Introduction

In Australian patients receiving intravenous (IV) infliximab (IFX) treatment, 44% of patients do not respond to standard regimen and require dose escalation within a year. The REMSWITCH (6-month evaluation) and REMSWITCH-LT (18-months evaluation) investigated the effectiveness of switching from IV to subcutaneous (SC) IFX in patients with inflammatory bowel disease (IBD) who received standard and dose-escalated IV regimen. The two studies concluded that a fixed dose of 120 mg Q2W is feasible, safe and well-accepted leading to a low risk of long-term relapse in patients with escalated IV doses except for those on 10mg/kg/4weeks regimen. In this study, we developed a model to estimate the financial implications of switching.

Aims & Methods

Clinical efficacy parameters were derived from the REMSWITCH and REMSWITCH-LT studies and applied to the Australian context. Number of Australian patients who are on IFX, the proportion of patients on dose escalated regimen, and cost parameters were identified from the published literature or publicly available resources. A financial model was developed based on the assumption that a cohort of patients will receive either IV or SC IFX, and the analysis concluded with the cost difference.

Results

The model assumes that a total of 5.6K patients are receiving IV IFX, with 44.2% of them receiving dose escalation and/or shortened interval of IV IFX. The model produced 6 months and 12 months results, suggesting savings between 582 and 882 AUD per patient, respectively, and equates to a yearly societal savings of 5 million AUD.

Conclusion

IFX SC deserves premium over IFX IV, given that the novel formulation offers tangible and intangible benefits that originator Remicade and biosimilars cannot provide. There is a concern regarding the affordability of SC IFX because it is generally priced higher than IV IFX, which has many biosimilars on the market. However, this study asserts that fixed dosing of 120mg of IFX is cost-saving for society, considering highly prevalent practice of dose escalation and/or shortened intervals of IFX regimen.