Abstract
Background
Biological medicines account for a significant cost to healthcare systems. With the advent of anti-tumour necrosis factor biosimilars, switching from originator to biosimilar has enabled cost saving in inflammatory bowel disease (IBD) without compromising disease control. However, with more biosimilars entering the market, the effect on IBD activity and pharmacokinetics (PK) of a second switch to another biosimilar is uncertain. This study aims to assess the effect on disease activity and drug levels associated with switching from infliximab (IFX) biosimilar Remsima® (Celltrion, Hungary) to another biosimilar, Flixabi® (Samsung Bioepis, The Netherlands), and to compare those switching for the first and second time.
Methods
All IBD patients on IFX biosimilar Remsima® were prospectively followed during their switch to Flixabi® in a single centre. Baseline data including C-reactive protein (CRP), trough IFX level, and clinical disease activity indices were collected; Harvey Bradshaw Index for Crohn’s disease (CD) and Simple Clinical Colitis Activity Index for ulcerative colitis (UC). These indices were repeated after at least two infusions of Flixabi®.
Results
221 patients (179 CD, 42 UC) on stable IFX treatment were included in the study. 174 (79%) were on a concomitant immunomodulator. 5 (2%) patients ceased IFX prior to follow-up due to sustained remission, and 3 (1%) patients discontinued due to factors not directly related to drug or disease. 112 patients had PK analysis performed pre and post switch. An increase in IFX trough level was observed after switching IFX biosimilars; baseline median (IQR) trough level of 4.5µg/ml (2.9–6.3) compared with post switch of 5.1µg/ml (3.4–7.0) (p = 0.02). There was no difference in clinical scores or CRP post switch, and no new anti-IFX antibodies were detected. 107 patients (48%) were switching IFX agent for the second time, of which 51 had PK analysis performed. A similar increase in median IFX trough level was observed post switch in those switching for the first (4.7 vs. 6.1 µg/ml, p = 0.03) and second (4.0 vs. 4.5µg/ml, p = 0.05) times (Figure 1). No change in clinical disease activity or CRP occurred in either group. Concomitant immunomodulator and disease classification had no impact on change in IFX level (p = 0.72 and 0.37, respectively, on univariate analysis).
Conclusion
In a cohort of IBD patients switching to a new IFX biosimilar either for the first or second time, an increase in IFX level was observed with no impact on clinical and biochemical disease activity indices. Switching IFX biosimilars in IBD appears safe in the short term with respect to maintaining drug pharmacokinetic profile and disease control whether switching for the first or second time.
P279. Fecal calprotectin is elevated with clinical disease activity during pregnancy in women with Inflammatory Bowel Disease
