-STUDY CLOSED- Palladia or Palladia plus Radiation Therapy in Cats with Oral Squamous Cell Carcinoma

Purpose of Study

The purpose of this study is to identify the activity of toceranib phosphate (Palladia) alone or as a radiation sensitizing agent in the treatment of feline oral squamous cell carcinoma.


Feline oral squamous cell carcinoma (SCC) accounts for ~90% of feline oral tumors and at this time there is no effective treatment. Median survival time in untreated cases is approximately 60 days. Radiation therapy or chemotherapy alone is generally ineffective. The combination of radiation therapy with radiation sensitizers or chemotherapy has improved response rates and/or survival times in several studies, however overall survival times still remain in the 4-6 month. Therefore, new therapeutic approaches are needed. Preliminary data presented at the 2010 Annual Veterinary Cancer Society Meeting indicates that Palladia a new anti-cancer drug that works by blocking the signaling of several receptors, including VEGFR2 and PDGFR is well tolerated in cats and has biologic activity against SCC, sarcomas, and mast cell tumors. Inhibition of VEGFR2 and PDGFR works to slow down or block the growth of new blood vessels in tumors. Although the presence of VEGF and VEGFRs in human oral SCC is well documented, it has not yet been evaluated in feline cases. However, evidence continues to accumulate that drugs such as Palladia have the ability to sensitize cancer cells to radiation therapy.  Furthermore, evidence suggests that Palladia is safe when combined with radiation in dogs, supporting its use in combination protocols. Therefore, the purpose of this study is to identify the activity of Palladia alone or as a radiation sensitizing agent in the treatment of feline oral SCC.

Inclusion Criteria

To qualify for enrollment in this study, cats must:

  • Have histologically or cytologically confirmed diagnosis of oral SCC
  • Have a life expectancy of at least 6 weeks
  • Have no evidence of metastatic disease at the time of enrollment
  • Have no other serious health problems that are incompatible with the study (as renal, cardiac or hepatic insufficiency)

Study Design

Cats with a confirmed diagnosis of SCC will be placed on Palladia at a 3-3.25 mg/kg dose every other day. The owners will then decide whether they wish to treat their pet with radiation therapy concomitantly or remain on Palladia as a single treatment. For those that choose radiation therapy, treatments will be given twice per week for 3 consecutive weeks, for a total of 6 treatments. Cats will need to be rechecked weekly for 3 weeks, then at week 5 and monthly thereafter. At each recheck, a physical examination, complete blood count, toxicity assessment and drug accountability will be performed. The total duration of the study is 1 year.

Client Compensation

The study will provide Palladia free of cost for duration of study

Client Cost

Owners are responsible for the fees associated with the radiation therapy treatment, recheck visits and tests performed. Owners are also responsible for any additional costs that arise from other medications, and the treatment of potential complications during the study

Contact Information

Please contact the Clinical Trials Office at the Veterinary Medical Center (clinicaltrials [at] cvm [dot] osu [dot] edu) for more information about this study.