Protelos: nonvertebral and hip antifracture efficacy in postmenopausal osteoporosis

Strontium ranelate is a new treatment for postmenopausal osteoporosis, simultaneously increasing bone formation and decreasing bone resorption, thus rebalancing bone turnover in favor of bone formation. Strontium ranelate was demonstrated to significantly reduce the relative risk of vertebral fracture whatever the severity of the disease. In the TReatment Of Peripheral OSteoporosis (TROPOS) study, the incidence of nonvertebral and hip fractures, following treatment with strontium ranelate (Protelos, Servier) at a dosage of 2 g/day orally, was assessed over a 3-year period. In this double-blind, placebo-controlled trial, 5091 women with postmenopausal osteoporosis were assigned to either strontium ranelate (n = 2479) or placebo (n = 2453) treatment. Overall, the reduction in risk for nonvertebral fractures in patients treated with strontium ranelate was 16% (P = 0.04) and for major fractures (hip, wrist, pelvis and sacrum, ribs and sternum, clavicle and humerus), it was 19% (P = 0.031), compared with those treated with placebo. Women with osteoporosis and aged 74 years or more who were treated with strontium ranelate (n = 982) had a 36% reduction in risk of hip fracture (P = 0.046) over 3 years compared with those treated with placebo (n = 995). The difference in bone mineral density between groups was 8.2% for femoral neck and 9.8% for total hip at 3 years. The incidence of adverse events was comparable between groups. The study demonstrates that strontium ranelate treatment offers a safe and effective means of reducing the risk of nonvertebral and hip fractures in postmenopausal women with osteoporosis.