Canine lymphoma drug granted conditional FDA approval

Doug Thamm, VMD, DACVIM (oncology), at Colorado State University's Flint Animal Cancer Center. (Photo credit: John Eisele/CSU Photography)The U.S. Food and Drug Administration (FDA) has conditionally approved Tanovea-CA1 for the treatment of lymphoma in canine patients. Originally discovered by Gilead Sciences Inc. and developed to treat human lymphoma patients, the drug was acquired by VetDC and refined for veterinary use, according to a release from Colorado State University (CSU).

Tanovea-CA1's active ingredient is rabacfosadine, a cancer-killing substance that was initially developed for humans. Its conditional approval is valid for one year, with renewals possible every year for the next four years, provided VetDC is able demonstrate “progress toward proving ‘substantial evidence of effectiveness' for full approval,” the FDA says.

The CSU release notes that veterinarians with CSU's Flint Animal Cancer Center served as advisors during Tanovea-CA1's development and treated more than 100 dogs with the drug to demonstrate its effectiveness (a total of 350 dogs nationwide underwent treatment).

“Across the board, we saw some positive activity in up to 80 percent of all the lymphoma patients that were treated with this medication,” says Doug Thamm, VMD, DACVIM (oncology), chief scientific officer and cofounder of VetDC, in the CSU release.

One dog involved in the study, a 9-year-old golden retriever with multiple myeloma named Dane, went from being unable to stand or eat or drink to returning to his former activities after five months of Tanovea-CA1 treatments.

A new drug in the oncology toolbox

Dane, a golden retriever with a Tanovea-CA1 success story. (Photo courtesy of Colorado State University)Thamm, the lead researcher of the clinical trials and a survivor of non-Hodgkin's lymphoma, explains that even if drugs initially work, lymphoma returns in 95 percent of dogs.

“So finding new things that we can offer our clients when this lymphoma comes back is incredibly important,” he says in the CSU release. “Having another drug in our toolbox that we can reach for, that we know can actually be quite effective for some dogs and doesn't have to be given very frequently, is a real win.”

According to CSU, Tanovea-CA1 will be available to veterinarians this spring. While conventional chemotherapy requires up to 16 weekly visits, dogs treated with Tanovea-CA1 receive a total of five infusions, each three weeks apart.

Common side effects include “decreased white blood cell count, diarrhea, vomiting, decreased or loss of appetite, weight loss, decreased activity level, and skin problems (hair loss, sores, and scabs),” the FDA release states. Other side effects are possible, so the FDA encourages dog owners and veterinarians to work together to report all side effects potentially related to the drug.