An analysis of data from 337 people with treatment-refractory ankylosing spondylitis (AS) indicated 88.1% received only one line of anti–tumor necrosis factor-α (anti-TNF-α) therapy while the remaining 11.9% switched to one or more anti-TNF-α agents. The results were presented at the 2015 annual meeting of the International Society for Pharmacoeconomics and Outcomes Research.
Value-Based Care in Rheumatology asked lead investigator Jacqueline Palmer, PharmD, whether she was surprised by any of the results.
“In a structurally progressive disease like AS, it is surprising to see a [relatively] high number of patients discontinue use of biologic treatments, which could have implications for the long term,” noted Palmer, associate director, Health Economic & Outcomes Research, Novartis Pharmaceuticals Corporation, East Hanover, New Jersey. “In addition, patients [who had only] one line (first) of biologic treatment had the highest medical costs. Further study is needed, but this could be due to severity of symptoms at the onset of treatment.”
Palmer’s team used data gathered between January 1, 2005, and September 30, 2013, from Truven Health’s MarketScan Commercial Claims and Encounters Database and the Medicare Supplemental and Coordination of Benefits Database.
Two hundred and ninety-seven patients did not switch from one anti-TNF-α therapy to another. Among those patients, 217 (73.1%) discontinued the biologic during a 3-year follow-up and 80 (26.9%) remained on the original biologic. Another 30 of the 337 patients (8.9%) received a second biologic and 10 (3%) also received a third.
Overall, the most commonly used biologics were etanercept (41.5% of patients), adalimumab (40.9%), infliximab (12.2%), and golimumab (5.3%). Etanercept was also the most commonly used first-line biologic among patients who switched to another agent (62.5% of 40) while adalimumab was the most popular biologic among patients who were not switchers (43.4% of 297).
Medical costs totaled $354 for nonswitchers. The respective totals were $225 for people who received 2 lines of anti-TNF-α medications and $112 for those who received 3 or more lines. Total pharmacy drug costs were similar in all 3 groups, non-switchers at $1899, 2 lines $1955, and 3 lines $1890.
Palmer J, Liao M, Herrera V, et al. Modification of biologic therapy in patients with ankylosing spondylitis. In: Proceedings from the ISPOR 20th International Annual Meeting; May 16-20, 2015; Philadelphia, PA. Abstract PMS19.