Phase II evaluation of vindesine in the treatment of colorectal and esophageal tumors

A phase II study of vindesine was carried out in 33 patients with colorectal cancer and nine patients with esophageal cancer. With the exception of six previously untreated patients with esophageal cancer, all others were refractory to 5-FU-containing regimens, which included vincristine in ten patients. The initial dose of vindesine was 4 mg/m² administered intravenously over 30 min every 2 weeks. Tumor regression >50% was seen in three patients (two colorectal and one esophageal) and an additional eight patients (six colorectal and two esophageal) achieved minor responses. Prior treatment with vincristine did not seem to influence response to vindensine. In general, the treatment with vindesine was well tolerated. The hematologic toxicity was acceptable and manifested mainly as moderate and transient neutropenia. The major nonhematologic toxicity was peripheral neuropathy, which became limiting. It occurred in 33% of patients who received two or more courses of vindesine. Because of the apparent antitumor activity and doselimiting neurotoxicity of vindesine in this study, further investigations of this compound should be conducted in combination chemotherapy programs for patients with metastatic gastrointestinal cancers.