Background
Phase III, open-label RCT. 2559 patients with KRAS exon 2 WT resected stage III colon cancer. A large European trial testing whether cetuximab added to FOLFOX4 improves DFS in KRAS-selected adjuvant colon cancer. Conducted in parallel to N0147, providing independent confirmation in a European population.
Interventions and follow up
Arm A: FOLFOX4 × 12 cycles + cetuximab 400mg/m² IV loading then 250mg/m² IV weekly × 24 wk
Arm B: FOLFOX4 × 12 cycles alone
Primary endpoint: Disease-free survival (DFS)
mFollow up: 61.7 mo
Arm B: FOLFOX4 × 12 cycles alone
Primary endpoint: Disease-free survival (DFS)
mFollow up: 61.7 mo
Results
DFS (KRAS exon 2 WT): HR 0.89, 95% CI 0.76–1.04, P=.12 — not significant
DFS (all-RAS WT, exploratory): HR 0.78, P=.064 — not significant after correction
OS: HR 0.97 — not significant
DFS (KRAS mutant, exploratory): HR 1.28 — harm signal, not significant
DFS (all-RAS WT, exploratory): HR 0.78, P=.064 — not significant after correction
OS: HR 0.97 — not significant
DFS (KRAS mutant, exploratory): HR 1.28 — harm signal, not significant
Adverse events
Dermatologic/infusion: Acneiform rash grade ≥3 29.6% vs 0%; infusion reactions 2.2% vs 0%
GI/overall: Diarrhea grade ≥3 12.9% vs 8.6%; overall grade ≥3 74.0% vs 55.5%; treatment discontinuation due to AEs 23.3% vs 7.4%
GI/overall: Diarrhea grade ≥3 12.9% vs 8.6%; overall grade ≥3 74.0% vs 55.5%; treatment discontinuation due to AEs 23.3% vs 7.4%
Conclusions
Adding cetuximab to adjuvant FOLFOX4 did not improve DFS in KRAS WT or all-RAS WT stage III colon cancer, with a trend toward worse outcomes in KRAS mutant patients. PETACC-8 independently confirmed the negative finding of N0147, providing definitive evidence against EGFR inhibition in adjuvant CRC.
Key Limitations
Key Limitations: KRAS exon 2 WT was required but extended RAS testing was only performed retrospectively — the prospectively enrolled population included patients who would have NRAS or KRAS exon 3/4 mutations by modern standards. The all-RAS WT subgroup (retrospectively defined) showed HR 0.78, which generated discussion but was exploratory and underpowered for confirmatory conclusions. The high rate of cetuximab discontinuation (23%) limits interpretation of the cetuximab-specific contribution. The 1.28 harm signal in KRAS mutant patients, consistent with N0147, supports biomarker-directed harm.
Clinical Context
PETACC-8 (Europe) and N0147 (North America) are the definitive trials establishing that anti-EGFR monoclonal antibodies have no role in adjuvant colon cancer in either KRAS WT or RAS WT patients. Despite benefit in the metastatic setting, the adjuvant setting shows consistent failure and possible harm in RAS mutant patients. These trials are frequently cited alongside NSABP C-08 and AVANT in discussions of the challenge of translating metastatic CRC treatment advances to the adjuvant setting.
References
References: Taieb J et al, Lancet Oncol 2014