Replacement of Adalimumab Originator to Adalimumab Biosimilar for a Non-Medical Reason in Patients with Inflammatory Bowel Disease: A Real-life Comparison of Adalimumab Biosimilars Currently Available in Italy

Background and aims: Adalimumab (ADA) biosimilars have been included into the therapeutic armamentarium of inflammatory bowel disease (IBD); however, comparative data on the efficacy and safety of the different ADA biosimilars after replacing the ADA originator for a non-medical reason remains scarce. We aimed to compare in a real-life setting the efficacy and safety of four ADA biosimilars SB5, APB501, GP2017, and MSB11022 in IBD patients after replacing the originator for a non-medical reason. Methods: A multicenter retrospective study was performed on consecutive IBD patients, analyzing clinical, laboratory, and endoscopic data. The primary endpoints of the study were maintenance of clinical remission and safety of the different biosimilars. Results: 153 patients were enrolled, 26 with UC and 127 with CD. Clinical remission was maintained in 124 out of 153 (81%) patients after a median (IQR) follow-up of 12 (6-24) months, without any significant difference between the four ADA biosimilars. ADA biosimilars dosage was optimized in five patients (3.3%). Loss of remission was significantly higher in UC patients (10/26 patients, 38.5%) than in CD patients (19/127 patients, 14.9%, p<0.025). Adverse events occurred in 12 (7.9%) patients; the large majority were mild. Conclusions: No difference in efficacy and safety was found between ADA biosimilars when used to replace the ADA originator for a non-medical reason. However, in UC patients the replacement of ADA originator for this reason should be carefully assessed.