OBJECTIVES: To assess the average cost-effectiveness ratio (ACER) and the incremental cost-effectiveness ratio (ICER) of an adalimumab biosimilar for the treatment of psoriasis across the EU-5 countries (Italy, France, Spain, Germany, UK) compared to anti-interleukin therapy.

METHODS: A cost effectiveness (CE) model built in Excel was used to determine the ACER and the ICER of an adalimumab biosimilar vs anti-interleukin (IL) therapies. List prices of the reference biologic, as of February 2020, were used as input for the acquisition costs. Costs of adalimumab biosimilars were calculated by assuming approximate discount level of 70% from the reference biologic to reflect current and future market conditions. Efficacy scores (PASI 75, 90 and 100) were retrieved from a Bayesian network meta-analysis. CE ratios were calculated for a 16 week and 1-year period.

RESULTS: In Italy, for adalimumab biosimilars the average treatment cost per PASI 90-responder (ACER) was €9.570 (95% CrI*: €5.895 – €14.200) for 1 year of treatment. For secukinumab and risankizumab the average treatment costs per PASI 90-responder were €23.890 (95% CrI: €13.990 – €33.656) and €34.630 (95% CrI: €20.692 – €48.478) for 1 year of treatment, respectively. The ICERs for secukinumab and risankizumab compared to adalimumab biosimilars were calculated to be €50.240 (95% CrI: €20.277 – €96.216) and €69.498 (95% CrI: €34.172 – €113.546) per PASI 90 responder (1 year), respectively. These analyses were also conducted for the remaining EU-5 countries and other comparators. The results were generally robust to reasonable changes in input parameters.

CONCLUSIONS: The entry of biosimilars to the market may change the most cost-effective treatment landscape due to changes in ACER’s and ICER’s. The ICERs indicate that use of adalimumab biosimilars result in lower incremental treatment costs per PASI responder compared to anti-IL’s. Adalimumab biosimilars offer additional cost-effective opportunities to treat more psoriasis patients.

*CrI = Credible Interval