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.