Bone Formation-Resorption Coupling and Osteoporosis

This is a randomized, prospective, open-label study in which osteoporotic postmenopausal women self-administer synthetic hPTH-(1-34), alendronate, or both, every day for 2.5 years. Participants initially come to Massachusetts General Hospital once a month, and subsequently once every 3-6 months, for measurements of serum and urine indices of bone formation and resorption, serum and urine toxicity tests, and DXA/QCT measurements of bone mass. One-third of the participants take hPTH-(1-34) daily, one-third take alendronate once daily, and one-third take both daily (Phase A, months 0-30). Participants who complete Phase A are eligible for a 12 month extension study (Phase B, months 30-42), during which any alendronate treatment is continued without change and any hPTH 1-34 treatment is stopped. Participants who complete Phase B are eligible for a second 12 month extension study (Phase C, months 42-54), during which any alendronate treatment is continued without change and every participant takes hPTH 1-34. During Phases B and C, these participants come to Massachusetts General Hospital once every 6 months for measurements of serum and urine indices of bone formation and resorption, serum and urine toxicity tests, and DXA/QCT measurements of bone mass.