A randomized phase II study of modified OPTIMOX1 or FOLFOX in advanced colorectal cancer.

Abstract

519 Background: A combination of leucovorin (LV) and fluorouracil (FU) with oxaliplatin (FOLFOX) is a standard first-line regimen for advanced or unresectable colorectal cancer. Sensory neurotoxicity is its dose-limiting toxicity, but the OPTIMOX1 (stop and go) approach offers a reasonable strategy. This study evaluates a new strategy of intermittent oxaliplatin treatment that is based on FOLFOX4 or modified FOLFOX6 (+/− bevacizumab), a simplified leucovorin and fluorouracil regimen with normal-dose oxaliplatin. Methods: Previously untreated patients were randomly assigned to either FOLFOX administered every 2 weeks until progression (arm FOL) or FOLFOX for six cycles, maintenance without oxaliplatin for six cycles, and continued every six cycles until progression (arm OPT). Results: Sixty patients (arm FOL [n=35], arm OPT [n=33]) were enrolled. The median number of treatment cycles was 10 (range, 3-28) in arm FOL and 12.5 (range, 1-32) in arm OPT. Cumulative dose of oxaliplatin was 850 mg/m2 in arm FOL and 552.5 mg/m2 in arm OPT. Median progression-free survival was 8.5 months in patients allocated to arm FOL compared with 15 months in patients allocated to arm OPT. Response rates evaluated by RECIST criteria were 50% with arm FOL and 64% with arm OPT. National Cancer Institute Common Toxicity Criteria grade 3 toxicity was observed in 37.1% of the patients in arm FOL and 24.0% of patients in arm OPT. Grade 3 sensory neuropathy was observed in 22.8% of the patients in arm FOL and 6% of patients in arm OPT. Conclusions: Our modified OPTIMOX1 regimen may be effective and safe treatment to prevent oxaliplatin-induced neuropathy in advanced or unresectable colorectal cancer patients. No significant financial relationships to disclose.