P555 Outcomes of multiswitching from original infliximab to biosimilars in patients with inflammatory bowel disease

Nascimento, C.(1);Revés, J.(1);Morão, B.(1);Frias Gomes, C.(1);Gouveia, C.(1);Palmela, C.(1);Roque Ramos, L.(1);Fidalgo, C.(1);Cravo, M.(1);Glória, L.(1);Torres, J.(1);

(1)Hospital Beatriz Ângelo, Gastrenterology, Loures, Portugal

Background

Since 2013 multiple Infliximab (IFX) biosimilars became available in the market. While there is evidence that switching from original IFX (RemicadeÒ)  to an approved biosimilar product is safe and effective, little is known about outcomes of reverse switching and multiple switching among biosimilars in IBD patients.  As the access to biosimilars at competitive prices increases, it is necessary to evaluate multiple switches to provide data on their interchangeability. Our aim was to evaluate the efficacy, safety and pharmacokinetic profile in a cohort of IBD patients who experienced multiple switches.

Methods

This is a cohort retrospective observational study, enrolling patients with IBD who were successively switched from original IFX to one or more biosimilars (multiswitching).  We compared clinical disease activity, assessed using the Harvey-Bradshaw index (HBI) and partial Mayo Score (pMS), biochemical markers (hemoglobin, C-reactive protein (CRP) and albumin), IFX trough levels (ITL) and anti-IFX antibodies (ADA) immediately before and after multiswitching. Adverse and infusion-related events leading to drug discontinuation were registered.

Results

We included 26 patients (59% male, mean age 35±12 years), 85% (n=22) with Crohn’s Disease (CD) and 15% (n=4) with ulcerative colitis (UC) or indeterminate colitis. The mean disease duration from diagnosis was 9±6 years. According to Montreal classification, most patients were A2 (68%), had ileocolonic disease (L1 51%; L2 9%; L3 50%) and an inflammatory phenotype (B1 41%; B2 23% and B3 36%). Perianal disease was present in 44%. Half of patients had pancolitis (E3). About 51% of the patients had a prior resection surgery and 27% was on combination therapy when the first switch occurred. In 35% (n=9) of the patients three switches were observed. The mean follow-up from the first switch was 15±18 months. There was no significant difference in the proportion of patients in clinical remission (HBI < 5; Mayo score < 3) (91% vs 96%, p=NS). We found no differences in laboratory markers such as CRP (0,79 vs 0,67 mg/dl, p=NS), hemoglobin (13,83 vs 13,75g/dl, p=NS) and albumin (3,98 vs 4,37mg/dl, p=NS) before and after the multiswitching. No significant difference was observed in mean ITL (4,9 vs 4,05 μg/mL, p=NS) or in the proportion of patients with ITL>3ug/ml (p=0.205). None of patients developed ADA, infusion-related events or loss of response leading to drug discontinuation. During our follow-up none of patients was operated. Drug persistence was 100%.

Conclusion

In our cohort, no significant changes in efficacy, safety or immunogenicity were observed when IBD patients experienced multiple switches between the original IFX and its biosimilars.