This study is evaluating the effects of calcium supplementation on the efficacy and safety of
recombinant parathyroid hormone (ALX1-11) in postmenopausal women with osteoporosis. The
primary objective of this clinical study is to evaluate whether increases in bone mineral
density (BMD) for subjects treated with ALX1-11 and receiving no calcium supplementation are
less than increases in BMD observed for subjects treated with ALX1-11 and receiving calcium
supplementation.