Clinical Trials

Comparison of the efficacy and toxicity of vincristine versus vinblastine in a combination chemotherapy protocol for feline lymphoma

Lymphoma is one of the most common types of cancer in cats, and it is typically treated with combination chemotherapy.  Chemotherapy carries risks of gastrointestinal side effects and bone marrow suppression.  The drug used to treat feline lymphoma that is most likely to cause gastrointestinal side effects is vincristine.  A similar drug, vinblastine, is associated with fewer and less severe gastrointestinal side effects in people.  The goal of our study is to prospectively evaluate the therapeutic efficacy and toxicity of vinblastine versus vincristine in a combination chemotherapy protocol for feline lymphoma.

Cats will be fully staged, including initial serum cobalamin and folate measurements, then randomized to receive either vincristine or vinblastine as part of their COP-based chemotherapy protocol, and owners will be blinded as to which study group their cat belongs. Owners will be asked to fill out a daily log to record side effects after treatment, and all patients will be treated prophylactically with an anti-nausea medication.  Cats that experience significant gastrointestinal toxicity will be switched to the other treatment group.

Eligible patients:

Cats with intermediate to large cell lymphoma that have not received treatment.

Cats with small cell lymphoma that have failed treatment with prednisone and chlorambucil.

No prior surgery (unless diagnostic) or radiation therapy.

Life expectancy of > 1 month with treatment.

The toxicity endpoint will be the number of cats switched to the opposite treatment group due to toxicity, and the efficacy endpoint will be the number of cats in each group in remission after 6 months of treatment.  Remission duration and survival time between the groups will also be compared.

Cost covered by the study are the vincristine or vinblastine and administration of those drugs for the first 6 months of treatment.  After 6 months, owners will have the option of continuing the full chemotherapy protocol or discontinuing treatment, and patients will be considered off study, but they will be followed to obtain remission duration and survival time information.

This study has been approved by institutional review (POAP #166).  If you have quetions or are interested in more information, please call 215-898-4805, 215-746-2607 or email us at cancertrials@vet.upenn.edu and one of the investigators will return your call.  Please contact us if you have a potential candidate and are interested in this study so that we can facilitate an appointment for you.