Prolia (denosumab) superior to zoledronic acid in gains for bone mineral density according to phase IV study in postmenopausal osteoporosis- Amgen

Amgen has announced findings from a randomised, double-blind, double-dummy, multicentre Phase IV study showing that Prolia (denosumab) achieved greater gains in bone mineral density (BMD) than the intravenous bisphosphonate zoledronic acid (Zometa) in postmenopausal women with osteoporosis following previous treatment with oral bisphosphonates. The findings were presented at the American Society for Bone and Mineral Research (ASBMR) 2015 Annual Meeting in Seattle.

The 12-month study (NCT01732770) included 643 women 55 years or older who had postmenopausal osteoporosis (BMD T-score -2.5 or less at the lumbar spine, total hip, or femoral neck) and had been taking oral bisphosphonate therapy for two or more years. The women were randomised 1:1 to receive either subcutaneous denosumab (60 mg) every six months plus intravenous placebo once yearly (denosumab group, 321 participants), or intravenous zoledronic acid (5 mg) once yearly plus subcutaneous placebo every six months (zoledronic acid group, 322 participants). The change from baseline in lumbar spine BMD at 12 months – the primary endpoint – in the denosumab group was significantly greater than that in the zoledronic acid group: 3.2% vs. 1.1%, respectively (p<0.0001). The denosumab group also had significantly greater improvements than the zoledronic acid group in secondary and exploratory study endpoints, including BMD changes in the total hip (1.9% vs. 0.6% [p<0.0001]), femoral neck (1.2% vs. -0.1% [p<0.0001]), and 1/3 radius (0.6% vs. 0.0% [p<0.0184]).

Comment: Lead investigator Paul Miller, medical director of the Colorado Center for Bone Research, commented "Despite the availability of newer therapies like denosumab, bisphosphonates are commonly used first-line to treat osteoporosis. Our findings showed that denosumab provides significantly greater bone mineral density increases than zoledronic acid."