This article is more than 5 years old. Information may no longer be current.
Risk for fracture reduced by single infusion of zoledronic acid
Click Here to Manage Email Alerts
The risk for fracture appeared to decrease for more than 1 year after a single infusion of zoledronic acid, according to data from a post hoc analysis of two studies.
Researchers collected data from 1,367 patients who were included in the Health Outcomes and Reduced Incidence with Zoledronic Acid Once Yearly-Pivotal Fracture Trial (HORIZON-PFT) and HORIZON-Recurrent Fracture Trial (RFT) studies. Both studies were double blind, placebo-controlled, multicenter, randomized trials.
According to data, there was a 32% reduction in clinical fracture in patients who received only a single infusion of zoledronic acid 5 mg compared with those who were administered placebo during a 3-year follow-up period (95% CI, 2-53). These data were comparable with the 34% reduction in fracture observed in patients who received three or more annual infusions, (95% CI, 23-43). Moreover, new morphometric vertebral fractures decreased by 68% among patients in the single-infusion group (P=.004), researchers wrote. Between-group differences in bone mineral density were 3.8% (95% CI, 2.1-5.4) for the single-infusion group and 6.2% (95% CI, 5.9-6.4) for patients receiving three infusions at 3 years.
“This post hoc analysis of data combined from two clinical trials suggest that there is a statistically and clinically significant reduction in clinical fracture risk over 3 years after a single infusion of zoledronic acid,” the researchers wrote. “This is not a definitive finding because it is a post hoc analysis of a subgroup that has been identified based on a postrandomization characteristic.”
The researchers said patients from each group who only had a single infusion are comparable at baseline for predictive factors of risk for fracture, including age, weight, history of previous fractures and sex. They suggest prospective fracture endpoint studies of zoledronic acid.
Disclosure: Some of the researchers report various financial ties to Amgen, Merck, Novartis and Roche.
Perspective
Back to Top
Nelson B. Watts, MD
This is an intriguing study. Most therapies are somewhat arbitrary and “evidence-based” medicine is limited to the evidence at hand. Years ago, I was involved in a trial of cyclic etidronate, which we gave daily for 2 weeks, with the cycle repeated every 3 months. Several people thought they would be creative — what about 2 weeks of treatment every 2 months or 3 weeks every 3 months or 1 week every month?
The answer was that we only knew the outcome of the one regimen we investigated. It is certainly possible that one dose of zoledronic acid provides fracture protection over 3 years. That’s good, but is it as good as repeating the dose yearly, as is currently done? Given the large sample size needed to do comparative studies, it is unlikely that the “evidence” will ever be available. While a reasonable goal is to use the smallest amount of medication for the shortest time necessary, I’m reluctant to abandon the “evidence” from established trials at this time.
Click Here to Manage Email Alerts