PP0819 HEPATITIS C TREATMENT IMPROVES ONCOLOGIC OUTCOMES IN PATIENTS RECEIVING ATEZOLIZUMAB PLUS BEVACIZUMAB

Introduction: Hepatitis C virus (HCV) infection is a key driver of hepatocellular carcinoma (HCC) development and progression. However, the impact of HCV eradication in patients undergoing systemic therapy remains poorly understood. Aims & Methods: This study aimed to assess the safety and efficacy of direct- acting antiviral (DAA) therapy in patients receiving Atezolizumab plus Bevacizumab (AtezoBeva). This multicenter study retrospectively enrolled consecutive patients with HCV-related unresectable or advanced HCC undergoing AtezoBeva therapy between 2021 and 2024. Patients were stratified into three groups based on their HCV treatment status: group A (n=22), who received concurrent DAA therapy with AtezoBeva; group B (n=95), who had completed DAA therapy at least six months before initiating AtezoBeva; and group C (n=22), with active HCV infection. The impact of DAA treatment on overall survival (OS), time to progression (TTP), progression-free survival (PFS), time to decompensation (TTD), and decompensation-free survival (DFS) was evaluated. Additionally, the incidence of treatment-related adverse events (trAEs) was recorded. Results: Group A demonstrated a significantly prolonged median OS (42.8 months [95%CI: 33.3–NA]) compared to Group B (26.8 months [95%CI: 17.1–NA]; p=0.03) and group C (19.7 months [95%CI: 14.7–NA]; p=0.01). TTP was longer in group A (40.6 months [95%CI: 17.68–NA]) than in group C (14.6 months [95%CI: 5.06–NA]; p=0.02), whereas no significant difference was observed between group A and group B (20 months [95%CI: 12.29–NA]). Median PFS was markedly extended in group A (40.6 months [95%CI: 22.47–NA]) compared to group B (15 months [95%CI: 11.96–23.4]; p=0.009) and group C (13.3 months [95%CI: 5.06–NA]; p=0.002). Moreover, group A exhibited a higher disease control rate than the other groups. In the multivariate time-dependent analysis, achieving sustained virologic response (SVR) during AtezoBeva therapy was independently associated with a reduced risk of mortality (HR 0.29 [95%CI: 0.12–0.69]; p=0.005) and disease progression (HR 0.1 [95%CI: 0.05–0.72]; p=0.02). Notably, post-DAA decompensation rates were significantly lower in group A (4.5%) compared to groups B (26.3%) and C (36.4%), translating into a superior DFS. The incidence of grade ≥3 treatment-related AEs was comparable across groups. Conclusion: Achieving SVR during AtezoBeva therapy significantly enhances oncological outcomes in patients with unresectable or advanced HCC. These findings highlight the potential for an integrated therapeutic approach to optimize systemic treatment efficacy, particularly in patients eligible for conversion strategies.