A phase III trial comparing mFOLFOX6 to mFOLFOX6 plus bevacizumab in stage II or III carcinoma of the colon: Results of NSABP Protocol C-08

Abstract

LBA4 Background: The primary aim of this two-arm randomized prospective study was to determine whether mFOLFOX6 plus bevacizumab (mFF6+B) would prolong disease-free survival (DFS) compared to mFOLFOX6 (mFF6) alone. Methods: Between September 2004 and October 2006, 2,672 patients with follow-up (1,338 and 1,334 in respective arms) with stage II (24.9%) or III carcinoma of the colon were randomized to receive either mFF6 (oxaliplatin 85 mg/m 2 IV d1, leucovorin 400 mg/m 2 IV d1, 5-FU 400 mg/m 2 IV bolus d1, and 5-FU 2400 mg/ m 2 CI over 46 hrs (d1+2) q14d × 12 cycles) or mFF6+B (same mFF6 regimen + bevacizumab 5 mg/kg IV q 2 wks × 1 yr). The primary end point was DFS. Events were defined as first recurrence, second primary cancer, or death. Results: The median follow-up for patients still alive was 36 months. The hazard ratio (HR: FF6+B vs. mFF6) was 0.89; 95% CI (0.76=1.04); p=0.15. Data censored at intervals disclosed an initial benefit for bevacizumab that diminished over time: The smoothed estimate of the DFS HR over time indicated that bevacizumab significantly reduced the risk of a DFS event during the interval from 0.5 to 1.0 year. There was no evidence that patients receiving bevacizumab had a worse DFS compared to those receiving mFF6 alone following treatment. Conclusions: The addition of bevacizumab to mFF6 did not result in an overall statistically significant prolongation in DFS. There was a transient benefit in DFS during the one-year interval that bevacizumab was utilized. Consideration may be given to clinical trials assessing longer duration of bevacizumab administration. Supported by PHS grants U10CA-12027, -69974, -37377, and -69651 from the NCI and a grant from Genentech, Inc. [Table: see text] No significant financial relationships to disclose.