A systematic review on the use of daily subcutaneous administration of teriparatide for treatment of patients with osteoporosis at high risk for fracture in Asia
PURPOSE Intermittent administration of recombinant human PTH [rhPTH (1-34)] exerts an osteoanabolic effect characterized by direct effects on bone formation, increases bone density, and reduces fracture risk. This study was to investigate the anabolic effects of rhPTH(1-34) on postmenopausal osteoporosis in an Asian population and compare the time course and alteration in bone turnover marker (BTM) during rhPTH(1-34) and elcatonin treatment. METHODS 124 women with postmenopausal osteoporosis were enrolled in this prospective, open-label, active-controlled trial. The patients randomized to subcutaneous rhPTH(1-34) (20 ug, once daily) or elcatonin (200U, once week) injections for 12 months. Biochemical markers of bone formation (bone specific alkaline phosphatase [BSAP]), and bone resorption maker (serum C-telopeptide of type I collagen [CTX-I] were measured at baseline and at 0, 6, and 12 months. RESULTS At 12 months, rhPTH (1-34) significantly increased lumbar spine BMD significantly compared with baseline, whereas elcatonin was ineffective. BSAP levels were gradually increased in almost all rhPTH(1-34)-treated subjects and at the end of the study, the percentage of subjects with BSAP above the postmenopausal reference interval was gradually increased as high as 91.5% at month 12. Opposite trends in percentages for CTX-I was observed in rhPTH(1-34). With rhPTH(1-34), but not elcatonin, there were significant positive correlations between ratio of BSAP and CTX-I and bone mineral density (BMD) (r=0.318) at the end of month 12. Both treatments were well tolerated and there were no significant differences detected between the 2 groups in the proportion of any adverse events and any serious adverse events. CONCLUSIONS rhPTH (1-34) has more positive effects on bone formation than elcatonin for postmenopausal women with osteoporosis and was proved to be safe and well tolerated. The ratio of BSAP and CTX-I may be a useful indicator for positive bone formation.