Background: To evaluate the efficacy and tolerance of combined raltitrexed and oxaliplatin in patients with advanced colorectal cancer pretreated with fluoropyrimidine leucovorin-based chemotherapy.
Patients and methods: Thirty-six patients with metastatic colorectal cancer, who progressed while receiving or within six months after withholding palliative chemotherapy with fluoropyrimidines leucovorin +/- irinotecan, participated in this study. Treatment consisted of oxaliplatin 130 mg/m2 and raltitrexed 3.0 mg/m2 both given on day 1 every three weeks for a total of eight courses unless prior evidence of progressive disease.
Results: The overall objective response rate was 33.3% for all 36 evaluable patients (95% confidence interval (CI): 18.6%-51%). Seventeen additional patients (47.2%) had stable disease, and only seven (19.5%) progressed. The median progression-free survival was 6.5 months (range 1.2-14.0). After a median follow-up time of 12 months, 23 patients (63.8%) are still alive. The tolerance of treatment was acceptable with only 8 of 36 patients (22%) experiencing grade 3 or 4 neutropenia. Grade 3 non-haematological adverse reactions included peripheral sensory neuropathy in three, asthenia in one, diarrhea in two, and clinically insignificant increase in serum transaminases in two patients, respectively.
Conclusions: Our data suggest that the combination of oxaliplatin and raltitrexed has substantial antitumour activity in patients with progressive fluoropyrimidine leucovorin + irinotecan pretreated colorectal cancer. Because of its favorable toxicity profile and convenient three-weekly outpatient administration schedule, further evaluation of this regimen seems warranted.