[Development of hPTHrP (1-36) as an anabolic therapeutic agent for osteoporosis]

Parathyroid hormone-related protein (PTHrP) shares the same receptor (PTH/PTHrP recoptor) with parathyroid hormone (PTH) to generate common intracellular signals. Thus, systemic actions of PTHrP are seemed to be essentially the same as those of PTH, although PTHrP plays its physiological roles in cartilage development and smooth muscle contraction as a local factor. Subcutaneous administration of PTH once a day demonstrates anabolic effects on bone and has been established to be an effective therapeutic modality for patients with severe osteoporosis to increase bone mineral density and then prevent fracture substantially. According to preclinical and some clinical data, daily subcutaneous injection of human PTHrP (1-36) could stimulate bone formation without a substantial increase in bone resorption or expected adverse events such as hypercalcemia. Thus, human PTHrP (1-36) is one of the promising drugs for treatment of osteoporosis.