Background: SOR is standard first-line systemic treatment for HCC unsuitable for locoregional therapy. RESORCE showed that REG improves overall survival (OS) in patients who progressed during SOR treatment (HR 0.63, 95% CI 0.50, 0.79; P < 0.001). This exploratory analysis describes outcomes for the sequence of SOR followed by REG. Methods: 573 patients were randomized 2:1 to receive REG 160 mg/day (d), 3 wks on/1 wk off or PBO. Data on prior SOR treatment and radiologic progression were prospectively collected. Efficacy and safety were evaluated by the last SOR dose. Time from the start of SOR to death was assessed. Results: Baseline characteristics were balanced. Times from the start of SOR to progression on SOR and times from progression on SOR to start of study drug were similar (Table). When analyzed based on last SOR dose 800 mg/d vs < 800 mg/d, rates of all grade treatment-emergent adverse events (TEAEs) on study were similar (REG: 100% vs 100%; PBO: 92% vs 93%). TEAE grades 3/4/5 by last SOR dose 800 mg/d vs < 800 mg/d were 52/11/15% vs 61/10/12%, respectively, with REG and 30/8/24% vs 32/7/14% with PBO. HRs (95% CI) REG/PBO for OS by last SOR dose were similar: 0.67 (0.51, 0.87) for 800 mg/d and 0.68 (0.48, 0.97) for < 800 mg/d. Median OS (95% CI) from the start of SOR was 26.0 months (22.6, 28.1) for REG and 19.2 months (16.3, 22.8) for PBO. Clinical trial information: NCT01774344Conclusions: This exploratory subgroup analysis by prior SOR dose demonstrates a consistent survival benefit for REG. In addition, the safety profile of REG was not remarkably different when analyzed by the last SOR dose.