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.