SALT LAKE CITY—How are clinical outcomes and drug/administration costs of treatment affected when VA patients with rheumatoid arthritis (RA) use tumor necrosis factor inhibitor (TNFi) agents?

An analysis published recently in the journal Advances in Therapy compared veterans initiating and continuing a single TNFi with patients who subsequently switched to a different TNFi.1

The study, led by researchers from the VA Salt Lake City Healthcare System and the University of Utah School of Medicine, focused on patients enrolled in the VA Rheumatoid Arthritis (VARA) registry who initiated treatment with adalimumab, etanercept, or infliximab from 2003 to 2010. Outcomes analyzed were duration of therapy, Disease Activity Score based on 28 joints (DAS28) and direct drug and drug administration costs.

Results indicate that, of 563 eligible patients, 262 initiated a single TNFi therapy, 142 restarted their initial TNFi after a 90-day or longer gap in treatment (interrupted therapy), and 159 switched to a different TNFi.

Patients who switched had higher mean DAS28 before starting TNFi therapy than patients with single or interrupted therapy: 5.3 vs. 4.5 or 4.6, respectively. Mean duration of the first course was 34.3 months for single therapy, 18.3 months for interrupted therapy and 17.7 months for switched therapy. Mean post-treatment DAS28 was highest for patients who switched TNFi.

Average annualized costs for the first course, meanwhile, were $13,800 for single therapy, $13,200 for interrupted therapy and $14,200 for switched therapy. Mean annualized costs for the second course were $12,800 for interrupted therapy and $15,100 for switched therapy.

“Patients who switched TNFi had higher pre-treatment DAS28 and higher overall costs than patients who received the same TNFi as either single or interrupted therapy,” the study authors concluded.

1 Cannon GW, DuVall SL, Haroldsen CL, Caplan L, et. al. Clinical Outcomes and Biologic Costs of Switching Between Tumor Necrosis Factor Inhibitors in US Veterans with Rheumatoid Arthritis. Adv Ther. 2016 Aug;33(8):1347-59. doi: 10.1007/s12325-016-0371-0. Epub 2016 Jun 28. PubMed PMID: 27352377.