Abstract
In the last years, adalimumab biosimilars have represented a commonly used alternative to the originator agent in the treatment of moderate to severe hidradenitis suppurativa. As of today, studies investigating the switch from adalimumab originator to biosimilar, following pharmacoeconomic policies, are lacking. Herein we present a real-life setting retrospective study aimed at assessing the safety and efficacy of this switch in 37 patients, evaluated for 12 months in terms of IHS4 (International Hidradenitis Suppurativa Severity Score System) and HiSCR (Hidradenitis Suppurativa Clinical Response). Overall, no significant differences emerge between adalimumab originator and biosimilar in terms of clinical response following non-medical switch. High discontinuation rates (43.2%) raise questions on patients' compliance to the new drug regimen, as severe pain at the injection site represents a substantial cause of biosimilar discontinuation (i.e., 31.5% of the cases). In selected cases, rechallenge with adalimumab originator may represent a valid option, as 66.6% (n = 8) of the patients who switched back to the former agent have benefited in terms of tolerability and efficacy. Carefully integrating pharmacoeconomic policies with a thorough assessment regarding the benefit-risk ratio of a nonmedical switch from originator to biosimilars remains essential to provide each HS patient with the best therapeutic option.