Bimonthly Chemotherapy with Oxaliplatin, Irinotecan, Infusional 5-Fluorouracil/Folinic Acid in Patients with Metastatic Colorectal Cancer Pretreated with Irinotecan- or Oxaliplatin-Based Chemotherapy

This study was conducted to assess the tolerability and efficacy of a ternary bimonthly irinotecan (CPT-11) - oxaliplatin (OHP) - infusional 5-fluorouracil (5-FU)/folinic acid (FA) combination in advanced colorectal cancer patients who had received prior CPT-11 and/or OHP-based chemotherapy regimen. Colorectal cancer patients were given bimonthly CPT-11 as a 90-min infusion, followed by OHP (85 mg/m(2)), FA (200 mg/m(2)) 2-h infusions and 5-FU (48-h infusion). CPT-11 and 5-FU doses were escalated as reported below. 26 patients were recruited. Fourteen patients had received a prior CPT-11-, 6 patients a prior OHP-based chemotherapy regimen and 6 patients both regimens. Three dose levels were investigated: CPT-11 100, 120 and 140 mg/m(2) and 5-FU 1500, 1800 and 2100 mg/m(2) in 6, 12 and 8 patients, respectively. All patients were evaluable for toxicity, 24 for antitumor activity. At all dose levels toxicity was acceptable. Grade 4 toxicity occurred in two patients only (neutropenia in one case and stomatitis in another one, 3.8%). Grade 3 toxicities included nausea and vomiting (34.6%), asthenia (26.9%), neurosensory toxicity (15.4%), neutropenia (3.8%) and diarrhea (3.8%). Hematological toxicity was infrequent and generally mild. At the third dose level, a higher, although not significantly different incidence of hematological and neurosensory toxicity (both occurring in 62.5% of cases, all grades) was observed compared to the other two, while nausea and vomiting were significantly less frequent (37.5% vs 100%). Overall, we observed 2 complete responses, 9 partial responses (OR 45.8%), 8 stable disease (33.3%), and 5 disease progression (20.8%). Median overall survival was 18 months and median time-to-progression 5.5 months. This combination showed moderate toxicity and promising antitumor activity in CPT-11 and/or OHP pretreated colorectal cancer patients. The second dose level using CPT-11 at 120 mg/m(2) and 5-FU at 1800 mg/m(2) is recommended for further phase 11 studies in this patient population.