3758 Background: Preclinical data have shown a synergistic effect when MMC and CPT-11 are combined. In addition, this combination proved to be effective and well-tolerated in patients with fluoropyrimidine-resistant metastasic colorectal cancer Methods: To evaluate the safety and efficacy of MMC 5 mg/m2 day 1 plus CPT-11 200 mg/m2 on day 1, every three weeks, in a retrospective series of heavily pretreated metastasic CCR patients with good performance status (ECOG 1–2). Results: From September 2002 to October 2003, 20 pts (M/F: 13/7; ECOG 2: 50%; Median age: 55) were included. Sites of metastasic disease included peritoneal carcinomatosis (65%), lung (35%), liver (65%) and bone (15%). 12 pts (60 %) had received at least 3 lines of therapy. Prior chemotherapy included 5-fluorouracil (90%), oxaliplatin (100%) irinotecan (65%), capecitabine (85%) and raltitrexed (60%). Previous FOLFOX, FOLFIRI, FOLFOXIRI or XELOX had been administered in 50%, 15%, 25% and 35% of the patients, respectively. 4 pts (20%) achieved a partial response, stable disease was found in 10 pts (50%), while 6 pts (30%) progressed while on-therapy.After a median follow-up of 7.5 months (1.7–15.2), median progression-free survival was 4.07 months (95% CI; 2.04–6.09) and median overall survival was 4.4 months (95% CI;1.3–7.5). Grade 3–4 toxicities includad leucopenia (10%), neutropenia (10%), anemia (30%), asthenia (15%) and diarrhea (20%). Conclusions: The combination of MMC and CPT-11 shows modest activity in this subgroup of heavily pretreated CCR patients No significant financial relationships to disclose.