Background/Purpose: RA patients (pts) receiving anti-TNF therapy may have an inadequate response (IR) to 1st-line treatment. Among pts for whom treatment fails, little is known about associated treatment costs or the proportion with an IR to a 2nd-line anti-TNF. We quantified the RA-related healthcare cost of treating pts with an IR to an anti-TNF using an adaptation of a published administrative claims-based algorithm to identify IR. We examined the probability of IR to 1st- and 2nd-line anti-TNF biologics, and assessed RA-related healthcare costs among pts with an IR to 1st- or 2nd-line treatments.

Methods: This was a retrospective, observational cohort study based on administrative claims data. Adults (aged ≥18 yrs) with RA initiating an anti-TNF between 1-1-2009 and 12-31-2013 were included. Pts were required to have continuous insurance enrollment for 12 mths before initiating an anti-TNF, and no treatment with any biologics during this period. Pts who experienced an IR to 1st-line anti-TNF and were treated with a 2nd-line anti-TNF were analyzed as a sub-sample. Variable-length follow-up was measured for both the 1st- and 2nd-line treatments, beginning with initiation of an anti-TNF and continuing until one of the following: use of a biologic other than the initiated anti-TNF, disenrollment from health insurance or reaching the study end date of 12-31-2013. IR was defined as a composite of discontinuation or switch of the initiated anti-TNF, anti-TNF dose escalation, initiation of a new non-biologic DMARD, new/increased oral glucocorticoid (OGC) use/dose or receiving ≥2 injections of glucocorticoid (IGC). Kaplan–Meier analysis was used to calculate probability of IR over time. RA-related healthcare utilization and costs were expressed in per-pt per-month (PPPM) units and corresponded to medical claims with an International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code for RA, the initiated anti-TNF and non-biologic DMARDs.

Results: A total of 26,785 pts met our inclusion criteria for the 1st-line analysis; 4638 for the 2nd-line analysis. Mean follow-up time was 525 days for 1st line and 383 days for 2nd line; Kaplan–Meier-estimated probabilities of IR were 67% at 6 mths, 82% at 12 mths and 91% at 24 mths for 1st line; 77%, 89% and 95% at 6, 12 and 24 mths for 2nd line. In both lines, the primary reason for IR was discontinuation of initiated anti-TNF (52–61% of pts), followed by: 2+ IGC (30–33%); switch of initiated anti-TNF (23–34%); initiation of a new non-biologic DMARD (14–27%); anti-TNF dose escalation (15–19%); new/increased OGC use/dose (13–15%). Average RA-related PPPM costs were $3883 (SD $10,697) for pts with an IR to 1st-line therapy and $6831 (SD $32,849) for pts with an IR to 2nd-line therapy.

Conclusion: In this retrospective study using real-world data, a high proportion of pts with RA experienced an event indicative of IR to 1st- or 2nd-line anti-TNF treatment. The RA-related healthcare costs of treating pts with IR were substantial.¹

1.    Original abstract © EULAR/BMJ. First presented at EULAR 2016 and published in Ann Rheum Dis 2015;74 (Suppl 2):1032. Any reprints, promotional options, education material etc have to be done through the original source (ARD/BMJ).