Bone health

Zoledronate results support bisphosphonate use in osteopenia

‘Practice changing’ results presented at the American Society for Bone and Mineral Research (ASBMR) in Montreal confirm the value of extending bisphosphonate treatment to postmenopausal women with osteopenia.

The findings, published concurrently in the New England Journal of Medicine, will influence future clinical guidelines and challenge PBS rules regarding the drug’s reimbursement, according to endocrinologist Professor Ian Reid of the University of Auckland.

“This is really going to wake up the PBS because Australia is very restrictive – you need to have had fractures. It’s very difficult for people who haven’t already had fractures to get access to these kind of treatments,” he told the limbic.

The New Zealand study randomised 2,000 women over 65 years with a T score between -1.0 and -2.5 to four infusions of zolendronate (5mg) or placebo at 18-month intervals.

Participants not already taking vitamin D received cholecalciferol before and during the trial while calcium was recommended but not supplied to participants.

After six years, 227 fragility fractures occurred in 190 women in the zolendronate group compared to 131 fractures in 122 women in the control group.

The number of women needed to be treated to prevent a single fragility fracture was 10.

Secondary outcomes including symptomatic fractures, vertebral fractures and height loss were all significantly reduced in the treated group of women compared to controls.

Marked differences in bone mineral density between the two groups were also seen by year three of the study.

Professor Reid said the reduction in risk of nonvertebral fractures seen with zolendronate was similar to that reported previously in patients with osteoporosis.

“I think for the first time we’re beginning to glimpse a way we might be able to really put some sort of cap on the number of fractures that are occurring in our increasingly elderly population.”

“It means that we can stop focusing on the 20% of people having fractures and focus on the much, much larger number of people at intermediate risk but who, because of the number of them, wind up accounting for the majority of the fractures.”

He said the bonus was that the drug was becoming a generic in most countries and was therefore an inexpensive intervention.

“Basically you need to treat ten people to prevent one fracture so you are spending a few hundred dollars to prevent a fracture whereas the sort of fracture we are talking about often have costs running into the tens of thousands of dollars.”

“And in many cases they lead to loss of independence. 40% of people who have a hip fracture never get back to their previous level of independence and 20% of them die. These are life-ending or life-altering injuries and they can be prevented.”

An editorial in NEJM reiterated that the vast majority of fractures occur in women with osteopenia not osteoporosis.

It added that there would be few adherence issues treating osteopenic women as per the study’s protocol given the infrequent administration of zolendronate.

“But just as importantly, this trial reminds us that risk assessment and treatment decisions go well beyond bone mineral density and should focus particularly on age and a history of previous fractures,” it said.

Professor Reid said the study also found a 30% decrease in mortality, cancers and heart attacks in the treated group – of borderline significance but consistent with some other data in closely related drugs.

“There has always been the suggestion that this class of drugs might be good for the heart and might be good for preventing cancer and this is the strongest evidence that we have had that you can use them in the general older population and see those benefits.

“People are planning and launching trials that will address those specific issues.”

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