Filgrastim biosimilars show ‘substantial uptake’ among Medicare beneficiaries

The use of biosimilar biologics filgrastim-sndz and tbo-filgrastim increased substantially among Medicare beneficiaries between 2014 and 2016, according to a research letter published in JAMA.

The originator filgrastim product Neupogen (Amgen) and fingrastim-sndz (Zarxio, Novartis) share multiple indications for neutropenia and malignancy, whereas tbo-filgrastim (Granix, Teva) is a stand-alone alternative biologic with a single indication for reduction in the duration of severe neutropenia among patients with nonmyeloid malignancies receiving myelosuppressive anticancer drugs associated with febrile neutropenia.

“Biologic pharmaceuticals are complex, high-cost therapeutics used to treat severe and chronic conditions,” Steven Kozlowski, MD, director of the Office of Biotechnology Products at the FDA’s Center for Drug Evaluation and Research, and colleagues wrote. “Biosimilar biological products can increase access to therapy and lower health care costs.”

The Biologics Price Competition and Innovation Act of 2010 made possible the development of the biosimilar biologics. As of June 1, 2018, 10 biosimilars had received FDA approval.

Researchers used Medicare Part B claims to identify all filgrastim administrations of any dose between Jan. 1, 2014, and Dec. 31, 2016

The population included beneficiaries enrolled in Medicare fee for service from at least 6 months before to at least 10 days after administration.

Researchers classified patients as filgrastim originator recipients (n = 86,040; mean age, 71 years, 84% white; 54% women), tbo-filgrastim recipients (n = 19,083; mean age, 70.6 years; 84% white; 55% women) and filgrastim-sndz recipients (n = 9,955; mean age, 72 years; 86% white; 56% women).

Researchers noted beneficiaries who received filgrastim-sndz were on average slightly older. Overall, monthly administrations of any filgrastim product decreased 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% of all use, whereas use of the originator filgrastim product declined from 97% to 52%.

“Initial uptake of filgrastim-sndz was rapid, with monthly use surpassing tbo-filgrastim in March 2016,” the researchers wrote.

Twenty-two percent of beneficiaries who received filgrastim-sndz had previously used the originator filgrastim, whereas 73% were new users.

Although tbo-filgrastim has a single indication, the prevalence of indications was similar across all products. Tbo-filgrastim’s indication — for patients with nonmyeloid malignancies receiving myelosuppressive chemotherapy — was associated with 70% to 73% of claims across all products.

“The use of tbo-filgrastim beyond its labeled indication may result from clinicians’ familiarity with product use outside of the U.S. approval system, accepted practices, productive availability or other factors,” the researchers wrote.

Overall, researchers noted “substantial uptake of alternative filgrastim products occurred in 2014-2016, including among beneficiaries previously receipting the originator product.

“The more rapid uptake of filgrastim-sndz over the stand-alone biologic does not appear to be driven by the products’ list prices, as the tbo-filgrastim discount from the originator product was similar to or higher than the initial discount of 15% for filgrastim-sndz,” they added. – by Trudi Gilfillian

Disclosures: The authors report no relevant financial disclosures.