Total cost of care of immune-oncology treatments for unresectable hepatocellular carcinoma: A Singapore healthcare perspective analysis.

642 Background: Tremelimumab + durvalumab (STRIDE) and atezolizumab + bevacizumab are recommended first-line immune-oncology treatment options for unresectable hepatocellular carcinoma (uHCC). This study aimed to quantify the total economic burden to the Singapore healthcare system of treating patients with uHCC using STRIDE versus atezolizumab + bevacizumab. Methods: A model was developed to estimate the total cost of care of using STRIDE or atezolizumab + bevacizumab, which followed patients with uHCC eligible for first-line systemic therapy, considering direct medical costs. Costs considered in the model included treatment acquisition and administration, endoscopy, healthcare resource use, and cost for treating grade ≥3 treatment-emergent adverse events (TEAEs). Data on treatment regimens and TEAEs were taken from the HIMALAYA (STRIDE) and IMbrave150 (atezolizumab + bevacizumab) trials. Resource use rates were based on an average of 168 days treatment for both regimens. All costs were obtained from Singaporean sources. Results: The total cost of care for STRIDE and atezolizumab + bevacizumab was estimated at SGD$40,277 (USD$30,932) and SGD$43,605 (USD$33,487) per patient, respectively. This translates into an average cost savings of SGD$3,328 (USD$2,555]) per patient when treated with STRIDE compared to atezolizumab + bevacizumab. The main driver of cost savings was treatment acquisition and administration (-SGD$1,917 [-USD$1,472], -6%) though lower costs were also associated with resource use (-SGD$927 [-USD$712], -8%), endoscopy (-SGD$342 [-USD$263], -77%) and TEAE management (-SGD$141 [-USD$108], -74%). Assuming an incident population of 260 patients eligible for treatment, the total burden was estimated at SGD$10,489,604 (USD$8,055,696) when all patients were treated with STRIDE, and SGD$11,356,273 (USD$8,721,271) when treated with atezolizumab + bevacizumab (Table). The incremental cost offset to the health plan was SGD$866,669 (USD$665,575) when treated with STRIDE. Conclusions: This study suggests that STRIDE offers cost savings over atezolizumab + bevacizumab for uHCC treatment in the Singapore healthcare system. Additional real-world evidence studies are warranted to capture the long-term survival benefits and associated treatment costs. Annual cost of care based on 260 patients receiving first-line immune-oncology treatment. Category STRIDE Atezolizumab + Bevacizumab Incremental difference Endoscopy costs $26,358 $115,555 -$89,197 Resource Use costs* $2,607,000 $2,848,307 -$241,307 Adverse events costs $12,899 $49,716 -$36,817 Treatment acquisition and administration $7,843,347 $8,342,696 -$499,349 TOTAL $10,489,604 $11,356,273 -$866,669 All costs in SGD$. *Includes: physician visits; laboratory and radiological tests; and hospitalisation.