Efficacy of once-weekly teriparatide for primary prevention of glucocorticoid-induced osteoporosis: A post hoc analysis of the TOWER-GO study

Objectives A post hoc analysis of the Teriparatide Once-Weekly Efficacy Research for Glucocorticoid-induced Osteoporosis (TOWER-GO) study was performed to examine the effect of once-weekly administration of 56.5 mu g teriparatide on primary prevention of glucocorticoid-induced osteoporosis (GIOP). Methods Of the subjects of the TOWER-GO study, 73 were included. The percentage changes from baseline in lumbar spine bone mineral density (BMD) and bone turnover markers were evaluated over 72 weeks with once-weekly teriparatide and once-weekly alendronate. Results The percentage change of lumbar spine BMD from baseline at 72 weeks was significantly increased in both groups. Bone formation markers were significantly increased by teriparatide administration, although they were slightly decreased by alendronate administration. Bone resorption markers were gradually decreased by teriparatide, whereas alendronate markedly decreased them within 4 weeks. No major safety concerns arose. Conclusions In this primary prevention study of GIOP, comparable increases in BMD were observed between alendronate and once-weekly teriparatide. More desirable changes in bone markers were observed with teriparatide administration. These data suggest that once-weekly teriparatide is effective in primary prevention of GIOP.