• Open Access

Phase I Clinical Evaluation of Carboplatin in Tumor-Bearing Cats: A Veterinary Cooperative Oncology Group Study

Authors


  • Dr Kisseberth is currently affiliated with the Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH. Dr Ward is currently affiliated with Gulf Coast Veterinary Oncology, Sarasota, FL. Dr Khanna is currently affiliated with Animal Cancer Investigation, LLC, Bethesda, MD. Dr Obradovich is currently affiliated with the Animal Cancer and Imaging Center, Rochester Hills, MI.

Corresponding author: William C. Kisseberth, DVM, PhD, DACVIM, Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210; e-mail: kisseberth.2@osu.edu.

Abstract

Background: The dosage of carboplatin in cats has been reported anecdotally and experimentally in non-tumor-bearing cats, but the dosage for carboplatin treatment in tumor-bearing cats has yet to be defined in a prospective clinical trial.

Purpose: To determine the maximally tolerated dose (MTD) and dose-limiting toxicosis (DLT) of carboplatin in tumor-bearing cats.

Cats: Fifty-nine cats with measurable solid tumors.

Methods: The starting dose of carboplatin was 160 mg/m2 of body surface area IV. Doses were increased by 20 mg/m2 in cohorts of 3–14 cats until the MTD was reached.

Results: The 59 cats entered into this multi-institutional phase I study received 1 or more doses of carboplatin at various dosages and were evaluated for toxicity, response to treatment, or both. The MTD was 240 mg/m2 and neutropenia was the DLT. For the 1st cycle of treatment in 44 cats evaluated for neutropenia, 6 episodes of grade 3 or greater neutropenia occurred on days 7 (n=1), 14 (n=4), and 21 (n=1). There was no evidence of drug-induced nephrotoxicosis or pulmonary edema. Preliminary evidence of antitumor activity was observed in 7 of 59 (11.9%; 95% CI, 5.6–22.8%) cats evaluated for response to treatment. There was 1 complete response (cutaneous hemangiosarcoma) and 6 partial responses (4 injection site sarcomas, 1 oral squamous cell carcinoma, 1 lymphoma). Responses were of short duration (median, 42 days; range, 7–168 days).

Conclusions and Clinical Importance: The dose of carboplatin recommended to treat tumor-bearing cats is 240 mg/m2 IV every 3–4 weeks.

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