my personal edition > osteoporosis > news


  E-Mail this DGDispatch to a colleague

DGDispatch

Adding Cyclic Parathyroid Hormone to Alendronate an Efficient and Economical Osteoporosis Treatment: Presented at ASBMR

By Mary Beth Nierengarten

MINNEAPOLIS, MN -- October 12, 2003 -- Adding parathyroid hormone (PTH) therapy to long-term use of alendronate for osteoporosis stimulates bone formation and increases bone mineral density (BMD).

Additionally, the use of cyclic PTH is comparable to the use of daily PTH in this regard, suggesting an efficient and economical treatment, researchers reported here September 22^nd at the American Society for Bone and Mineral Research 25^th Annual Meeting.

Lead investigator Felicia Cosman, MD, clinical director, The National Osteoporosis Foundation, and medical director, Clinical Research Center, Helen Hayes Hospital, West Haverstraw, New York, United States, described the rationale for evaluating the use of cyclic PTH in patients who continue to use alendronate.

Dr. Cosman said the idea came from previous clinical data that show only modest BMD changes in patients who receive PTH after stopping alendronate as well as biochemical data that indicate that bone formation is elevated more markedly during early therapy with PTH.

To evaluate whether repeated 3-month cycles of PTH therapy added to long-term use of alendronate could produce equal or increased bone response compared to daily PTH therapy, Dr. Cosman and colleagues conducted a 15-month trial of 126 patients with osteoporosis who were taking alendronate for at least 1 year (mean of 3.2 years).

For the study, patients continued to take alendronate 70 mg/week; 26 were randomised to receive daily PTH (1-34h PTH, 25 mcg by subcutaneous daily injection), 27 to cyclic PTH (25 mcg PTH daily for cycles of 3 months on and 3 months off), and 24 received alendronate alone.

Results at 9 months for the first 77 patients who completed therapy showed no significant changes in markers for bone turnover in the alendronate-alone group. For both PTH treatment groups, significant rapid increases in bone formation markers were noted during the first 3 months. For daily PTH, these increases continued throughout the 9 months and ranged from 80% to 300% for different markers. For cyclic PTH, the increases noted in the first 3 months declined during the next 3 months when PTH was not given, and then robustly rose again during the second PTH cycle, with 60% to 270% increases in bone turnover markers from baseline. The increases in bone turnover markers from baseline were significant for both the daily and cyclic PTH groups (P<0.001).

Increases in lumbar spine BMD showed a similar pattern, with progressive increases shown in the daily PTH group and initial increase in the cyclic PTH group followed by a slight decline to 6 months and then an increase to 9 months. No significant differences in BMD change were found at 9 months between the PTH groups, with a 4.3% spine BMD increase in the daily group compared to a 3.8% increase in the cyclic group, both of which were significant from baseline (P<0.0001). In patients treated with alendronate alone, a smaller increase of 2% in spine BMD was noted, which was still significant from baseline (P<0.04).

Dr. Cosman emphasised that this is a preliminary study designed to look only at one outcome, and does not offer data on fracture outcomes. She added that, "despite ongoing PTH therapy, I hypothesise that the bone turnover markers will go down over time."


[Study title: Daily versus Cyclic PTH Combined with Alendronate versus Alendronate Alone for Treatment of Osteoporosis. Abstract 1120]

E-Mail this DGDispatch to a colleague

To print, use this version