Vaccine to treat osteosarcoma in dogs receives conditional license

Aratana Therapeutics Inc. announced Dec. 20, 2017, that the Department of Agriculture’s Center for Veterinary Biologics has granted a conditional license to Aratana for its vaccine intended to treat dogs with osteosarcoma.

The immunotherapeutic vaccine was developed by Aratana with a Listeria-based antigen delivery system licensed from Advaxis Inc. The vaccine 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.

A 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. Median survival time was 956 days, compared with 423 days for a historical control group.

A field safety study submitted to the USDA for conditional licensure found that the most common adverse events included lethargy, diarrhea, and fever. Four serious adverse events were observed.

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.

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Vaccine holds promise for treating osteosarcoma in dogs (Dec. 1, 2017)