Impact of Temporary Atezolizumab and Bevacizumab Interruption on Survival in Advanced HCC: An IMbrave150 Analysis

Background Atezolizumab (Atez) combined with bevacizumab (Bev) is the recommended first-line treatment for unresectable hepatocellular carcinoma (HCC). This study investigated the association of temporary Atez and Bev interruptions with clinical outcomes using IMbrave150 trial data. Patients and Methods Patient-level data from the phase 3 IMbrave150 (NCT03434379) trial were analyzed. Time-dependent Cox regression models assessed associations between temporary interruptions and overall survival (OS) and progression-free survival (PFS), adjusting for treatment duration and drug discontinuation. Subgroup analyses were stratified by event timing and treatment duration (<12 vs. ≥12 months). Results Among 251 patients treated with Atez/Bev, 79 (31.5%) experienced Atez interruptions and 86 (34.3%) had Bev interruptions. Interruptions were not significantly associated with OS (HR = 1.57, 95% CI: 0.90–2.73 for Atez, HR = 0.50, 95% CI: 0.16–1.53 for Bev). However, both were significantly associated with improved PFS (HR = 0.56, 95% CI: 0.34–0.92 for Atez and HR = 0.61, 95% CI: 0.39–0.94 for Bev). Subgroup analyses showed that positive association of PFS and interruptions was primarily observed in patients with events or treatment duration <12 months. Early (within 6 months) and late interruptions (after 6 months) showed trends toward longer PFS but were not statistically significant (HR = 0.56, 95% CI: 0.27–1.15 and HR = 0.57, 95% CI: 0.29–1.09 for Atez, HR = 0.61, 95% CI: 0.37–1.02 and HR = 0.60, 95% CI: 0.29–1.27 for Bev). Conclusion In this exploratory analysis, temporary interruptions of Atez or Bev were not associated with worse survival outcomes in patients with unresectable HCC. Prospective studies are needed to validate these findings.