• Posted June 27, 2023

Combo Therapy Could Treat Oral Melanomas in Dogs

Could a treatment combo that improves the odds against melanoma for humans work in dogs?

Yes, claims a new study that found radiotherapy followed by immunotherapy extended survival in canine melanoma patients.

Melanomas in dogs are similar to human melanomas. An effective treatment for human melanomas is a combination of radiotherapy and immunotherapy. The researchers from Japan wanted to see if the same treatment could help their canine friends.

A team of researchers led by Dr. Satoru Konnai, at Hokkaido University, investigated the effects of this therapy in dogs.

"One of the means that tumors employ to protect themselves is by inducing over-expression of molecules that suppress the immune response, such as PD-1 and PD-L1," Konnai said in a university news release.

"Immunotherapy that targets these molecules and blocks their function has a response rate of 14% for canine oral malignant melanoma [OMM]. Studies in humans have shown that combining anti-PD-L1 immunotherapy with radiotherapy -- where the radiation is focused on the tumor -- increases survival in humans, and we wanted to examine if this was true in dogs as well," he explained.

For the study, the team analyzed data from 39 dog patients with stage 4 pulmonary OMM treated with the anti-PD-L1 antibody c4G12 between March 2016 and September 2021. Pulmonary OMM is oral cancer that has spread to the lungs.

"The group that had received radiotherapy prior to c4G12 had better overall survival compared to the group that received just c4G12," Konnai said. "Concurrent treatment had no benefits compared to prior radiotherapy."

Future studies will examine the validity of these findings in larger sample sizes and also focus on the best regiment for survival.

The report was published recently in the journal Cancers.

More information

For more on oral cancers, see the American Cancer Society.

SOURCE: Hokkaido University, news release, June 22, 2023