Biological tapering is cost-effective in patients with inflammatory arthritis in the biosimilar era: secondary...

We assessed the cost-effectiveness of disease activity-guided tapering to continuation of biologics as usual care in inflammatory arthritis.

Adults with rheumatoid arthritis, psoriatic arthritis, or axial spondyloarthritis on stable biological dose (including biosimilars) and in low disease activity ≥12 months were randomised (2:1) to disease activity-guided tapering or continuation of biologics as usual care.The cost-effectiveness evaluation assessed the 18-month quality-adjusted life years (QALYs), hospital costs, and patient costs. Analyses were based on intention-to-treat. Missing short form six-dimensional (SF-6D) values were imputed with the mean SF-6D value in the relevant group at the specific time point. Patients lost to follow-up were assumed to continue their baseline biological dose onwards. We used a 2-sample t tests with unequal variance to capture between-groups differences with 95% CI.

Of 142 included patients, 78% were treated with biosimilars. At 18 months, 75% (71/95) of the tapering group and 17% (8/47) of the control group were on a tapered biological dose. We found no difference between groups in QALYs, mean difference: 0.008 points (95% CI: -0.008 to 0.024). Patients in the tapering group incurred significantly lower mean hospital costs than the control group, between-group difference: -1936€ (95% CI: -3753€ to -119€). Mean patient costs were comparable between groups: -52€ (95% CI: -350€ to 246€).

Disease activity-guided tapering of biologics in a biosimilar era resulted in substantial reductions in 18-month hospital costs, whereas the impact on QALY and patient costs was similar. Thus, the tapering algorithm was cost-saving.