Cyclophosphamide, etoposide and hexamethylmelamine (CE-Hex) for 5-fluorouracil-resistant metastatic colon cancer: A phase II trial

There are limited treatment options for patients with metastatic colorectal cancer who have failed treatment with a 5-fluorouracil (5FU)-based chemotherapy regimen. Cyclophosphamide, etoposide and hexamethylmelamine have all been shown to have activity against colorectal cancer as single agents. In this study, we report the results of a phase II trial evaluating the response of patients with colorectal cancer who had previously progressed on a 5FU-based regimen to combination chemotherapy with cyclophosphamide (600 mg/M²), etoposide (60 mg/M²) and hexamethylmelamine (200 mg/M²/day x 14 d) (CE-Hex). Two of 16 patients evaluable for response achieved a partial response (12.5%) and 5 others had stabilization of previously progressive disease (overall response/stabilization rate of 43.8%). The median overall survival for responders was 12 months compared to 6 months for the entire patient population. Of 18 patients treated, only 3 patients experienced grade 3 toxicity. The most common toxicity was nausea and vomiting. There were no toxic deaths. CE-Hex has limited but definable activity in patients with metastatic colorectal cancer who have failed standard 5FU-based therapy.