OBJECTIVES: Ustekinumab, an anti-IL12/23 antibody, is used in the treatment of various autoimmune diseases. Recently, ustekinumab biosimilars have been approved for Crohn’s disease (CD), psoriasis (PsO), and psoriatic arthritis (PsA). The expected launch of ustekinumab biosimilars could reduce the associated cost burden for healthcare providers. Therefore, this study aimed to assess the cost-saving potential from the introduction of ustekinumab biosimilars from a payer perspective in the UK, Sweden, and Germany for adult patients currently treated with reference ustekinumab having CD, PsO, and PsA.

METHODS: For each country, Microsoft Excel-based budget impact model was developed to compare the healthcare costs between two scenarios: ‘world without’ versus ‘world with ustekinumab biosimilar’ over a three-year time horizon. For each scenario, population was taken from the UN database; further, prevalence and incidence rates for moderate-to-severe CD, moderate-to-severe PsO, and active PsA were derived from secondary literature. The annual share uptake of ustekinumab biosimilars was based on the case history of adalimumab biosimilars. Further, for each indication, patient-level annual treatment dose was calculated separately for the new and maintenance pools using the EMA-approved label. Treatment costs of reference ustekinumab and biosimilars were based on list price (June 2024) and analogue-based discounted prices, respectively.

RESULTS: This analysis estimated total savings of €440.0 million (M) in Germany, €49.5M (~£41.7M) in the UK, and €36.8M (~Kr414.6M) in Sweden over 3 years. Further, analysis estimated €5,167, €709 (~£597), and €3,388 (~Kr38,137) patient-level annual savings in the respective countries.

CONCLUSIONS: The introduction of ustekinumab biosimilars provides a significant opportunity for payers to reduce budgetary pressures and improve treatment accessibility across the UK, Germany, and Sweden. It should be noted that this analysis did not cover patients with moderate-to-severe ulcerative colitis, as the indication is still under patent protection for the reference medicine.