Treatment response to durvalumab plus tremelimumab after progression with previous immune checkpoint inhibitor in unresectable hepatocellular carcinoma.

Although immune checkpoint inhibitors (ICI) are used for unresectable hepatocellular carcinoma (HCC), it is unclear whether sequential ICI treatment-durvalumab plus tremelimumab (DT) after progression on atezolizumab plus bevacizumab (AB)-is effective for HCC. In this nationwide multicenter study, we aimed to investigate the effect of DT treatment based on the timing of treatment. A total of 85 patients receiving DT treatment were enrolled. The primary endpoint is treatment response at week 8 among patients receiving first-line DT treatment, those receiving second-line or later treatment without prior AB therapy, and those receiving second-line or later treatment with prior AB therapy. Objective response rates (ORRs) in patients with first-line treatment, second-line treatment without AB, and second-line treatment with prior AB were 44%, 54%, and 5%, respectively (p < 0.001). Similarly, disease control rates (DCRs) were 69%, 91%, and 26%, respectively (p < 0.001). ORR and DCR were significantly lower in patients with prior AB treatment. Progression free survival (PFS) was significantly shortened in patients receiving second-line therapy following prior AB treatment and an adjusted hazard ratio (95% confidence interval) in those patients for PFS, using first-line therapy as a reference, was 2.35 (1.1-5.1, p = 0.03). In conclusion, the impact of DT sequencing following AB treatment was limited. However, even after second-line treatment, the treatment effect can be equivalent to that of first-line treatment in cases with no history of AB treatment. Thus, prior treatment history should be taken into account when initiating DT treatment.