Background: Since 2006 more than 50 biosimilars have been authorized for use in Spain ^[1] . Although national incentives are not present in Spain (due to its decentralized healthcare system), regional incentives for biosimilar use may help to increase the uptake of biosimilars, particularly in hospitals ^[2] . The adherence to regional guidelines may drastically vary between hospitals due to limited physician information and hesitancy towards biosimilars from the perspective of physicians and patients ^[2] . Therefore, continued efforts to understand the benefits associated with the use of biosimilars can help overcome barriers and help to increase uptake as new biosimilars come into the Spanish market ^[2] . A tocilizumab (an interleukin-6 inhibitor [IL-6i]) biosimilar was recently launched which may help lower healthcare spending on tocilizumab and/or expand patient access.

Objectives: To develop a model to evaluate the budget impact and expanded access associated with a novel tocilizumab biosimilar in Spain.

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 world 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 including 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 (COVID-19 was excluded due to currently low incidence and prevalence). Percent of patients utilizing IL-6i was informed by a peer-reviewed study reporting the extent of IL-6i use in a cohort of patients in Spain. Biosimilar tocilizumab was assumed to occupy 50%, 75%, and 100% of the market in year 1, year 2, and year 3, respectively, across indications. Biosimilar tocilizumab was assumed to have a 30% 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 while remaining budget neutral.

Results: Based on the inputs for prevalence, incidence, and percent IL-6i users, an estimated 12,046 patients were treated with IL-6i in Spain. In year 1, assuming a 50% market share of a tocilizumab biosimilar, the budget savings were €23.6 million with 2,581 additional patients treated (15% increase in patient access nationally). In year 2 (75% biosimilar market share), the budget savings were €36.0 million with an additional 3,940 patients treated (23% increase) compared to a world without biosimilar tocilizumab. In year 3, assuming exclusive use of a tocilizumab biosimilar, the budget savings were €49.9 million, with 5,456 additional patients treated (30% increase). The cumulative savings across the time horizon (3 years) was €109.5 million, representing an additional 11,977 patients that could be treated.

Conclusion: The use of a tocilizumab biosimilar was projected to result in substantial savings in Spain, 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] García-Goño (2021) Pharmaceuticals (Basel, Switzerland) 14(4), 348.

[2] Lobo (2021) Pharmaceuticals (Basel, Switzerland) 14(3), 283.

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.