A Cost Analysis of Adverse Event Management of Systemic Therapies for Metastatic Colorectal Cancer on Patients with at Least Two Previous Lines of Treatment in Spain

Objective: First, to estimate the cost associated with the management of grade ≥ 3 adverse events (AEs) experienced by patients with metastatic colorectal cancer (mCRC) who had received late-line therapies (3L+) in Spain. Second, based on the tolerability profiles, the total AEs cost per therapy was estimated. Methods: A cost-analysis was developed to estimate the economic impact associated with the patient management throughout the course of related-AEs of currently available 3L+ therapies for mCRC in Spain (regorafenib, fruquintinib, trifluridine/tipiracil (T/T) and T/T + bevacizumab). The National Health System (NHS) perspective was selected, thus only direct healthcare resources were considered (pharmaceutical treatments, specialist visits, hospital admissions and procedures). For each AE, a total management cost was calculated by multiplying resource consumption by its unitary cost. Finally, for each alternative, the total AEs cost was estimated multiplying the AEs incidence rate by its management cost. Unit costs (€, 2025) were obtained from national databases. AEs incidence rates were obtained from pivotal clinical trials. Anchored comparisons were calculated using a difference-in-differences (DID) approach with best-supportive care as a common reference. Results: Total cost associated with AEs grade ≥ 3 occurring in patients with mCRC receiving 3L+ ranged from € 300.19/patient for the management of hypertension to € 3335.11/patient for increased bilirubin. Adjusting AEs for reported incidences, the total cost was € 284.54 for fruquintinib (FRESCO), € 301.82 for fruquintinib (FRESCO-2), € 749.91 for T/T + bevacizumab (SUNLIGHT), € 750.56 for T/T (SUNLIGHT), € 1383.57 for T/T (RECOURSE) and € 1158.57 for regorafenib (CORRECT). Fruquintinib in the anchored comparison based on FRESCO and FRESCO-2 shows: a cost reduction of € 398.70 and € 360.98 compared to regorafenib (CORRECT), and a cost reduction of € 491.55 and € 453.83 compared to T/T (RECOURSE). Conclusion: The results of this analysis showed that fruquintinib was associated with lower management costs of AEs in patients with mCRC treated in late-line in Spain. Keywords: metastatic colorectal cancer, safety, cost-management