Economic Evaluation of Atezolizumab + Bevacizumab for Hepatocellular Carcinoma

Only direct medical costs, including costs of acquiring drugs, costs attributed to the patient’s health state, costs for the management of adverse events (AEs), and costs for end-of-life care, were analyzed (Table 1). The costs are reported in 2019 US dollars and were inflated to 2019 values using the Medical-Care Inflation data set in Tom’s Inflation Calculator.¹⁶ According to the IMbrave150 trial report,^{5 (link)} patients in the atezolizumab plus bevacizumab group received atezolizumab (1200 mg) plus bevacizumab (15 mg/kg body weight) intravenously every 3 weeks. Patients assigned to the sorafenib group received sorafenib (400 mg) orally twice daily. Treatment continued until disease progression or unacceptable toxicity or, for the immunotherapy regimen group, until 2 years of follow-up. The prices of atezolizumab, bevacizumab, and sorafenib were collected from public databases.^{12 ,13} In the US, the prices of ipilimumab, nivolumab, pembrolizumab, and dabrafenib plus trametinib were discounted by 17% to account for contract pricing.^{17 (link)} To calculate the dosage of bevacizumab, we assumed that a typical patient in the US weighed 71.4 kg.^{18 (link)} After disease progression, 69 of 197 patients (35.0%) in the atezolizumab plus bevacizumab group and 73 of 109 patients (67.0%) in the sorafenib group received subsequent active therapy. The costs associated with subsequent active salvage therapy and the greatest supportive care were $108 336 and $37 084 per patient, respectively, which were estimated from a cost-effectiveness analysis of second-line treatments of advanced HCC.^{14 (link)} The monitoring costs for patients with PFD and patients with PD were $245 per month and $15 308 per month, respectively, which were collected from an economic evaluation of sorafenib for unresectable HCC.^{15 (link)} The cost associated with terminal care was $7893 per patient with advanced HCC.^{14 (link)} The analysis included the costs associated with managing grade 3 or higher AEs, which were extracted from the literature (eTable 3 in the Supplement).^{14 (link),19 (link)}Each health state was assigned a health utility preference on a scale of 0 (death) to 1 (perfect health). The PFD and PD states associated with HCC were 0.76 and 0.68,^{10 (link)} respectively, which were derived from a cost-effectiveness analysis considering patients with HCC. The disutility values due to grade 1 or 2 and grade 3 or 4 AEs were included in this analysis.^{11 (link)} All AEs were assumed to be incurred during the first cycle. The duration-adjusted disutility was subtracted from the baseline PFD utility.