Evaluation of vindesine and MER in colorectal cancer

Vindesine, a derivative of vinblastine, was administered to 39 patients with advanced colorectal cancer refractory to 5-fluorouracil alone or in combination with other chemotherapeutic agents. The initial dose of vindesine was 4 mg/m2 administered intravenously (IV) over 30 minutes every two weeks. Tumor regression of more than 50% was seen in 2 and stable disease in 13 of 33 patients evaluable for response. Prior treatment with vincristine did not seem to influence response to vindesine. The median survival time was four months. The major toxic effect of vindesine was peripheral neuropathy, which occurred in 35% of patients who received two or more courses of treatment. Methanol extract residue of BCG (MER) was administered IV to 20 of 39 patients receiving vindesine without randomization in order to evaluate toxicities associated with IV MER. The most common toxic reactions to MER were fever and chills, while malaise and headaches were less common. Transient respiratory distress associated with appearance of reticulonodular pulmonary infiltrates occurred in 1 patient. Thus, MER at a dose of less than 1 mg/m2 did not seem to significantly influence the response rate to vindesine or the survival of patients. However, it appeared to ameliorate the myelosuppression caused by vindesine.