Evaluation of Response to Atezolizumab Plus Bevacizumab in Patients with Advanced Hepatocellular Carcinoma Using the Combination of Response Evaluation Criteria in Solid Tumors and Alpha-Fetoprotein

SIMPLE SUMMARY: Hepatocellular carcinoma (HCC) is reportedly the fifth most common malignancy in the world. Atezolizumab plus bevacizumab combination therapy (Atezo + Beva) was approved in 2020 as the first immune-combined therapy and the standard of care for first-line systemic treatment of unresectable HCC. Alpha-fetoprotein (AFP) is the most widely used serum biomarker in HCC. Although some studies have shown the benefit and safety of Atezo + Beva, there are no reports on when to switch from Atezo + Beva to the next treatment, and this is not yet clear. This study investigated the relationship between radiological response and prognosis in patients assessed as having stable disease (SD) in whom it is necessary to decide whether to continue Atezo + Beva. The results showed that a decreased AFP level may reflect early efficacy, and AFP trends could help determine whether to continue Atezo + Beva in patients assessed as having SD. ABSTRACT: Atezolizumab plus bevacizumab combination therapy (Atezo + Beva) is currently positioned as the first-line therapy for unresectable hepatocellular carcinoma (u-HCC). It may be difficult to decide whether to continue this treatment if radiological response is assessed as stable disease (SD). Therefore, the relationship between radiological response and prognosis was analyzed. A total of 109 patients with u-HCC and Child–Pugh Score of 5–7 received this treatment. Radiological response was assessed using Response Evaluation Criteria in Solid Tumors (RECIST) and modified RECIST at the first and second evaluations. Of SD patients (n = 71) at the first RECIST evaluation, partial response, SD, and progressive disease (PD) were seen in 10, 55, and 6 patients, respectively, at the second evaluation. On multivariate analysis, in patients with SD at the first RECIST evaluation, a 25% or greater increase in the alpha-fetoprotein (AFP) value from initiation of treatment (odds ratio, 7.38; p = 0.037) was the independent factor for PD at the second evaluation. In patients with SD (n = 59) at the second RECIST evaluation, decreased AFP from initiation of treatment (hazard ratio, 0.46; p = 0.022) was the independent factor related to progression-free survival on multivariate analysis. AFP trends could help decide the Atezo + Beva treatment strategy.