Strontium ranelate: vertebral and non-vertebral fracture risk reduction

Abstract

Fractures are common at the spine and hip, but at least half the morbidity and mortality of fractures in the community come from fractures that involve other sites. Over half of all fractures arise in individuals without osteoporosis, whereas the highest risk group for fractures are individuals over 80 years of age. Reducing the burden of fractures should thus include an assessment of drug efficacy against all fractures in a wide range of individuals. For vertebral fractures, in the phase III Spinal Osteoporosis Therapeutic Intervention study of 1649 postmenopausal women with osteoporosis, 2 g strontium ranelate a day produced a risk reduction of 49% in the first year and 41% during 3 years. In the TReatment Of Peripheral OSteoporosis study, which was designed to examine the effect of strontium ranelate on non-vertebral fractures, of the 5091 patients, 3640 had spine X-rays. The vertebral fracture risk reduction was 45% at one year and 39% over 3 years. In a preplanned pooling of the above two studies, 1170 patients had vertebral osteopenia. Strontium ranelate reduced the risk of vertebral fracture in 3 years by 40% in these patients. In 409 patients with lumbar or femoral neck osteopenia, strontium ranelate reduced the risk of vertebral fractures by 62% over 3 years. In the pre-planned pooling of data from the two studies, in 1488 women aged between 80 and 100 years (mean age 84 +/- 3 years), the risk of vertebral fractures was reduced in one year by 59% and by 32% over 3 years. For non-vertebral fractures, in the TReatment Of Peripheral OSteoporosis study, treatment for 3 years reduced the fracture risk by 16%, and by 19% for major fragility fractures. In a post-hoc analysis of 1977 women at high risk of hip fracture (aged > or = 74 years and with a femoral neck bone mineral density T-score < or = -2.4) the hip fracture risk was reduced by 36%. In patients aged 80 and over in the pre-planned pooling of data from the two studies, the risk of an incident non-vertebral fracture was reduced by 41% in the first year and by 31% over 3 years. Strontium ranelate, a new anti-osteoporosis agent, has a broad range of antifracture efficacy.