Efficacy of transarterial radioembolization using Y-90 resin microspheres versus atezolizumab-bevacizumab in unresectable hepatocellular carcinoma: A matching-adjusted indirect comparison

Abstract

Introduction: No head-to-head trials compared the efficacy of transarterial radioembolization (TARE, also known as selective internal radiation therapy) to combination immunotherapy in hepatocellular carcinoma (HCC). The analysis objective was to compare effectiveness outcomes of TARE using Y-90 resin microspheres and atezolizumab-bevacizumab (AB) in advanced unresectable HCC.

Methods: Patient-level data from SARAH randomized controlled trial for TARE and aggregate real-world data from AB-real study were used in an unanchored matching-adjusted indirect comparison. The basecase analysis used per-protocol data from SARAH; intention-to-treat data were used in sensitivity analyses. The following prognostic variables and effect modifiers were identified from literature: cause of disease, macrovascular invasion, Eastern Cooperative Oncology Group Performance Status, alpha-fetoprotein level and albumin-bilirubin score. Weights were assigned to patients from SARAH to balance baseline characteristics across studies and reflect characteristics of AB-real patients. Overall survival (OS), progression-free survival (PFS) and response rates (overall response rates [ORR]) were calculated and compared.

Results: The analysis of OS and PFS included 140 patients receiving TARE and 131 for the analysis of response rates, compared to 202 receiving AB. Median OS was 15.0 and 14.9 months for TARE and AB, respectively (HR=0.980; 95% confidence interval [CI]: 0.658-1.461; p-value=0.922). Median PFS was 4.4 and 6.8 months for TARE and AB, respectively (HR=0.745; 95%CI: 0.544-1.022; p-value=0.068). ORR were 19.8% and 25% with TARE and AB, respectively (OR for AB=1.386, 95%CI: 0.746-2.668; p-value=0.306). Sensitivity analyses generated similar results.

Conclusion: In HCC patients receiving treatment, TARE using Y-90 resin microspheres may achieve comparable effectiveness outcomes compared with AB.

Keywords: Atezolizumab; Bevacizumab; Hepatocellular carcinoma; Matching-adjusted indirect comparison; Real world; SARAH; Selective internal radiation therapy; Transarterial radioembolization.