Source: DGNews  |  Posted 8 years ago

By Mary Beth Nierengarten

MINNEAPOLIS, MN -- September 24, 2003 -- Women who continue alendronate therapy for as long as three years maintain higher bone mineral density (BMD) compared to women who discontinue treatment, interim results of the Fracture Intervention Trial (FIT) show.

Kristine Ensrud, MD, lead investigator, Veterans Administration Medical Center and University of Minnesota, Minneapolis, Minnesota, reported the results in a poster session here September 19th at the 25th Annual Meeting of the American Society for Bone and Mineral Research.

According to Dr. Ensrud, "Even in those women who discontinued therapy after 5 years, the effects of alendronate persist as shown by the higher levels of BMD sustained in these women compared to their baseline levels."

To determine whether the increases in BMD and reduced fracture risk found in 1,099 women randomised to receive alendronate in FIT over a mean of 5 years would persist or even provide further gains for a longer period of time, Dr. Ensrud and colleagues re-randomised these women for an additional 5 years to alendronate at 10 mg/day (30%), alendronate at 5 mg/day (30%), or placebo (40%). The women also received calcium and vitamin D supplements.

This 3-year interim analysis showed that the mean BMD was maintained or increased in the women who had prior alendronate therapy and who then received either dose of alendronate compared to the placebo group. A 2.0% difference in BMD was found at the total hip and a 2.6% difference at the lumbar spine between the two groups.

Compared to placebo, women who continued to be treated with alendronate had a higher cumulative increase in total hip BMD from FIT baseline (0.9% vs. 3.0%, respectively).

Women treated continuously with alendronate showed relatively stable changes in bone turnover markers (i.e., urinary N-telopeptide/Cr and bone alkaline phosphatase) from FIT baseline. Women on placebo showed partial resolution of the prior treatment effect (i.e., 25% increasing urinary N-telopeptide/Cr and 17% increase in bone alkaline phosphatase). However, these women retained higher levels of BMD than they had at baseline.

"Because this was a planned interim analysis," said Dr. Ensrud, "we did not look at the fracture risk associated with discontinuation of therapy." She said the full 5 year study will address what happens to fracture risk when women discontinue therapy.

[Study title: The Fracture Intervention Trial Long Term Extension (FLEX): 3 Year Interim Results. Abstract F-348]