Phase II study of Mitonafide in advanced and relapsed colorectal cancer.

Background: This study investigated the antitumoral activity in colorectal cancer and toxicity of a 5-day continuous infusion of a new cytostatic agent, Mitonafide, that had previously shown to be neurotoxic when administered as a short daily x 5 days infusion.

Patients And Methods: Seventeen chemotherapy-naive patients with advanced or relapsed colorectal cancer and measurable disease entered the study. All but one received a 120-hour (5-day) continuous infusion of Mitonafide at a starting dose of 200 mg/m2/day every 3 weeks. Toxicity evaluation was performed after each course and response assessment every 2 courses using the standard World Health Organization (WHO) criteria completed by the "Mini-mental state" test for cognitive status examination.

Results: Sixteen patients received a total of 41 courses of Mitonafide which resulted to be severely myelotoxic. In total, 13/16 patients had WHO grade 3-4 neutropenia, 7 of them with infection, and the treatment had to be stopped in 3 patients after only 1 course due to excessive toxicity. No central nervous system toxicity was observed. No objective responses were evidenced.

Conclusions: At the dose and schedule of administration used, Mitonafide is not active in colorectal cancer and induces severe myelotoxicity thus not deserving further studies in this indication.