Real-world comparison of atezolizumab/bevacizumab vs durvalumab/tremelimumab in decompensated hepatocellular carcinoma.

e16159 Background: Pivotal trials established atezolizumab-bevacizumab and durvalumab-tremelimumab as first-line therapies for unresectable hepatocellular carcinoma (HCC). Atezolizumab plus bevacizumab demonstrated superior survival outcomes compared to sorafenib for unresectable HCC in the IMbrave150 trial in 2020, while durvalumab plus tremelimumab showed superior survival in the HIMALAYA trial in 2022. However, data on head-to-head comparison of these two combinations as first-line systemic therapy for the patient with decompensated HCC are limited. This study aims to compare survival outcomes between these two treatment regimens in decompensated HCC patients to address a critical gap in the current literature, as decompensated patients have largely been excluded from clinical trials. Methods: This retrospective study utilized electronic health records from 146 U.S. healthcare organizations within the TriNetX Network. Adults aged ≥21 years diagnosed with decompensated HCC receiving atezolizumab/bevacizumab and durvalumab/tremelimumab from 10/21/2022 to 8/20/2024 were included. The comparison group received atezolizumab/bevacizumab, and the control group received durvalumab/tremelimumab. The primary outcome was all-cause mortality. A 1:1 propensity score matching was conducted to balance baseline characteristics (age, gender, race/ethnicity, lab results including liver function tests, platelet counts, INR, gamma glutamyl transferase, alpha-fetoprotein, and underlying liver diseases). Kaplan–Meier survival analysis and Cox regression was used to estimate the mortality risk. Subgroup analysis was stratified by HCC etiology. Results: A total of 302 and 664 patients received durvalumab/tremelimumab, atezolizumab/bevacizumab, respectively. After propensity matching, 253 patients per group were included. Median OS was 283 days with durvalumab/tremelimumab and 391 days with atezolizumab/bevacizumab. The two treatment regimens showed no significant difference in survival (hazard ratio [HR]: 0.875, 95% confidence intervals [CI] 0.696–1.101, p=0.254). Subgroup analyses demonstrated no significant differences in survival between the two groups of patients in MASLD (HR: 0.698, 95% CI: 0.468–1.040), alcohol associated liver disease (HR: 0.821, 95% CI: 0.603–1.118), and chronic viral hepatitis (HR: 0.852, 95% CI: 0.596–1.219). Conclusions: There was no statistically significant difference in survival outcomes between atezolizumab plus bevacizumab and durvalumab plus tremelimumab in patients with decompensated advanced HCC. These results support current real-world practice in which both regimens may be considered viable first-line treatment options in this high-risk population with liver decompensation.