Uptake of filgrastim biosimilars spikes among Medicare beneficiaries
There was a substantial uptake in the use of alternative filgrastim products, including its biosimilar filgrastim-sndz and the standalone alternative tbo-filgrastim, from 2014 to 2016 among Medicare Part B beneficiaries, including those who initially received the originator drug, according to findings published in JAMA.
“Biological products play a critical role in the treatment of many serious illnesses and they are often the only effective or available treatment option, but they can be very expensive,” Steven Kozlowski, MD, of the FDA Center for Drug Evaluation and Research, and colleagues told Healio Rheumatology. “Biosimilar products have the potential to reduce costs and increase access to these important treatment options.”
To analyze the uptake of filgrastim-sndz (Zarxio, Sandoz), the first biosimilar ever approved by the FDA, as well as the standalone alternative tbo-filgrastim (Granix, Sicor Biotech), compared with its originator drug, Neupogen (Amgen), Kozlowski and colleagues studied Medicare Part B claims data from all filgrastim administrations of any dose between Jan. 1, 2014, and Dec. 31, 2016. The researchers identified three cohorts, depending on whether the beneficiaries received Neupogen, filgrastim-sndz or tbo-filgrastim. Beneficiaries were included in multiple cohorts if they were treated with more than one filgrastim product during the study period.
To reviewing beneficiary demographics and the prevalence of indicated conditions, the researchers used least squares regression to characterize usage trends. In addition, they used a standardized mean difference threshold of 0.1 to note larger differences between the groups of beneficiaries.
According to the researchers, monthly administrations of filgrastim-sndz increased to 32% of all filgrastim use among Medicare Part B beneficiaries during the study period, with tbo-filgrastim increasing to 16%. During this time the originator drug declined in use from 97% to 52% of all filgrastim use. This resulted in a 13% decrease in monthly administrations of any filgrastim drug, from 28,520 at the start of 2014 to 24,898 by the end of 2016.
Filgrastim-sndz’s initial uptake was rapid, with monthly use surpassing that of tbo-filgrastim in March 2016, the researchers wrote. Among beneficiaries treated with filgrastim-sndz, 22% had initially received the originator drug, while 73% were first-time users. The prevalence of indications was similar across all three groups, despite tbo-filgrastim’s single indication for patients with non-myeloid malignancies treated with myelosuppressive chemotherapy. This indication was associated with 70% to 73% of claims across all three drugs, the researchers wrote.
“The U.S. market for biosimilars is still maturing, but biosimilars have the potential to offer significant savings after market entry, especially after two or more biosimilars are approved and on the market,” Kozlowski and colleagues said. “This evaluation found that the initial uptake of filgrastim-sndz was rapid, with monthly use surpassing tbo-filgrastim in March 2016. The data on filgrastim products utilization can inform future research and policy as the number of approved biosimilar products increases.” – by Jason Laday
Disclosure: Kozlowski reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.