ECOG phase II trials of MGBG, chlorozotocin, COM multidrug therapy in advanced measurable colorectal cancer

The Eastern Cooperative Oncology Group (ECOG) entered 326 patients with advanced measurable colorectal cancer into four phase II drug or drug combination trials. Previously treated and chemotherapy-naive patients were eligible. Chlorozotocin was administered to 83 patients (51 previously treated), methyl-glyoxal-bis-guanylhydrozone (MGBG) to 90 patients (58 previously treated), and two regimens of the three-drug combination of cyclophosphamide, vincristine, and methotrexate (COM) to 153 patients (120 previously treated). The multidrug regimen had been developed specifically for previously treated patients. In this trial, chemotherapy-naive patients were no more likely to respond than were members of the previously-treated group. Even among previously untreated patients, response rates did not exceed 10% in any of these phase II programs. They are not recommended for further trials in patients with colorectal cancers.