Understanding utilization patterns of biologics and biosimilars in the United States to support postmarketing studies of safety and effectiveness

Abstract

Purpose: To describe utilization of filgrastim and infliximab, the first two products with biosimilars approved in the United States. Methods: We identified use of filgrastim (reference, tbo-filgrastim, and filgrastimsndz) and infliximab (reference, infliximab-dyyb, and infliximab-abda) in the Sentinel Distributed Database using Healthcare Common Procedure Coding System (HCPCS) codes and National Drug Codes (NDCs) from January 2015 to August 2018. We calculated the proportion of use by code type and assessed uptake over time. We compared baseline patient characteristics and treatment indications. Among patients with >1 exposure episode, we characterized gaps between episodes. Results: Use was identified primarily via HCPCS codes (filgrastim: 86.4%-97.7%; infliximab: 87.8%-100%) although some was identified via NDCs (filgrastim: 2.2%-13.5%; infliximab: <0.1%-6.5%). Filgrastim reference product use declined from 89.4% in January 2015 to 30.3% in June 2018, with corresponding increases in filgrastim-sndz (0% to 49.3%) and tbo-filgrastim (10.6% to 20.4%). Infliximab biosimilar uptake was low (9.7% in June 2018). We identified 94 846 filgrastim reference product, 27 143 tbo-filgrastim, and 38 264 filgrastim-sndz users. For infliximab, we identified 125 412 reference product, 1034 infliximab-dyyb, 49 infliximab-abda, and 4855 undetermined biosimilar users. Patients receiving filgrastim products were largely similar, but differences in age, sex, and indication were observed across infliximab product users. The median exposure episode gap ranged from 1 to 3 days for filgrastim and 48 to 50 days for infliximab. Conclusion: Use of biosimilar filgrastim has increased in the United States, but infliximab biosimilar use remains low. Data on identification of biosimilars in claims data and observed gaps between exposure episodes can be used to support drug safety studies of biosimilars.

Uptake and cost of biosimilar filgrastim among Medicare and Medicaid populations in 2015-2018

“…17 A recent study using the FDA Sentinel Distributed Database found that filgrastim-sndz's use had increased to 49.3% by August 2018. 18 Similarly, Karaca-Mandic et al also confirmed similar uptake among the commercially insured and Medicare Advantage populations. 19 In addition, Socal et al used the 2015-2017 Medicare Part B claims data and found an improved uptake of biosimilar filgrastim in the Medicare Part B program.…”

“…Findings from the current study could fill the important knowledge gap in the uptake and spending of biosimilar filgrastim in national populations, especially Medicare feefor-service beneficiaries with Part D prescription coverage and Medicaid beneficiaries. Although the Dutcher et al study described the use of biosimilar filgrastim-sndz at the national level, using the FDA's Sentinel Distributed Database, 18 no findings in cost or spending of the product were reported.…”

Trends in Use of Granulocyte Colony-Stimulating Factor Following Introduction of Biosimilars Among Adults With Cancer and Commercial or Medicare Insurance From 2014 to 2019

“…Little is known about the impact and uptake of this device and approved biosimilars on G-CSF prescribing patterns and the uptake of these new products in the United States. Existing studies evaluated utilization at the prescription level rather than patient level, 16 , 17 , 18 , 19 , 20 , 21 limiting insights into trends within certain patient groups, for example, those with high FN risk owing to regimen or patient factors.…”

Increasing Biosimilar Utilization at a Pediatric Inflammatory Bowel Disease Center and Associated Cost Savings: Show Me the Money

“…In the United States, biosimilars have been underutilized 15 despite multiple position statements from societal organizations supporting their use in IBD management 12,13 and medical evidence supporting their safety and efficacy. [8][9][10][11] Biosimilars have seen a minimal increase in market share from 0.1% in 2017 to 0.9% in 2019.…”