Switching to Subcutaneous Infliximab Biosimilar CT-P13 Significantly Lowered Indirect Costs for Patients

Switching from intravenous to subcutaneous infliximab biosimilar, CT-P13, was broadly cost neutral to healthcare providers, according to a real-world analysis published in BMJ Open Gastroenterology.¹ As the subcutaneous preparations have higher direct costs, switching reduces cost and allows for efficient use of intravenous infusion units.

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In the United Kingdom (UK), the average cost of treating patients with inflammatory bowel disease (IBD), such as those with Chron’s disease and ulcerative colitis, has been estimated to range from £3000 to £6000 per patient per year.²

“We have since seen the development and introduction of biosimilar biologics, which are associated with significant per patient cost savings due to very competitive pricing in the UK,” Isabel Carbery, associated with the Leeds Teaching Hospitals NHS Trust in Leeds, UK, and a team of investigators, stated. “Subcutaneous CT-P13 has been shown to have similar efficacy and safety in the treatment of IBD in both trials and real-world settings. There is a price differential between the intravenous and subcutaneous formulations of CT-P13, but the financial impact of switching existing intravenous patients to subcutaneous CT-P13 on the health service and wider society is currently unclear.”

The direct and indirect costs of switching patients with IBD from intravenous to subcutaneous CT-P13 were evaluated in patients receiving care at Leeds Teaching Hospitals Trust, UK. Patients receiving the standard dose of the drug (5 mg/kg every 8 weeks) were eligible to switch. Of these patients, 58% (n = 98/168) switched within a 3-month span and were subsequently classified as intravenous or subcutaneous.

Total annual costs were calculated using both direct and indirect costs. Direct costs included the average number of infusions or injections annually, medication costs, and infusion unit costs. Indirect costs were determined using travel data, such as mode of transport, parking costs, time spent on travel, and employment status.

The total annual intravenous cost for these patients prior to switching was £689,507.04, with £653,671.20 reported as direct costs and £35,835.84 linked to indirect costs. After the switch, with 70 patients receiving intravenous infusions and 98 receiving subcutaneous, the total annual cost was £674,922.83 (direct = £654 563, indirect = £20 359.83). This resulted in a £891.80 higher cost to healthcare providers. An intention to treat analysis reported a total annual cost of of £665,961.01, with £655,200 reported as direct costs and £10,761.01 were indirect. This resulted in £1528.80 higher cost to providers.

However, a significant decrease in indirect costs was observed in patients switching to subcutaneous CT-P13 (£213.31 to £121.19), which was attributed to lower total costs overall.

Investigators were unable to obtain travel and employment data from a proportion of patients, leading them to estimate these costs to the entire cohort. However, they used actual hospital distance for each patient to calculate the travel costs. Further, employment costs were determined using the average national hourly wage, which may have over or underestimated the wages of this patient population. The findings may have been susceptible to recall bias based on the retrospective nature of the questionnaire. A sensitivity analysis was performed to account for the variance of direct costs in different locations both within the UK or internationally. However, drug costs outside of the UK may vary.

“While the subcutaneous option has higher drug costs, a switch to subcutaneous allows for more efficient running of intravenous induction therapies by reducing demand on the infusion unit and reduces indirect costs to the patient in terms of travel, parking and potential loss of working hours,” investigators concluded.

References

1. ^{Carbery I, Burdge G, Clark T, et al. Impact on direct and indirect costs of switching patients with inflammatory bowel disease from intravenous to subcutaneous infliximab (CT-P13). BMJ Open Gastroenterol. 2023;10(1):e001105. doi:10.1136/bmjgast-2023-001105}
2. ^{Ghosh N, Premchand P. A UK cost of care model for inflammatory bowel disease. Frontline Gastroenterol 2015;6:169–74. doi:10.1136/flgastro-2014-100514}