Which Therapy is Most Cost-Effective for Curbing Skeletal Risks in Breast Cancer?

10/25/17

By Marilynn Larkin

NEW YORK (Reuters Health) – In women with breast cancer, zoledronic acid taken every three months is more cost-effective for reducing the risk of skeletal-related events than monthly zoledronic acid or monthly denosumab, researchers say.

“The new 2017 ASCO guidelines for the use of bone-modifying therapy in individuals with bone metastases recently endorsed every three-month zoledronic acid because of high-level evidence from three randomized trials, including ours (http://bit.ly/2hK5Mrq), showing that (this regimen) was non-inferior to the standard of monthly zoledronic acid,” Dr. Charles Shapiro of Icahn School of Medicine at Mount Sinai in New York City told Reuters Health.

Zoledronic acid became generic in 2013, whereas monthly denosumab is on patent until 2022-25, he added.

Dr. Shapiro called his group’s new research “one of the only cost-effectiveness studies not sponsored by the companies that make zoledronic acid (Novartis) and denosumab (Amgen).” Those studies showed favorable results for the sponsoring company’s product.

As reported in the Journal of Clinical Oncology, online October 12, the mean costs of monthly denosumab are nine-fold higher than generic zoledronic acid every three months.

Quality-adjusted life-years were nearly identical among the three treatments: zoledronic acid every three months, monthly zoledronic acid, and monthly denosumab. Therefore, the authors concluded, zoledronic acid every three months is the most cost-effective therapy.

Dr. Shapiro said, “the total costs per treatment strategy (which includes costs of drug, administration, and costs of skeletal-related events) are $5,667 and $57,200/year for generic every three months zoledronic acid and monthly denosumab, respectively.” For monthly zoledronic acid, the annual cost is $9,290.

Sensitivity analyses showed that compared with monthly zoledronic acid, the mean incremental costs per mean skeletal-related event avoided for monthly denosumab ranged from $137,905 to $283,109.

“Where we assumed that the probability of skeletal-related events on denosumab were reduced by 50%, 75%, and 90% relative to zoledronic acid every three months, the costs of monthly denosumab per mean skeletal-related event avoided ranged between $162,918 and $347,655,” Dr. Shapiro said.

The study had limitations in that “the model chosen (Markov) and the assumptions made can influence the results,” he continued. “Also, the study only considered a two-year time period.”

Further, neither this study nor previous ones considered patient preferences, he observed. Some patients may prefer subcutaneous injections (denosumab) to intravenous administration (zoledronic acid).

“As we move toward a value-based health care model - simply stated as the benefit to patient/over the costs of treatment - every three-month zoledronic acid is a more cost-effective and viable option to monthly denosumab,” he said.

“Everyone acknowledges that healthcare costs are going up, but in the U.S., where any physician can essentially prescribe any drug without regard to what it costs, these kind of cost-effectiveness analyses have little influence on physician choice of drug,” he acknowledged.

“This system is not sustainable - we can’t keep on ignoring the cost of drugs,” Dr. Shapiro concluded.

Dr. Tracey O’Connor, a medical oncologist at Roswell Park Cancer Institute in Buffalo, New York, told Reuters Health by email, “There is now good evidence to support the administration of zoledronic acid once every three months to prevent skeletal-related events in patients with metastatic breast cancer.”

“While monthly denosumab is 23% better when compared to monthly zoledronic acid at reducing the time to the first and subsequent skeletal-related event, the price differential is substantial,” said Dr. O’Connor, who was a coauthor of an earlier zoledronic acid study but did not participate in the current study.

“For patients for whom cost is a consideration, zoledronic acid dosed every three months represents a viable alternative to denosumab,” she concluded.

SOURCE: http://bit.ly/2zDoxkJ

J Clin Oncol 2017.

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