Effect of teriparatide on bone mineral density and biochemical markers in Japanese women with postmenopausal osteoporosis: a 6-month dose-response study
The dose-response efficacy and safety with three doses of teriparatide and placebo was assessed, using oncedaily subcutaneous injections for 24 weeks, in Japanese postmenopausal women with osteoporosis at high risk of fracture for reasons of preexisting fracture(s), advanced age, and/or low bone mineral density (BMD). In this multicenter, randomized, placebo-controlled study, 159 subjects were randomized and 154 subjects were included for analysis. Teriparatide (10-μg, 20-μg, and 40-μg doses) showed a statistically significant increase with increasing treatment dose as assessed by the percent change of lumbar spine BMD from baseline to endpoint using Williams’ test when compared with placebo (P < 0.001). The mean (±SD) percent change in lumbar spine, femoral neck, and total hip BMD with the 20-μg dose from baseline to endpoint was 6.40% ± 4.76%, 1.83% ± 7.13%, and 1.91% ± 3.60%, respectively. Rapid and sustained increases in bone formation markers [type I procollagen N-terminal propeptide (PINP), type I procollagen C-terminal propeptide (PICP), and bone-specific alkaline phosphatase (BAP)], followed by late increases in a bone resorption marker [type I collagen cross-linked C-telopeptide (CTX)], were observed for the teriparatide treatment groups (20-μg, 40-μg), suggesting a persistent, positive, balanced anabolic effect of teriparatide. Optimal adherence was achieved by this daily self-injection treatment. Regarding safety, most of the adverse events were mild to moderate in severity. No study drug-or study procedure-related serious adverse events were reported during the treatment period. These results observed in Japanese patients may support the observation that teriparatide stimulates bone formation in patients with osteoporosis at a high risk of fracture.