Woman Suffers Multiple Vertebral Fractures After Stopping Prolia: Case Report

The findings support previous studies which have linked Prolia discontinuation to an increased risk in bone fractures, though this is one of the first cases detected in a bone cancer patient.

Medical researchers continue to warn about the potential side effects of Prolia, a postmenopausal osteoporosis drug, which has been found to increase the risk of vertebral fractures that may occur after use of the medication has stopped.

Belgium researchers published a case study this month in the medical journal Bone Reports, which highlights problems experienced by a woman who suffered a vertebral fracture after she stopped taking Prolia. The findings adds to a growing body of evidence linking the side effects of Prolia to fractures after discontinuing use of the drug.

Prolia (denosumab, or DMAB) was introduced by Amgen in 2010, and was the first drug approved by the FDA for the treatment of postmenopausal osteoporosis.

Although Amgen issued warnings about the link between Prolia and bone fractures in Canada as early as 2012, concerns have been raised that insufficient warnings are still being provided in the United States.

This latest case report centers around a 43-year-old woman who went to an outpatient metabolic bone diseases clinic in February 2021, reporting severe lumbar back pain. The pain had been ongoing for three months.

According to the report, the woman was a cancer patient who had been taking Prolia for several years to treat other bone metastases, and had stopped using the drug in April 2020. By December 2020, her back pain had begun and were eventually linked to four new vertebral fractures through magnetic resonance imaging.

Researchers identified these as rebound-associated vertebral fractures (RAVFs), which have been linked in the past to discontinuation of Prolia. However, researchers noted it was rare to find such cases in cancer patients who had been treated with the drug.

“Cancer patients with bone metastases might not live long enough to allow consideration of denosumab discontinuation whereas osteoporosis patients might have a longer lifespan ahead,” the researchers explained. “Therefore, it is hard to tell if RAVFs are indeed more or less prevalent in cancer patients.”

The researchers said the case calls for clinicians to consider the risks and benefits of discontinuing Prolia in cancer patients with bone metastasis, and preventing and detecting RAVFs may be a crucial part of their care, since prompt treatment could be required.

“Future research regarding RAVFs should also include cancer patients with bone metastases, in order to provide supporting data to guide clinicians on the decision whether or not to discontinue denosumab in these patients,” the researchers concluded.

The case report supports findings of a study published by Israeli researchers in 2018, which found elderly women faced an increased risk of multiple vertebral fractures after Prolia discontinuation.

In 2013, the prominent consumer watchdog group Public Citizen raised concerns about the Prolia fracture risks, noting that the drug has been linked to reports of bone brakes following little or no trauma. The group indicated that Prolia appears to interfere with bone metabolism and the body’s immune system, resulting in breaks that may occur in situations that would not typically result in such an injury.

As more consumers learn that problems suffered in recent years may have been avoided with stronger warnings, it appears likely that Amgen may face Prolia bone fracture lawsuits.