeared to be well tolerated in the studies reviewed. Continued monitoring is needed to determine long-term safety and efficacy.