Introduction
Subcutaneous (SC) Infliximab (IFX) is non-inferior to intravenous (IV) IFX, for maintenance of remission in inflammatory bowel disease (IBD) (1). There are limited data on factors affecting the decisions of patients who choose SC administration of biologics (2, 3). Our centre offered suitable patients SC IFX from November 2022.
Aims & Methods
(1) Determine disease-related, economic, social and personal factors that affect the decision of a patient with IBD to transition from IV to SC administration of IFX.
(2) Assess effects of SC administration on pharmacokinetics and disease control. Participants completed a questionnaire on their IBD history, personal and financial circumstances, and reasons for electing or declining to transition. Clinical and biochemical data were retrieved from the electronic patient record (EPR). A bivariable logistic regression model was used to determine factors associated with electing to transition.
Results
144 patients were offered the opportunity to transition during the study period. 80 (55.5%) agreed to transition, 64 (44.5%) declined. 101 patients (70.1%) agreed to participate in the study. 59.4% were male, 67.3% had Crohn’s disease. Age ranged was 18-82 (median 41) years. Infusion frequency was every 4 (9.8%), 6 (22.8%), 7 (2.0%), or 8 weeks (65.4%). 76% were employed/self-employed, 41.6% had a medical card and 44.6% had private health insurance. Median (IQR) travel time was 90 mins (40, 130). 48 patients (47.5%) reported that they missed school/work for their infusions. At baseline, median (IQR) laboratory results were CRP 1.2mg/L (0.6, 2.7), IFX trough 7.4mg/mL (4.9, 11.8), faecal calprotectin 39 mg/g (10, 98), IBD-Control 14 (13, 16). 8 weeks after first SC dose, median (IQR) results (n=36) were CRP 1.1mg/L (0.8, 2.0) IFX trough 17.8mg/mL (12.5, 21.4), IBD-Control 16 (14, 16). The strongest reasons to transition (% agree/ strongly agree on five-point Likert) were, “I want to transition because it will…”
(1) reduce my travel time (94.5%),
(2) fit my work/life balance better (87.3%) and
(3) reduce my time away from work/school (74.5%). The strongest reasons against transition were,
(1)I would miss having my bloods checked regularly (84.8%),
(2) I feel safer attending the infusion unit (80.4%),
(3) I would not be able to voice concerns about my treatment as easily (80.4%) and
(4) I would miss regular contact with a healthcare professional (69.6%). Table 1 shows results of binary logistic regression used to determine factors associated with the likelihood of electing to transition.
| Variable | OR | p |
| Age (years) | 1.01 | 0.06 |
| Sex (male = 1) | 0.82 | 0.70 |
| IBD Type (CD = 1) | 0.65 | 0.46 |
| Medical Card | 2.88 | 0.13 |
| Health Insurance | 0.33 | 0.05 |
| Drug Payment Scheme | 4.99 | 0.03 |
| Travel Time | 1.01 | 0.22 |
| IBD Control | 1.01 | 0.85 |
| Missing School/Work for Infusion | 3.78 | 0.04 |
Conclusion
SC IFX is safe, effective and well-tolerated by those who choose to transition. It is attractive to many patients, because attending for IV infusions can interrupt their employment, education and family life, but cost is a significant barrier for some patients. IBD teams must be adequately resourced to assure patients who transition that they will continue to have ready access to high-quality medical care and disease monitoring. Discrepancies in healthcare markets may provide a perverse incentive to continue receiving IV biologic, for those who would prefer SC.
References
1. Schreiber S, Ben-Horin S, Leszczyszyn J, Dudkowiak R, Lahat A, Gawdis-Wojnarska B, et al. Randomized Controlled Trial: Subcutaneous vs Intravenous Infliximab CT-P13 Maintenance in Inflammatory Bowel Disease. Gastroenterology. 2021;160(7):2340-53.
2. Remy C, Caron B, Gouynou C, Haghnejad V, Jeanbert E, Netter P, et al. Inflammatory Bowel Disease Patients’ Acceptance for Switching from Intravenous Infliximab or Vedolizumab to Subcutaneous Formulation: The Nancy Experience. Journal of Clinical Medicine. 2022;11(24):7296.
3. Ventress E, Young D, Rahmany S, Harris C, Bettey M, Smith T, et al. Transitioning from Intravenous to Subcutaneous Vedolizumab in Patients with Inflammatory Bowel Disease [TRAVELESS]. Journal of Crohn's and Colitis. 2022;16(6):911-21.