Parathyroid hormone (1-84) and treatment of osteoporosis.

OBJECTIVE

To present the chemistry, pharmacology, and pharmacokinetics of parathyroid hormone (PTH) (1-84) and review the available clinical trials that evaluate its efficacy and safety; clinical applicability of this agent and its relationship to other Food and Drug Administration (FDA)-approved medications for treatment of osteoporosis are also discussed.

DATA SOURCES

A MEDLINE search (1996-December 2004) was completed, along with a review of information obtained from the manufacturer, NPS Pharmaceuticals. Key search terms included parathyroid hormone, PTH (1-84), and ALX 111.

STUDY SELECTION AND DATA EXTRACTION

Studies were selected based on their relevance and availability. Pertinent information, including objectives, design, demographics, outcomes, adverse events, dosing strategies, and therapeutic controversies, was extracted.

DATA SYNTHESIS

PTH (1-84) is being developed for treatment of osteoporosis. Recent studies have shown that, when administered intermittently as a subcutaneous injection, PTH (1-84) produces an increase in bone mineral density and prevents vertebral fractures. The fact that this agent contains the C-terminal region of PTH may differentiate it from PTH (1-34), teriparatide, which is approved by the FDA for treatment of osteoporosis. Further trials are necessary to determine the role of PTH (1-84) in combination with other treatments for osteoporosis and/or the order in which PTH (1-84) is given with these other agents. There are currently no comparative trials with other osteoporosis treatment modalities.

CONCLUSIONS

PTH (1-84), when given intermittently as a subcutaneous injection, appears to be a safe and efficacious treatment option for osteoporosis. Further trials are needed to determine its specific place in therapy compared with other treatment options.