Metro-FOLFIRI as first line chemotherapy in metastatic colorectal cancer (MCRC). Preliminary report of a phase II trial

3722 Background: FOLFIRI regimen is standard therapy in MCRC. Angiogenesis is a critical step in the metastatic process of colorectal cancer. New agents with antiangiogenic effect showed to be active in MCRC. In preclinical studies irinotecan demonstrated to have at metronomic dose (1/6 standard dose) antiangiogenic activity. For these reasons we carried out this pilot study in order to evaluate the safety and the activity of metronomic FOLFIRI regimen as first line chemotherapy in inoperable MCRC. Methods: From 10/03 to 10/04 we treated 26 pts (14M 12F), median age 66 years (range 41–77) with this mixed FOLFIRI schedule: CPT-11 10 mg/mq days 1, 7, 10 and CPT-11 150 mg/mq day 2, Folinic Acid 100 mg/mq days 2 and 3, 5-FU 400 mg/mq bolus days 2 and 3 and 5-FU 600 mg/mq 44 hours c.i. days 2 and 3 every two weeks for a maximum of 12 cycles. Results: All pts are evaluable for toxicity and 22 for activity. The chemotherapy was well tolerated; no toxic deaths occurred, no therapy ended for toxicity. 3 pts had 25% reduction dose for diarrhea G4 after the first cycle. The main toxicities recorded on a total of 173 cycles (cy) delivered were: diarrhea G4 1.7% and G3 2.3% of the cy. Neutropenia G3 5.8% and vomiting G3 0.5% of the cy. Anemia G2 was recorded in 7 pts. All pts suffered from partial alopecia and half of the pts from mild oral mucositis. As regard activity we registered 3 CR (13.6%), 9 PR (40.9%), 7 SD (31.8%) and 3 PD (13.6%). Before start therapy and after 4th, 8th and 12th cycle we collected blood samples of the pts in order to evaluate sVEGF modifications in relation to objective response. These data will be presented. Conclusions: Metro-FOLFIRI regimen appears to be safe and active in MCRC. No significant financial relationships to disclose.