Baseline ALBI score and early variation of serum AFP predicts outcomes in patients with HCC treated by atezolizumab-bevacizumab

Background: The combination of atezolizumab and bevacizumab (AtezoBev) is the current first-line treatment for patients with hepatocellular carcinoma (HCC). Our aim was to evaluate the prognostic role of alpha-foetoprotein (AFP) early response and its combination with albumin-bilirubin (ALBI) in these patients. Methods: Patients with HCC under AtezoBev with AFP > 20 ng/ml were included in three centres. The optimal threshold of AFP variation after 3 weeks of treatment was identified for overall survival (OS) and radiological response (RR) using RECIST 1.1 and mRECIST and its ability to predict progression-free survival (PFS) and OS was tested using univariate and multivariate analysis in derivation and validation cohorts. Results: Seventy-five patients with AFP values >20 ng/ml were included. Fifty-eight patients were male with a median age of 63.5 years; 73% had cirrhosis and HCC stage was classified as BCLC B (18.7%) or C (81.3%). In the derivation cohort (n = 38), a decline in AFP ≥ 20% at 3 weeks (AFP early response) was associated with RR using mRECIST criteria (OR: 13.09 95% CI: 1.44-19.34 p = .02), PFS (HR: 0.42; 95% CI: 0.19-0.93, p = .03) and OS (HR: 0.35; 95% CI: 0.15-0.83, p = .01). AFP early response was confirmed as predictor of RR (p = .02 for mRECIST) and OS (p = .03) in the validation cohort (n= 37). In the whole cohort, the combination of ALBI and AFP early response was significantly associated with OS (p = .046) and PFS (p = .012) with a poor prognosis in patients belonging to the ALBI2-AFP non-responders class. Conclusion: AFP early response at 3 weeks predicts oncological outcomes in HCC patients treated with AtezoBev and combination with ALBI grade refines prognostic discrimination.