Presentation (CTI)

OBJECTIVES: Adalimumab (ADA) was approved in the US on 2002-12-31. Biosimilar adalimumab (bADA) was first approved in the US during 2023-01, and there were 10 approved formulations as of 2025-12. The objective of this study is to describe the treatment cost among patients initiating bADA/ADA in the US insured population.
METHODS: A retrospective analysis of HealthVerity’s taXonomy closed claims dataset included patients initiating bADA/ADA between 2024-01-01 and 2026-02-28 with continuous pharmacy and medical enrollment 12-months pre-index and 6-months post-index. Patients with a prescription/administration for another biologic within 12-months pre-index and/or >1 payer type were excluded. Prior biologic exposure was evaluated using a variable baseline. Treatment cost was calculated for the 6-month follow-up period. Successful treatment initiation was defined as proportion of days covered (PDC) >=80% at 6 months.
RESULTS: 1,971 bADA and 36,447 ADA patients were included. bADA share of the combined bADA/ADA market grew from 0.7% in 2024-01 to 25.2% in 2026-02. Patient characteristics were mean age 46.0 bADA vs. 45.7 ADA; female 66.8% bADA vs. 67.0% ADA; prior biologic experience was 2.7% bADA vs. 6.0% ADA. Mean 6-month treatment cost per initiator was $8,077 bADA ($8,319 Commercial, $8,567 Medicare Advantage, $7,164 Managed Medicaid) vs. $39,331 ADA ($37,032 Commercial, $37,903 Medicare Advantage, $44,118 Managed Medicaid). Mean 6-month PDC was 78.9% bADA vs. 77.8% ADA. Mean treatment cost per successful initiator was $10,321 bADA vs. $49,760 ADA.
CONCLUSIONS: Despite similar patient characteristics, rates of successful treatment initiation and lower treatment cost for bADA compared to ADA, bADA adoption accounts for only 25% of initiations two years post-approval. Further research into indication-level adoption, payer and prescriber dynamics, and the role of newer post-exclusivity treatments is needed.