Despite recurrent dose escalation, the use of the biosimilar infliximab resulted in appreciable cost savings compared with reference golimumab in the treatment of rheumatoid arthritis, according to results from a study published in Arthritis Research & Therapy.
Researchers retrospectively studied 2 cohorts of patients with rheumatoid arthritis who were treated with either intravenous infliximab (n=5174) or golimumab (n=2843). Data were collected from the Centers for Medicare & Medicaid Services fee-for-service database from 2012 to 2016. The study compared time receiving treatment, dose escalation, and costs paid by Medicare between the agents from the start of therapy to 18 months. The primary outcomes measured were costs paid by Medicare from treatment initiation to 78 weeks and the frequency of dose escalation.
After analysis, the researchers found that dose escalation occurred more frequently for patients treated with infliximab compared with golimumab (50% vs 5%). In addition, for patients who were maintained on infliximab, the frequency of dose escalation was even higher (72%).
Despite more frequent dose escalation, the costs were greater for golimumab (adjusted least square mean dollar amount, $28,146) than for infliximab (adjusted least square mean dollar amount, $21,216).
“Only when patients escalated infliximab to ≥8 mg/kg every 6 weeks was golimumab [intravenous] at break-even or less expensive,” the researchers wrote.
One key limitation of the study was the absence of safety or tolerability data on each therapy.
“The costs associated with dose escalating infliximab to 10 mg/kg every 4 or 6 weeks are substantial and likely offset even appreciable dose savings associated with biosimilar,” they concluded.
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Curtis JR, Xie F, Kay J, Kallich JD. Will savings from biosimilars offset increased costs related to dose escalation? A comparison of infliximab and golimumab for rheumatoid arthritis. Arthritis Res Ther. 2019;21(1):285.