Why Is the Overuse Happening?
One reason for the inappropriate use of bone-modifying drugs could be confusion surrounding the recommendations because the drugs are recommended for some patients with prostate cancer.
Michael R. Laurent, MD, PhD, of Imelda Hospital, Bonheiden, Belgium, explained that the use of bone-modifying drugs is, paradoxically, often overlooked in settings where they are recommended — when patients have an elevated risk for osteoporosis or fracture.
“Guidelines are quite unequivocal in their recommendations to prevent osteoporosis in mostly older men who receive androgen deprivation therapy,” but “I think there is significant undertreatment” in these patients, Dr. Laurent told this news organization.
However, the recommendation for patients at risk for osteoporosis or bone fracture calls for less intense regimens, which may include lower-dose denosumab, administered once every 6 months, zoledronic acid, given yearly, or another lower potency agent, such as oral alendronate weekly, explained Philip J. Saylor, MD, an attending physician at Massachusetts General Hospital and assistant professor at Harvard Medical School, Boston.
Meanwhile, “monthly high-intensity therapy to prevent skeletal events should be reserved specifically for bone metastatic castration-resistant prostate cancer for more than just cost reasons,” Dr. Saylor said.
When it comes to the higher dose, monthly therapy in castration-sensitive prostate cancer, “we have no evidence that it is beneficial,” he said, adding that “when the prostate cancer itself is well controlled by hormonal therapy, there just aren’t very many pathologic fractures or other bone complications.”
Alongside possible confusion over the recommendations, many physicians also likely don’t know how much denosumab costs.
“In our recent physician interview study, we did find that most physicians were very much unaware of the cost of this drug, or the cost difference between denosumab and zoledronic acid, so I do think that lack of cost awareness is a factor,” Dr. Mitchell said.
Part of the reason may be how Medicare covers these agents. Typically, Medicare would not cover non-recommended indications, but “in this case, Medicare coverage is broader and includes both the guideline-recommended and non-recommended uses,” Dr. Mitchell explained.
However, the authors also identified a more cynical reason for non-recommended prescribing — promotional payments from drug makers to physicians.
In another recent paper, Dr. Mitchell said he found about “30% of doctors treating prostate cancer had received payments from Amgen for Xgeva [denosumab] promotion during the last year.”
These payments appeared to influence non-recommended prescribing: Among patients whose doctor had not received payments, 31.4% received non-recommended denosumab, which increased to nearly 50% of patients among doctors who had received payments.
Dr. Mitchell suggested a few ways to help curb inappropriate prescribing.
Medicare could, for instance, change its coverage policy to include only the recommended uses of these agents, Dr. Mitchell said.
More physician education would be another solution. “I think that physician education would be one ‘bottom-up’ approach that could work,” Dr. Mitchell added.
Dr. Mitchell, Dr. Takvorian, and Dr. Saylor had no disclosures to report. Dr. Laurent has received lecture and consultancy fees from Alexion, AM Pharma, Amgen, Galapagos, Kyowa Kirin, Menarini, Orifarm, Pharmanovia, Takeda, UCB, and Will Pharma.
A version of this article appeared on Medscape.com.