Objective response (OR) by mRECIST to predict overall survival (OS) in patients with hepatocellular carcinoma (HCC) treated with sorafenib in the SILIUS trial.

534 Background: In SILIUS (NCT01214343) trial, combination of sorafenib and hepatic arterial infusion chemotherapy did not significantly improve OS in patients with advanced HCC compared with sorafenib alone (Kudo M, et al. Lancet Gastroenterol Hepatol 2018). In this study, we explored the relationship between OR and OS in the sorafenib group in the SILIUS trial. Methods: Association between OR and OS in patients treated with sorafenib ( n = 103) were analyzed. The median OS of responders was compared with that of non-responders by using Mantel-Byar test to exclude guarantee-time bias. Landmark analyses were performed, as sensitivity analyses, and the effect on OS was evaluated by Cox regression analysis with OR as a time-dependent covariate, with other prognostic factors. Results: OS of responders ( n = 18) was significantly better than that of non-responders ( n = 78) ( p < 0.0001), where median OS was 27.2 (95% CI, 16.0–not reached) months for responders and 8.9 (95% CI, 6.5–12.6) months for non-responders. HRs from landmark analyses at 4, 6, and 8 months were 0.45 ( p = 0.0330), 0.37 ( p = 0.0053), and 0.36 ( p = 0.0083), respectively. OR by sorafenib was an independent predictor of OS based on unstratified Cox regression analyses. Conclusions: In the SILIUS trial, OR achieved by sorafenib per mRECIST is an independent predictor for OS in patients with HCC. [Table: see text]