Abstract
BACKGROUND: Osteoporosis medications increase bone-mineral density (BMD) and lower but do not eliminate fracture risk. The combining of anabolic agents with bisphosphonates has not improved efficacy. We compared combined teriparatide and denosumab with both agents alone. METHODS: From September, 2009, to January, 2011, we enrolled postmenopausal women with osteoporosis into this randomised, controlled trial. Patients were assigned in a 1:1:1 ratio to receive 20 μg teriparatide daily, 60 mg denosumab every 6 months, or both. BMD was measured at 0, 3, 6, and 12 months. Women who completed at least one study visit after baseline were assessed in a modified intention-to-treat analysis. This trial is registered with ClinicalTrials.gov, number NCT00926380. FINDINGS: 94 (94%) of 100 eligible women completed at least one study visit after baseline. At 12 months, posterior-anterior lumbar spine BMD increased more in the combination group (9·1%, [SD 3·9]) than in the teriparatide (6·2% [4·6], p=0·0139) or denosumab (5·5% [3·3], p=0·0005) groups. Femoral-neck BMD also increased more in the combination group (4·2% [3·0]) than in the teriparatide (0·8% [4·1], p=0·0007) and denosumab (2·1% [3·8], p=0·0238) groups, as did total-hip BMD (combination, 4·9% [2·9]; teriparatide, 0·7% [2·7], p<0·0001; denosumab 2·5% [2·6], p=0·0011). INTERPRETATION: Combined teriparatide and denosumab increased BMD more than either agent alone and more than has been reported with approved therapies. Combination treatment might, therefore, be useful to treat patients at high risk of fracture. FUNDING: Amgen, Eli Lilly, National Center for Research Resources.