Animal models for the comparative assessment of neurotoxicity following repeated administration of vinca alkaloids.

Neurotoxicity is the major side effect occurring during the clinical use of vincristine (VCR). Animal models predictive of potential neurotoxicity would be very useful in the preclinical development of new vinca compounds. To simulate conditions in which neurotoxicity is produced during the clinical use of VCR, experimental animals (except the guinea pig) were given the test compounds by the iv route over a prolonged time period. Doses were selected based on the production of leukopenia. Vindesine (VDS), a chemically modified vinblastine (VBL) product, was compared with VCR and VBL in animal studies. Definite neurotoxic manifestations developed when VCR was given to chickens, cats, and monkeys. The administration of VDS or VBL did not produce neurotoxic signs in these species. The mouse, rat, dog, and guinea pig were not found to be useful models. Thus, it would appear the chicken, cat, and monkey would be appropriate animal models for the preclinical testing of new vinca compounds.