THOUSAND OAKS (dpa-AFX) - Amgen (AMGN) announced findings from a randomized, double-blind, double-dummy, multicenter Phase 4 study showing that Prolia or denosumab achieved greater gains in bone mineral density or BMD than the intravenous bisphosphonate zoledronic acid in postmenopausal women with osteoporosis following previous treatment with oral bisphosphonates.
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 randomized 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 percent vs. 1.1 percent, 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 percent vs. 0.6 percent [p<0.0001]), femoral neck (1.2 percent vs. -0.1 percent [p<0.0001]), and 1/3 radius (0.6 percent vs. 0 percent [p<0.0184]).
In the study, no new safety signals were identified. The two study groups had similar incidences of overall adverse events or AEs, serious AEs, AEs leading to discontinuation, and fatal AEs. Three events consistent with the definition of atypical femoral fracture were observed, including two in the denosumab group and one in the zoledronic acid group. There were no cases of osteonecrosis of the jaw or ONJ, hypocalcemia, or delayed fracture healing.
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