Costs of Adverse Event Management Associated with First-Line Cetuximab or Panitumumab in Metastatic Colorectal Cancer...

Introduction: In Saudi Arabia, patients with metastatic colorectal cancer (mCRC) with wild-type RAS mutations may be treated with either cetuximab plus chemotherapy (CET + CT) or panitumumab plus chemotherapy (PAN + CT), which are epidermal growth factor receptor (EGFR) antibodies. This study calculated the costs of adverse event (AE) management linked to anti-EGFR treatment in Saudi Arabia's national health budget from payer and societal perspectives. Methods: An adaptation of a global model developed in Microsoft Excel® was performed to estimate the costs of AE management associated with the first-line treatment (CET + CT and PAN + CT) of RAS wild-type mCRC patients in Saudi healthcare settings. The frequencies of common and highly common AEs were sourced from the summaries of product characteristics of CET and PAN, whereas AE severity was captured from a meta-analysis. Unit costs in Saudi Riyal (SAR) were obtained from the National Guard of Health Affairs and Ministry of Health 2024 price lists. The model assumptions, inputs, and results were validated using a local Delphi panel. Results: Within the Saudi payer perspective model, treatment with CET + CT vs PAN + CT resulted in average population cost savings of SAR 9 246 133 (4 741 606 international dollars [Intl $\left]\right)andper-patientcostsavingsofSAR20\hspace{0.17em}321(Intl$ 10 421) for severe AEs, and average population cost savings of SAR 16 039 427 (Intl $8\hspace{0.17em}225\hspace{0.17em}347)andper-patientcostsavingsofSAR35\hspace{0.17em}251(Intl$ 18 077) for all-grade AEs. On the other hand, within the Saudi societal perspective model, treatment with CET + CT vs PAN + CT resulted in average population cost savings of SAR 11 386 314 (Intl $5\hspace{0.17em}839\hspace{0.17em}135)andper-patientcostsavingsofSAR25\hspace{0.17em}025(Intl$ 12 833) for severe AEs, while resulting in average population cost savings of SAR 18 179 608 (Intl $9\hspace{0.17em}322\hspace{0.17em}875\left)andperpatientcostsavingsofSAR39\hspace{0.17em}955\right(Intl$ 20 489) for all grade AEs. Conclusion: The CET + CT regimen was associated with a lower AE frequency than the PAN + CT regimen for the treatment of untreated RAS wild-type mCRC patients, thus resulting in AE management cost savings from both the Saudi payer and societal perspectives. These substantial cost savings may mitigate the financial burden of mCRC in Saudi healthcare settings.