Presentation (CTI)

OBJECTIVES: Inflammatory bowel disease (IBD) is a chronic disease involving long-term care with multiple therapeutic strategies. Infliximab is a widely used biological therapy and available in both intravenous (IV) and subcutaneous (SC) formulations. Despite equivalent clinical efficacy and reduced organizational burden, the environmental footprint of switching forms across the IBD care pathway remains unexplored. This study assesses the environmental impact of the switch intervention from IV to SC by comparing carbon emissions across IBD care pathway in France.
METHODS: The analysis followed the Shift Project framework, using a bottom-up approach to quantify carbon emissions per patient including patient transport, treatment administration, and the infliximab carbon footprint. The model compared scenarios with and without switch to SC infliximab for eligible patients over one year. Data were derived from the Shift Project and complemented with other sources including the French Agency for Ecological Transition.
RESULTS: At the patient level, the annual carbon footprint was estimated at 542 kgCO2e for IV and 579 kgCO2e for SC infliximab. At the scale of the target population, switching from IV to SC resulted in an increase of 3% in total carbon emissions representing 524 tCO2e per year. This increase was driven by a higher drug-specific carbon footprint for SC compared to IV formulation respectively at 13,312 and 10,799 tCO2e. However, SC infliximab implied emission reductions in patient transport (-22%) and treatment administration (-38%), explained by a lower frequency of hospital-based infusions.
CONCLUSIONS: SC infliximab reduces patient transport and treatment administration emissions across the IBD care pathway, yet its heavier drug-specific carbon footprint leads to an increase of the overall emissions. A comprehensive environmental assessment integrating additional emission sources, such as day hospitalization, is required to fully capture the environmental impact of this intervention.