Phase I evaluation of carboplatin by use of a dosing strategy based on a targeted area under the platinum concentration-versus-time curve and individual glomerular filtration rate in cats with tumors

Objective—To determine whether a carboplatin dose calculation that is based on a targeted area under the concentration-versus-time curve (AUCTarget) and individual glomerular filtration rate (GFR) accurately predicts carboplatin-associated myelotoxicoses in tumor-bearing cats, and to determine the maximum tolerated AUCTarget. Animals—32 cats with tumors. Procedures—In each cat, plasma clearance of technetium Tc 99m-labeled diethylenetriaminepentaacetic acid was measured to assess GFR. Carboplatin was administered IV. The dose was calculated by use of an equation as follows: Dose = AUCTarget × 2.6 × GFR × body weight. Initial AUCTarget was 2.0 min·mg·mL−1 and was increased in increments of 0.50 min·mg·mL−1 in cohorts of 3 cats. To assess myelotoxic effects, CBCs were performed weekly for ≥ 4 weeks. Following identification of the maximum tolerated AUCTarget, additional cats were treated at that AUCTarget and plasma platinum concentrations were measured in 6 cats. Results—The AUCTarget values ranged from 2....