Objective Response by mRECIST Is an Independent Prognostic Factor for Overall Survival in Hepatocellular Carcinoma Treated with Sorafenib in the SILIUS Trial

Objective: In SILIUS (NCT01214343), combination of sorafenib and hepatic arterial infusion chemotherapy did not significantly improve overall survival (OS) in patients with advanced hepatocellular carcinoma (HCC) compared with sorafenib alone. In this study, we explored the relationship between objective response by mRECIST and OS in the sorafenib group, in the combination group, and in all patients in the SILIUS trial. Methods: Association between objective response and OS in patients treated with sorafenib (n = 103) or combination (n = 102) and all patients (n = 205) were analyzed. The median OS of responders was compared with that of non-responders. Landmark analyses were performed according to objective response at several fixed time points, as sensitivity analyses, and the effect on OS was evaluated by Cox regression analysis with objective response as a time-dependent covariate, with other prognostic factors. Results: In the sorafenib group, 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. Objective response was an independent predictor of OS based on unstratified Cox regression analyses. In the all patients and the combination group, similar results were obtained. Conclusions: In the SILIUS trial, objective response by sorafenib assessed by mRECIST is an independent prognostic factor for OS in patients with HCC.