Annual acquisition and administration cost of biologic response modifiers per patient with rheumatoid arthritis, psoriasis, psoriatic arthritis, or ankylosing spondylitis.

OBJECTIVE: To estimate annual biologic response modifier (BRM) cost per treated patient with rheumatoid arthritis, psoriasis, psoriatic arthritis, and/or ankylosing spondylitis receiving etanercept, abatacept, adalimumab, certolizumab, golimumab, infliximab, rituximab, or ustekinumab.

METHODS: This was a cohort study of 69,349 commercially insured individuals in a nationwide claims database with one of these conditions that had a claim for one of these BRMs between January 2008 and December 2010 (the index BRM/index date). Cost per treated patient was calculated as the total BRM acquisition and administration cost to the payer in the first year after the index date (including costs of other BRMs after switching) divided by the number of patients who received the index BRM. Etanercept was selected as the reference for comparisons.

RESULTS: Etanercept was the most commonly used index BRM (n = 32,298; 47%), followed by adalimumab (n = 20,582; 30%), infliximab (n = 11,157; 16%), abatacept (n = 2633; 4%), rituximab (n = 1359; 2%), golimumab (n = 687; <1%), ustekinumab (n = 388; <1%), and certolizumab (n = 245; <1%). Using etanercept as the reference, the cost per treated patient in the first year across all four conditions was 102% for adalimumab and 108% for infliximab. Newer BRMs had costs relative to etanercept that were 90% to 102% for rheumatoid arthritis, 132% for psoriasis, 100% for psoriatic arthritis, and 94% for ankylosing spondylitis.

LIMITATIONS: Potential study limitations were the lack of clinical information (e.g., disease severity, treatment outcomes) or indirect costs, the inability to compare costs of newer BRMs across all four conditions, and much smaller sample sizes for newer BRMs.

CONCLUSIONS: Of the BRMs that are approved for indications within all four conditions studied, etanercept had the lowest cost per treated patient when assessed across all four conditions.