Atezolizumab plus bevacizumab treatment for unresectable hepatocellular carcinoma: Early clinical experience

Background: Although atezolizumab plus bevacizumab (Atez/bev) treatment has been developed for unresectable hepatocellular carcinoma (u-HCC), changes in hepatic function during therapy have yet to be reported. Aim: This retrospective clinical study aimed to elucidate early responses to Atez/Bev. Methods: From September 2020 to April 2021, 171 u-HCC patients undergoing Atez/Bev treatment were enrolled (BCLC stage A:B:C:D = 5:68:96:2). Of those, 75 had no prior history of systemic treatment. Relative changes in hepatic function and therapeutic response were assessed using albumin-bilirubin (ALBI) score and Response Evaluation Criteria in Solid Tumors (RECIST), ver. 1.1, respectively. Results: In initial imaging examination findings, objective response rates for early tumor shrinkage and disease control after 6 weeks (ORR-6W/DCR-6W) were 10.6%/79.6%. Similar response results were observed in patients with and without a past history of systemic treatment (ORR-6W/DCR-6W = 9.7%/77.8% and 12.2%/82.9%), as well as patients in whom Atez/Bev was used as post-progression treatment following lenvatinib (ORR-6W/DCR-6W = 7.7%/79.5%), for which no known effective post-progression treatment has been established. In 111 patients who underwent a 6-week observation period, ALBI score was significantly worsened at 3 weeks after introducing Atez/Bev (−2.525 ± 0.419 vs −2.323 ± 0.445, p <.001), but then recovered at 6-weeks (−2.403 ± 0.452) as compared to 3-weeks (p =.001). During the observation period, the most common adverse events were appetite loss (all grades) (12.3%), general fatigue/hypertension (all grades) (11.1%, respectively), and urine protein (all grades) (10.5%). Conclusion: Atez/Bev might have therapeutic potential not only as first but also later-line treatment of existing molecular target agents. In addition, this drug combination may have less influence on hepatic function during the early period, as the present patients showed a good initial therapeutic response.