Second-line treatment patterns and outcomes in advanced HCC after progression on atezolizumab/bevacizumab

Background & Aims: Atezolizumab/bevacizumab (A/B) is now a standard first-line treatment for advanced hepatocellular carcinoma (HCC), but the optimal second-line regimen is not known. We evaluated real-world treatment patterns and outcomes to investigate factors associated with post-progression survival (PPS). Methods: In this multicenter, international, retrospective study, we examined clinical characteristics and outcomes of patients with advanced HCC who progressed on first-line A/B. The primary outcome of PPS was defined as time from first radiographic progression on A/B to death. Results: A total of 406 patients alive after progression on first-line A/B were included in the final analysis, of whom 45.3% (n = 184) received best supportive treatment (BST) and 54.7% (n = 222) continued active systemic treatment. In the second line, 155 patients were treated with tyrosine kinase inhibitors (TKIs), 45 with immune checkpoint inhibitor (IO)-based regimens, and 3 had missing data. Median PPS of the whole cohort (mPPS) was 6.0 months (95% CI 5.2-7.2). On multivariate Cox regression analysis, absence of portal vein tumor thrombus, ECOG <2, and continued active treatment were predictors of better PPS. mPPS was significantly longer for patients who continued active treatment vs. BST (9.7 vs. 2.6 months; HR 0.41, p <0.001). In the second-line setting, patients treated with TKIs had a numerically shorter mPPS compared to those treated with IO (8.4 vs. 14.9 months; HR 1.37, p = 0.256). Conclusions: Continuation of active therapy after A/B progression was independently associated with better survival even after adjusting for baseline disease characteristics. mPPS with IO-based therapy exceeded a year, suggesting that IO continuation post-progression may retain benefit. The precise sequencing of TKI and IO regimens warrants further investigation. Impact and implications: There is currently a lack of level 1 data on second-line treatment options for patients with advanced hepatocellular carcinoma who progress after frontline atezolizumab plus bevacizumab, as all second-line approvals were established during the frontline sorafenib era. Our study aims to fill in some of the knowledge gap by investigating real-world patient outcomes in the second-line treatment setting. Findings from this study show that patients who continued active treatment had improved post-progression survival compared to those who received best supportive care, and medication regimens incorporating tyrosine kinase inhibitors as well as immunotherapy agents were active. These results can help inform clinicians of possible treatment options for patients who progress after frontline atezolizumab plus bevacizumab while we await maturing data from randomized-controlled trials.