A single-centre analysis of a biosimilar switching programme for adalimumab in inflammatory bowel disease

Rabbitt, Louise, Keogh, Áine, Duane, Linda, Ferguson, John, Hobbins, Anna, McGuire, Brian E., et al. A single-centre analysis of a biosimilar switching programme for adalimumab in inflammatory bowel disease. British Journal of Clinical Pharmacology, https://doi.org/10.1002/bcp.70086

Abstract

Aims Amgevita is a licensed biosimilar to adalimumab, having demonstrated high pharmacokinetic and clinical similarity to Humira. Switching to a lower-cost medicine may elicit a nocebo effect, whereby expectations of poorer efficacy impact outcomes despite pharmacological similarity. This prospective cohort study examined clinical and economic outcomes and associated psychosocial variables in a group of patients undergoing a nonmedical switch to biosimilar adalimumab. Methods Patients with inflammatory bowel disease (IBD) were followed before and after switching from Humira to Amgevita. Objective disease activity was assessed pre- and post-switch using the Harvey–Bradshaw Index (Crohn's disease) or partial Mayo score (ulcerative colitis), faecal calprotectin and C-reactive protein. Subjective symptom burden was measured using the IBD Control Questionnaire (IBDCQ). Pre-switch, health anxiety was measured using the Health Anxiety Index (HAI). Results In total, 64 patients aged 18–67 were enrolled. IBDCQ scores marginally improved post-switch (13.33 vs, 12.49, P = .043), with no significant changes in objective disease activity scores, faecal calprotectin or C-reactive protein. Sixteen patients reported 17 new adverse events within 4 weeks. Logistic regression revealed a significant relationship between HAI scores and adverse events (P = .0079); each unit increase in HAI score increased the odds of reporting an adverse event by 21%. Drug cost savings for the 64 patients over 8 weeks totalled €143 958. Conclusion Switching to biosimilar adalimumab did not affect disease control or quality of life. 25% of patients developed new side effects, particularly those with high levels of health anxiety. Significant cost savings were achieved.

Funder

Wellcome Trust
Health Research Board

Publisher

Wiley

Rights

Attribution 4.0 International

cb

Collections

Pharmacology & Therapeutics (Scholarly Articles)