EXPERT study: Randomized phase III trial of radical surgery and postoperative mFOLFOX6 versus perioperative mFOLFOX6 plus cetuximab in patients with KRAS wild-type resectable colorectal liver metastases (CLMs).
652 Background: Up-front radical surgery and adjuvant chemotherapy were regarded as one of the standard-of-care (SOC) in patients with resectablecolorectal liver metastases (CLMs), while perioperative chemotherapy plus surgery is also accepted. We conducted a multicenter randomized phase III trial to compare radical surgery and post-operative mFOLFOX6 with peri-operative mFOLFOX6 plus cetuximab in patients with KRAS wild-type resectable CLMs. Methods: Patients who had KRAS wild-type resectable CLMs having one to eight liver nodules without extrahepatic disease, were randomly assigned to groups: Group A (reference), hepatectomy and 12 cycles of post-operative mFOLFOX6: Group B (experimental), six cycles of preoperative mFOLFOX6 plus cetuximab (loading dose with 400mg/m2and thereafter 250mg/m2weekly), hepatectomy and six cycles of postoperative mFOLFOX6 plus cetuximab. Primary endpoint was progression-free survival (PFS). We hypothesized that 3-year PFS in Group B would be 25% with the hazard ratio (HR) being 0.75. Considering 3 year follow-up period with 5% of two-sided alpha error and 80% of power, target number were set as 500 (250 each). Study was registered in the University Hospital Medical Information Network (UMIN000007787). Results: This study was initiated since June 2012. However, the enrollment was terminated according to the recommendation from the monitoring committee on 2015 due to a slow accrual. A total of 77 patients (Group A 37 vs. Group B 40) were analyzed. Baseline characteristics were well-balanced between groups. Median numbers of liver mets were two each, ranging from one to eight. The HRs for PFS and overall survival (OS) showed no significant difference (PFS, HR = 1.18 [0.69-2.01], p = 0.54: OS, HR = 1.03 [0.46 – 2.29], p = 0.95). There were 3-year PFS of 35% in Group A vs. 30% in Group B, and 3-year OS: 86% vs. 74%, respectively. Conclusions: No additional survival benefits adding on peri-operative cetuximab were indicated, of which findings is consistent with the previous clinical studies, although there were small number of enrolled patients. Clinical trial information: UMIN000007787.