Engelke K et al. – ONO–5334 inhibits cathepsin K and has been shown to increase areal BMD at the hip and spine in postmenopausal osteoporosis. Quantitative computed tomography allows the study of the cortical and trabecular bone separately and provides structural information such as cortical thickness. Over two years ONO–5334 showed a statistically significant and persistent increase of trabecular and integral BMD at the spine and the hip. Cortical BMD also progressively increased but at a lower rate. Changes in bone size and of periosteal apposition were not observed.