Advancement in cancer immunotherapy in veterinary medicine: A review

Cancer is one of the leading cause of death in human beings throughout the world. Attempts to treat cancer are made but not effectively. Surgical removal, use of radiation therapy, chemotherapy and combination of these therapies have been tried to cure cancer but every therapy had its own side effects. Due to potential side effects, these therapies failed to develop as the permanent cure for cancer. Stem cell transplantation has also been attempted as an alternative but the recovery rate was very low. The most recent therapy, nowadays, to treat cancer is immunotherapy in which utilises the immunity of the patient to get modulated in such a way that cancerous cells get killed. So this review enlightens the eminent immunotherapies used for veterinary patients. T cell checkpoint inhibitors, engineered T cells, cancer vaccines and anti-B and anti-T cell antibodies are amongst the important immunotherapies used in human as well as veterinary patient. Inhibition of T cell checkpoint molecules, such as PD-1 and CTLA-4, using monoclonal antibodies are the most advanced techniques developed in humans. These significant immunotherapies have achieved notable success against some of the advanced tumors in humans, including melanoma, renal cell carcinoma and non small cell lung cancer. However, a recent clinical trial with a caninized monoclonal antibody against canine PD-L1 showed response in canine melanoma.