The Pharmacokinetic of Capecitabine in Cancer-Bearing Dogs
Canine malignant cancers are a devastating reality to many dog owners. Treatment options are often limited by pet behavior, owner finances and time commitments, and availability of veterinarians who can safely administer chemotherapy. Oral chemotherapy has become increasingly popular because it often costs less than injectable chemotherapy and can be given in the comfort of the patient’s home.
Capecitabine is a well-tolerated, oral chemotherapy drug used in humans for a wide variety of carcinomas including breast cancer, colorectal cancer and head and neck carcinomas. This chemotherapy drug has a short half-life in humans, allowing for quick dose adjustments if side effects are noted. There has been little investigation into the use of capecitabine to treat cancer in dogs, with only one reported case in published literature. That dog was given the capecitabine for seven days without any reported consequences. More research needs to be done, however, on the safety and efficacy of this drug before it can be given to dogs as a treatment for carcinoma.
The purpose of this study is twofold: 1) to measure the levels of capecitabine in the blood after a single dose is given and 2) to document any adverse events as a next step toward using this drug as a treatment for canine carcinomas.
Understanding the concentration of capecitabine in the blood stream will help us know how to dose future dogs with this chemotherapy drug and may lead to improved cancer control. It is unlikely that the one time, single dose of capecitabine, given for this study, will result in effectively treating your dog’s carcinoma. However, if your dog tolerates the dose of capecitabine well, you have the option of continuing this drug outside of the study, at your own expense, and under the supervision of your WSU Veterinary Oncologist.
This study covers the cost for the capecitabine drug, study related blood collection, pharmacokinetic evaluation, and 24-36 hours of boarding (~ $350 value).
This study is being conducted dogs that have been diagnosed with a carcinoma. Dogs may be of any age, breed and gender. To be eligible for this study, dogs must have an appointment with the Oncology Service at the WSU Veterinary Teaching Hospital (WSU VTH) for confirmation/diagnosis of their disease and possible treatment. Dogs enrolled in this study must have a CBC and Serum Chemistry within 2 weeks of enrollment, more than 2,800 neutrophils, and no evidence of any other major disease that would result in a life expectancy of one week or less. After receiving the dose of capecitabine, dogs in this study must spend 24-36 hours at the WSU VTH for routine monitoring and time specific study blood draws.
Once enrolled in the study, your dog will be offered a meal consisting of commercial dog food. Within one hour of that meal, one dose of capecitabine will be administered, orally, either hidden in food or via manual pilling. Following drug administration, blood will be drawn at up to 13 time points over a 24-36 hour period. An intravenous catheter may be placed to aid in blood collection. At each blood draw, no more than 1.5ml (approx. 1/3 teaspoon) will be collected. Dogs will be carefully watched for the first 8 hours following drug administration and will receive a thorough physical examination at least once every 12 hours while in the WSU VTH for the study. They will receive a second meal 8-12 hours after receiving capecitabine after which they will resume their normal feeding schedule. Enrolled dogs will be ready to go home with their owners 24-36 hours after they receive capecitabine.
Owners are responsible for bringing their dog to the WSU VTH for the oncology appointment. They are responsible for the costs associated with the diagnosis of their dog’s carcinoma and for any bloodwork monitoring outside of the 24-36 hour study period.
Clinical Studies Coordinator
DVM, Medical Oncology Resident