1ISG-025 Budget impact analysis of biosimilar adalimumab versus reference adalimumab

Background and importance Biological treatments represent a great opportunity but their increasing and widespread use is causing sustainability problems in health systems due to their high cost. Emergence of biosimilars can lead to significant savings for health systems. Aim and objectives The aim of this study is to analyse the impact of the introduction of the biosimilar adalimumab (BA) (Hyrimoz) in three different scenarios, to choose the most convenient. Material and methods Firstly, we took into account all patients treated with the reference adalimumab (RA) between 2013 and 2018 to calculate the average incidence for every quarter. Also, we calculated prevalence on 31 December 2018. We then made a quarterly consumption forecast for the next three years (2019–2021). Secondly, we created an excel model for three possible scenarios: (1) all patients treated with RA, (2) the introduction of BA only in new patients with old patients continuing with RA or (3) all patients treated with BA. In every scenario, we calculate costs of buying adalimumab in each year. Finally, to assess the robustness of the data, different deterministic sensitivity analyses were conducted changing ±10% the three variables considered to have more impact in our model (price of adalimumab, incidence and prevalence). Also, an extreme analysis was performed for the best and worst conditions. Results Despite the increasing costs in all scenarios due to a growing incidence, costs would vary from 4 million in 3 years (scenario 1), 3.5 million (scenario 2), to 2.7 million (scenario 3). The choice of the different scenarios would mean savings of 11.5–31.8%, depending on the number of patients who were treated with BA. Sensitivity analyses showed that the cost of adalimumab was the most important factor in the final cost results. Analysis of extreme conditions showed a 20% variation from base case with savings of about 11.5% (scenario 2) and 30% (scenario 3). The most convenient was scenario 3 (change patients already treated with RA and treat new patients with BA). Conclusion and relevance Despite scenario 3 providing the greatest savings (making it possible to treat a large number of patients), the authorities decided not to change patients currently treated with RA, loosing savings of about 20.33%. References and/or acknowledgements Conflict of interest No conflict of interest