P797 Self-reported efficacy and safety of infliximab and adalimumab biosimilars after non-medical switch in patients with Inflammatory Bowel Disease: Results of a multicenter survey

Bikar, A.(1);Farkas, N.(2);Resál, T.(3);Szepes, Z.(3);Klaudia, F.(3);Vincze, Á.(1);Miheller, P.(4);Molnár , T.(3);Sarlós, P.(1)*;

(1)Medical School- University of Pécs, Division of Gastroenterology- First Department of Medicine, Pécs, Hungary;(2)Medical School- University of Pécs, Institute for Translational Medicine-, Pécs, Hungary;(3)Faculty of Medicine- University of Szeged, First Department of Medicine, Szeged, Hungary;(4)Semmelweis University- Budapest, Department of Surgery- Transplantation and Gastroenterology, Budapest, Hungary;


Several studies have proven similarity in terms of efficacy and safety between infliximab (IFX) or adalimumab (ADA) biosimilars and their corresponding originators. However, there is still a paucity of data on the impact of switching from an originator to a biosimilar on patients’ subjective disease control in clinical practice. In Hungary, a mandatory non-medical switch program regarding anti-TNFs was launched in 2021. We aimed to assess symptom control and perception of adverse events following non-medical switch in patients with inflammatory bowel disease (IBD).


In this cross-sectional, questionnaire-based study, Hungarian patients with IBD who switched from infliximab originator to biosimilar GP1111 or from adalimumab originator to biosimilar GP2017 after receiving at least one dose of biosimilar were interviewed. The subjective efficacy was measured using a 10-point interval rating scale, and adverse events were assessed. The difference in efficacy before and after the switch was calculated and compared within and between the two drugs. All statistical analysis was performed using R Statistical Software.


A total of 179 patients were interviewed (median age 41 years, interquartile range 32 to 47; 135 and 44 patients with Crohn’s disease and ulcerative colitis, respectively). There were 73 ADA and 106 IFX switches in our cohort. The subjective efficacy of IFX biosimilar was rated lower compared to IFX reference product (8.72±1.68 vs. 7.77±2.34; p=0.001). The ADA biosimilar was rated higher than their reference product (9.02±1.61 vs. 8.42±1.93; p=0.017). Comparing the satisfaction of non-medical switch between biosimilar groups, patients receiving ADA were more satisfied with the new treatment as patients in the IFX group (p=0.032). The incidence of new perceived adverse events was 85 % in the ADA and 55 % in the IFX group (p<0.001). 66 % of patients on ADA treatment reported pain at the subcutaneous injection site.


Our study confirmed the efficacy of the switch to a biosimilar in the case of ADA, while reduced efficacy was experienced with IFX biosimilar. Based on the different adverse event profiles of biosimilars, the importance of switching the product for medical reasons should be emphasized.