Bone Cancer Vaccine for Dogs Receives Conditional License

The USDA Center for Veterinary Biologics has granted a conditional license to Aratana for its vaccine intended to treat dogs with osteosarcoma.

This study led by Dr. Nicola J. Mason, an associate professor of medicine at the University of Pennsylvania School of Veterinary Medicine, found that the median survival time was 956 days with this vaccine, compared with 423 days in a historical control group.

This immunotherapeutic vaccine, Live Listeria Vector (AT-014), is a freeze-dried formulation of a modified-live, attenuated Listeria strain that activates cytotoxic T cells.

Because the Listeria strain expresses a tumor-associated antigen, the activated T cells are directed to fight cancer cells.

Osteosarcoma in dogs is similar to bone cancer in children in terms of initial signs, progression, and propensity for metastasis as well as possibly the presence on tumor cells of the HER2/neu receptor, which is present in certain other cancers, said these researchers.

"Osteosarcoma is the most common primary bone tumor in dogs and, since there haven't been advances to raise the standard of care in nearly 20 years, dogs often face a poor prognosis," states Ernst Heinen, DVM, Ph.D., Chief Development Officer of Aratana Therapeutics. 

"We are hopeful that our Canine Osteosarcoma Vaccine will be a new tool for veterinary oncologists to prolong survival in dogs with osteosarcoma."

Osteosarcoma (OSA) is the most common primary bone tumor in dogs and cats.  Approximately 80-85% of all canine skeletal tumors are diagnosed as osteosarcomas.

Although the exact etiology is unknown, there has been some evidence that derangement of bone growth or differentiation of new bone at the long bone metaphyses may be to blame.  

They are locally invasive and highly metastatic, which makes them particularly hard to manage.

Canine OSA occurs most often in dogs 7-9 years of age. Large breed dogs are at a much higher risk of developing OSAs (up to 150 times greater risk).

But neutered animals of either sex are twice as likely to develop OSAs as intact animals.

This clinical study evaluated 18 dogs with osteosarcoma that underwent primary tumor removal and received four doses of carboplatin chemotherapy, followed by the therapeutic vaccine every three weeks for three doses.

As required by the USDA for full licensure, Aratana plans to conduct an extended field study in a clinical setting and anticipates starting the study in early 2018.

Initially, the vaccine will be made available for purchase at about two dozen veterinary oncology practice groups that participate in the study.