This study is being conducted to determine whether administration of a single IV dose of palifermin 3 days before initiation of chemotherapy and 3 days before each subsequent treatment cycle would reduce the incidence of oral mucositis and to evaluate the safety profile in the subject population. This study will evaluate the efficacy of palifermin in reducing the incidence of grade ≥ 2 OM in subjects with stage 2B or stage 3 locally advanced, colon cancer undergoing adjuvant chemotherapy with 5-FU and leucovorin in cycle 1. This study will also assess the safety and tolerability of palifermin administered as a single IV dose before each cycle of 5-FU and leucovorin, evaluate the effect of palifermin on patient-reported mouth and throat soreness, the incidence of grade ≥ 2 oral mucositis in cycle 2, the duration of grade ≥ 2 oral mucositis, 5-FU dose reductions/delays and the long-term effects of palifermin on disease outcome and survival.