Phase III study of capecitabine plus oxaliplatin compared with fluorouracil and leucovorin plus oxaliplatin in metastatic colorectal cancer: a final report of the AIO Colorectal Study Group.

Purpose: To compare the use of capecitabine plus oxaliplatin (CAPOX) with infusional fluorouracil (FU)/folinic acid plus oxaliplatin (FUFOX) as first-line therapy for patients with metastatic colorectal cancer (MCRC).

Patients And Methods: A total of 474 patients with MCRC received either CAPOX (capecitabine 1,000 mg/m2 bid, days 1 to 14 plus oxaliplatin 70 mg/m2 days 1 and 8, repeated every 22 days) ) or FUFOX (oxaliplatin 50 mg/m2 followed by leucovorin 500 mg/m2 plus FU 2,000 mg/m2 as a 22-hour infusion days 1, 8, 15, and 22, repeated every 36 days). The primary end point was progression-free survival (PFS). Secondary end points were response rate (RR), overall survival (OS), time to treatment failure, and toxicity. The study was designed to determine noninferiority for the CAPOX regimen.

Results: Median PFS was 7.1 months in the CAPOX arm and 8.0 months in the FUFOX arm (hazard ratio [HR], 1.17; 95% CI, 0.96 to 1.43; P = .117). Median OS was 16.8 months (CAPOX) and 18.8 months (FUFOX; HR, 1.12; 95% CI, 0.92 to 1.38; P = .26). Overall RRs were 48% for CAPOX (95% CI, 41% to 54%) and 54% for FUFOX (95% CI, 47% to 60%). Both regimens were generally well tolerated, although there was a significantly higher incidence of grade 2/3 hand-foot syndrome (HFS) in the CAPOX arm (P = .028).

Conclusion: CAPOX resulted in a slightly inferior efficacy than FUFOX. With respect to PFS, the best estimate of the HR of 1.17 was within the prespecified equivalence range. However, a relevant inferiority cannot be excluded. Both regimens were generally well tolerated but there was a significantly higher rate of grade 2/3 HFS in the CAPOX arm.