Background: Tocilizumab is an interleukin-6 inhibitor (IL-6i) biologic approved to treat rheumatoid arthritis, giant cell arteritis, systemic and polyarticular juvenile idiopathic arthritis, cytokine release syndrome due to chimeric antigen receptors T-cell medicines, and COVID-19 ^[1] . Although tocilizumab has been shown to effectively treat and manage patient symptoms and significantly improve patient quality of life ^[2-4] , its use is limited in many countries due to the high price of the reference product ^[5-6] . Recently, a biosimilar tocilizumab was launched which may help reduce existing spending on tocilizumab and/or enable budget-neutral expanded patient access.

Objectives: To develop a model to evaluate the budget impact and expanded access associated with a novel tocilizumab biosimilar in the United Kingdom (UK).

Methods: A budget impact model was developed that compares the overall cost of IL-6i treatment in a world without a tocilizumab biosimilar to a work with. The model ran for a three-year time horizon and included three basic states, naïve, current, and leave. A patient could start in the naïve state which included incident-naïve (new to IL-6i) or switch-naïve (new to the specific IL-6i). Patients could either discontinue the IL-6i (ie, move to the leave state), move to another IL-6i (captured by the market shares per indication per year), or stay on the current treatment for the model’s time horizon (ie, move to the current state). The number of patients in each year was informed by prevalence and incidence data for each indication. The assumption for percent of IL-6i use was based on peer-reviewed data that discussed the extent of IL-6i use in a cohort of patients in the UK. Biosimilar tocilizumab was assumed to occupy 50%, 75%, and 100% of the market in year 1, year 2, and year 3, respectively. The same market share was assumed for each approved indication (COVID-19 was excluded due to its currently low incidence and prevalence). Biosimilar tocilizumab was assumed to have a 15% discount compared to the reference product tocilizumab. The expanded access due to a tocilizumab biosimilar was calculated by dividing the generated direct savings by the cost of the tocilizumab biosimilar, resulting in the number of additional patients that could be treated each year under budget neutrality.

Results: Based on the inputs for prevalence, incidence, and percent IL-6i users, the number of patients treated by tocilizumab in the UK was assumed to be 15,402. In year 1, assuming a 50% market share of a tocilizumab biosimilar, the budget savings were ₤14.9 million with 1,359 additional patients treated (8% increase in patient access). In year 2, assuming a 75% tocilizumab biosimilar market share, the budget savings were ₤23.1 million with an additional 2,111 patients treated (14% increase). In year 3, assuming exclusive use of a tocilizumab biosimilar, the budget savings were ₤32.3 million, with 2,950 additional patients treated (19% increase). The cumulative savings across the time horizon (3 years) was ₤70.4 million, with a total of 6,425 additional patients treated.

Conclusion: The use of a tocilizumab biosimilar was projected to result in substantial savings in the UK, while providing a similar efficacy and safety profile as the reference product. In turn, these savings could be reinvested into the healthcare system, allowing more patients to be treated with an effective biologic without increasing current expenditure.

REFERENCES: [1] EMA (2021) RoActemra Product Information.

[2] Townes (2012) Open access rheumatology: research and reviews 5, 87-92.

[3] Collins (2019) Nat Rev Rheumatol 15, 188.

[4] Brunner (2021) Arthritis Care Res 73 (9), 1264-1274.

[5] Ghabri (2020) Value Health, 23 (4), 461-470.

[6] Boyadzieva (2018) Front pharmacol 9, 794.

Acknowledgements: NIL.

Disclosure of Interests: Kunal Shastri is an employee of Fresenius Kabi, Kerise Clarke is an employee of EVERSANA, a company which has received consulting fees from Fresenius Kabi, Margaret Ainslie-Garcia is an employee of EVERSANA, a company which has received consulting fees from Fresenius Kabi, Kirk Szafranski is an employee of EVERSANA, a company which has received consulting fees from Fresenius Kabi, Nicole Ferko is an employee of EVERSANA, a company which has received consulting fees from Fresenius Kabi.