P836 Prospective evaluation of the switch from adalimumab originator to different biosimilars in IBD patients : acceptability and persistance at 1 year

Abstract

Abstract Background The use of biological therapies represents a major source of direct healthcare costs for inflammatory bowel disease (IBD) in industrialised countries. Several adalimumab (ADA) biosimilars are available for Crohn's disease (CD) and ulcerative colitis (UC) patients. The aims of our study were to assess the acceptance of switching from Humira® to different ADA biosimilars in IBD patients, the biosimilar persistence at 1 year, and the acceptability of the switch. Methods From July 2020 to September 2021, we proposed for consecutive and ambulatory IBD patients on maintenance Humira® to switch to one of the five ADA biosimilars available at the time of the study (Amgevita®, Idacio®, Imraldi®, Hulio®, Hyrimoz®) at Lille University Hospital (France). Patients accepting the switch chose a ADA biosimilar with an IBD nurse and were followed prospectively for 1 year. Biosimilar persistence was assessed at 6 and 12 months using the Kaplan-Meier method. Factors associated with switch acceptance and biosimilar persistence were identified by logistic regression tests (Chi-2). Data on efficacy, safety and rate of return to ADA originator were assessed at 6 and 12 months. At 12 months, acceptability of the switch was assessed by a questionnaire. Results 97 patients (84 CD patients; 13 UC patients) were included in the study. 89/97 patients (91.8%, including 76 CD patients) accepted the switch from ADA originator to a biosimilar. Poor opinion of generic drugs was the only factor associated with refusal to switch. At 12 months, 61 patients (71%) were still on ADA biosimilar and 54 patients (60%) were still treated with the biosimilar initially introduced. During the follow-up, the proportion of patients treated with Hulio® remained stable (around 30%), while the proportion of patients treated with Amgevita®, Idacio®, Imraldi® and Hyrimoz® decreased (from 33.7% to 22.5%, from 20.2% to 5.6%, from 8% to 4.5% and from 10.1% to 5.6%, respectively) (Figure 1). One quarter of patients switched back to ADA originator at 12 months. Thirty-seven patients discontinued the treatment. Among them, 22 patients (59.5%) discontinued due to injection site reactions. Clinical remission rates were stable between the baseline and the 6 and 12 months evaluation (94.4%, 88.8% and 89.2% respectively). The switch from ADA originator to a biosimilar was considered acceptable for 31/38 patients (81.6%) evaluated at 12 months. Conclusion A large proportion of IBD patients (91.8%) accepted the switch from ADA originator to a biosimilar and 60% continued ADA biosimilar at 1 year. The high acceptability of the switch encourages the use of ADA biosimilars in clinical practice.