Full length parathyroid hormone (1-84) in the treatment of osteoporosis in postmenopausal women

Abstract

Objective: To review the pharmacological properties and the available clinical data of full length parathyroid hormone (PTH) in post-menopausal osteoporosis.

Sources: A MEDLINE search was completed, together with a review of information obtained from the manufacturer and from the medicine regulatory agencies. STUDY AND DATA SELECTION: Studies were selected according to relevance and availability. Relevant information (design, objectives, patients' characteristics, outcomes, adverse events, dosing, etc) was analyzed.

Results: Different studies have shown that, when administered intermittently as a subcutaneous injection in the abdomen, PTH increases bone mineral density (BMD) and prevents vertebral fractures. On completion of PTH therapy (up to 24 months), there is evidence that sequential treatment with alendronate is associated with a therapeutic benefit in terms of increase in BMD. Further trials are necessary to determine long-term safety and the role of PTH in combination with other treatments for osteoporosis and the effect of repeated cycles of PTH followed by an anti-catabolic agent. There are currently no completed comparative trials with other osteoporosis treatments.

Conclusions: Full length PTH, given intermittently as an abdominal subcutaneous injection, appears to be a safe and efficacious treatment option for high risk osteoporosis. More data are needed to determine its specific role in osteoporosis treatment.

Figure 1

New vertebral fractures in PTH and Pcb groups. TOP study. Abbreviations: Pcb, placebo; PTH, parathyroid hormone; TOP, treatment of osteoporosis with parathyroid hormone.

Figure 2

Number (left) and severity (right) of new fractures in PTH and Pcb groups. TOP study. Abbreviations: Pcb, placebo; PTH, parathyroid hormone; TOP, treatment of osteoporosis with parathyroid hormone.

Figure 3

Changes in lumbar spine BMD (%) during the TOP study and its extension (OLES). Abbreviations: BMD, bone mineral density; OLES, open-label extension study; TOP, treatment of osteoporosis with parathyroid hormone.

Figure 4

Changes in bone turnover markers (formation: N-propeptide of type I collagen [PINP], bone specific alkaline phosphatase [BALP]; resorption: serum C-terminal telopeptide of type I collagen [sCTX]) during one year of therapy with PTH. TOP study. Abbreviations: PTH, parathyroid hormone; TOP, treatment of osteoporosis with parathyroid hormone.