Background: 5-fluorouracil (5-FU), irinotecan, and oxaliplatin are the most active drugs in advanced colorectal cancer (CRC), and survival is improved with patient exposure to all of them. The efficacy and safety of an alternating schedule of continuous-infusion 5-FU with leucovorin (LV) plus oxaliplatin (ie, FOLFOX regimen) or irinotecan (ie, FOLFIRI regimen) was assessed in the first-line setting.
Patients and methods: Seventy-nine patients with previously untreated, unresectable CRC were included. Treatment consisted of 5-FU/LV (de Gramont schedule) plus oxaliplatin (85 mg/m2) alternated biweekly with the same 5-FU/LV regimen plus irinotecan (180 mg/m2). Treatment was maintained until tumor progression or unacceptable toxicity was noted.
Results: Median age was 62 years. Performance status was 0/1 in 91% of patients, 63% had 1 organ involved, and 80% had liver metastases. A median of 6 courses per patient (range, 1-9) and a total of 952 infusions were given. The most frequent grade 3/4 toxic events were neutropenia (32%), diarrhea (26%), and asthenia (7%). Grade 1/2 neurotoxicity was seen in 59% of cases, but no grade 3/4 neurotoxicity was observed. There were no toxic deaths. An objective response rate of 54% (4 complete responses plus 39 partial responses) was attained. Median time to progression and overall survival were 13 months and 18 months, respectively.
Conclusion: This alternating schedule is active, with efficacy results similar to those seen with sequential protocols, the advantages of less toxicity, and 100% patient exposure to irinotecan and oxaliplatin.