363 Background: Irinotecan (CPT-11) has demonstrated antitumor activity against metastatic colorectal cancer used alone or with 5-fluorouracil (5FU)/leucovorin (LV). Two arms with CPT-11, 5FU, and LV (FOLFIRI) +/- cetuximab (Cmab) were originally included in N0147. However, after CALGB 89803 (J Clin Oncol. 25:3456, 2007), PETACC-3 (J Clin Oncol. 27:3117, 2009), and Accord02 (Ann Oncol. 20:674, 2009) showed no benefit to the three-drug combination in adjuvant therapy, the CPT-11 arms of N0147 were discontinued. We report the outcomes for patients given FOLFIRI +/- Cmab. Methods: Following a signed informed consent patients with resected stage III colon cancer were randomized to one of 6 arms including 12 biweekly cycles of CPT-11 180 mg/m2 d1 with LV 400 mg/m2, 5FU 400 mg/m2 bolus IV, then 46-hr IV 5FU 2,400 mg/m2 on d1-2 without (Arm B, FOLFIRI) or with Cmab (Arm E) 400 mg/m2 d1 cycle 1 then Cmab at 250 mg/m2 d1 and 8. Primary endpoint was 3-year disease-free survival (DFS). Secondary endpoints included overall survival (OS) and toxicity. Results: 156 patients (Arm B-111, Arm E-45) were enrolled; median follow-up on 81 patients in Arm B was 60.3 months and 58.2 months in Arm E for 41 patients. wtKRAS (vs mt) status was associated with improved DFS (HR=0.6 [95% CI 0.4-1.1], p = 0.09) and OS (HR 0.7 [95% CI 0.4-1.5], p = 0.38). The addition of Cmab improved DFS and OS in the overall group and within wtKRAS pts. Grade greater than III non-hematologic adverse effects were significantly increased in the Cmab arm (46% vs. 64%, p = 0.05). Conclusions: In this randomized phase III trial adjuvant FOLFIRI resulted in a 3-year DFS lower than that expected for FOLFOX. Trends for improved DFS and OS with the addition of Cmab were observed in patients with resected stage III colon cancer patients, regardless of KRAS status. Supported by NIH Grant CA25224, Bristol-Myers Squibb, ImClone, Sanofi-Aventis, and Pfizer. [Table: see text] [Table: see text]