Biosimilar Uptake Patters of Filgrastim Among Medicare Beneficiaries

A number of biosimilar agents have been approved by the U.S. Food and Drug Administration. A study published in JAMA evaluated the uptake of filgrastim-sndz—the first U.S. biosimilar approval—and its reference filgrastim product, which are approved to treat neutropenia and malignancy.

Researchers identified all Medicare Part B claims for filgrastim between January 1, 2014, and December 31, 2016, using the Healthcare common Procedure Coding System billing codes. They included claims for beneficiaries who were enrolled in Medicare fee-for-service from at least 6 months before to at least 10 days after administration. They evaluated beneficiary demographics and prevalence of indicated conditions. During that time, 86,040 eligible beneficiaries received reference filgrastim, 19,083 received tbo-filgrastim, and 9,955 received filgrastim-sndz.

Monthly administrations of any filgrastim product decreased by 13%—from 28,520 in January 2014 to 24,898 in December 2016. Monthly administrations of filgrastim-sndz increased to 32% of all filgrastim use and tbo-filgrastim increased to 16%, while the reference filgrastim product declined from 97% to 52%. Initial uptake of filgrastim-sndz was rapid, with monthly use surpassing tbo-filgrastim in March 2016.

Beneficiaries who received filgrastim-sndz were slightly older in age (mean age = 72.0 years compared with 70.6 years with tbo-filgrastim and 71.0 years with reference filgrastim). Product choice also differed by geographic region and Medicare enrollment status. For example, among patients in the south, 44% (n=4,409) received filgrastim-sndz compared with 42% (n=35,763) of those receiving reference filgrastim and 32% (n=6,036) of those receiving tbo-filgrastim. In addition, 80% of patients (n=7,984) receiving filgrastim-sndz have a Medicare status of aged (without end-stage renal disease) compared with 77% (n=66,602) of those receiving reference filgrastim and 74% (n=14,129) of those receiving tbo-filgrastim.

Among beneficiaries who received filgrastim-sndz, 22% had previously received the reference filgrastim, while 73% were new users.

“Substantial uptake of alternative filgrastim products occurred in 2014-2016,” according to the authors. However, they noted that the more rapid uptake of filgrastim-sndz did not appear to be related to the products’ list prices, as the tbo-filgrastim discount was similar to or higher than the initial discount of 15% for filgrastim-sndz.

“Data on filgrastim utilization can inform future research and policy as the number of approved biosimilar products increases,” the researchers concluded.