ORIGINAL RESEARCH ARTICLEdi patologie di natura flogistica a carattere cronico e progressivamente disabilitante, caratterizzate da meccanismi patogenetici di natura immunitaria (1). Rientrano in questo gruppo l'artrite reumatoide, le spondiloartropatie, l'artrite giovanile idiopatica, l'artrite psoriasica, la psoriasi, la malattia di Crohn e la colite ulcerosa (2). Sebbene l'incidenza e la prevalenza di queste patologie valutate singolarmente non siano particolarmente elevate (2-5), fatta eccezione per la psoriasi (6), considerate come insieme coinvolgono invece una quota non secondaria della popolazione italiana (prevalenza 3,7%; incidenza 0,2%) (7).In linea con quanto riportato per altre malattie cronicodegenerative (8-11), anche per le IMID i costi diretti sanitari costituiscono un importante capitolo di spesa. Esse esercitano anche un forte impatto sociale poiché, sin dalle fasi inziali, de- The aim of this analysis was to provide an estimate of drug utilization indicators (dose escalation and dose tapering) related to biologic drugs in the chronic treatment of adult patients with Immune-Mediated Inflammatory Diseases (IMIDs). Methods: We conducted an observational retrospective cohort analysis using the Policlinico di Tor Vergata (PTV) database. We considered all biologic drugs dispensed by the PTV hospital pharmacy between January 2010 and December 2015:abatacept, adalimumab, certolizumab, etanercept, golimumab, infliximab (originator and biosimilar), tocilizumab, and ustekinumab were included. Drug dose escalation and dose tapering were calculated and compared with their Defined Daily Dose (DDD). Results: A total of 1803 patients with IMID and biologic drug prescription were analyzed (male: 51.2%). The majority of patients were in the class 36-50 years (n = 612). The median follow-up was 33.8 months . Dermatology was the ward with the largest number of patients (n = 882; 48.9%), followed by rheumatology (n = 619; 34.3%) and gastroenterology (n = 302; 16.8%). Dose escalation was observed in 406 patients (22.5%). Infliximab biosimilar (n = 51) was the biological drug with the highest dose escalation rate (86.3%), followed by infliximab originator (n = 28; 60.3%) and ustekinumab (37.8%). Etanercept was the biological drug with the lowest dose escalation rate (7.4%), followed by golimumab (12.2%) and adalimumab (13.8%). In 677 patients (37.5%) a dose tapering was observed. Etanercept showed the highest rate of patients with dose tapering (41.6%), followed by adalimumab (33.6%).
Conclusions:The results of this analysis show that dose modification is quite common in PTV clinical practice. Considering the strong focus on the pharmaceutical expenditure and the need of cost containment, it is also important to take into account the effect of dose modifications in order to assess the actual treatment cost for biological drugs.