Cost per responder of adalimumab biosimilars versus methotrexate in patients with psoriasis: a real-life experience

Background: Pharmacoeconomic studies examining the cost-effectiveness of adalimumab biosimilars versus methotrexate in real-life settings are limited. Objectives: To assess the cost per responder from the perspective of the National Health System of adalimumab biosimilars versus methotrexate for psoriasis treatment in a real-life setting. Methods: A cost-per responder analysis comparing adalimumab biosimilars MSB11022 (Idacio®) and ABP 501 (Amgevita) versus subcutaneous methotrexate was performed. The incremental cost per responder was calculated by multiplying the cost of treatment (including the discounts, as published in the framework agreement of the Veneto region) and the number needed to treat each therapy. The clinical efficacy measures were defined as being on treatment (i.e., retention rate) at weeks 24 and 52. Results: A total of 712 adult patients with moderate-to-severe chronic plaque psoriasis consecutively admitted to the outpatient clinic from January 2021 to December 2022 were included; 160 were treated with ABP 501 (Amgevita), 250 with MSB11022 (Idacio) and 302 with methotrexate. The retention rates of Amgevita, Idacio and methotrexate at week 24 were 86%, 90% and 78%, and 81%, 82% and 63% at week 52, respectively. The cost per responder at week 24 was €674 for Amgevita, €366 for Idacio and €264 for methotrexate, respectively; at week 52, was €1430 for Amgevita® €799 for Idacio® and €652 for methotrexate, respectively. Conclusions: The real-life cost-effectiveness of biosimilar drugs is largely influenced by discount rates. The week 52 cost-effectiveness of Idacio is comparable to subcutaneous methotrexate. The lowering of the cost of biosimilar drugs makes them a more accessible therapeutic option and they also can be introduced earlier in the treatment of moderate-to-severe psoriasis.