Researchers at Japan’s Hokkaido University have developed an antibody that induces immune responses and therefore tumor regression in dogs with certain cancers.
The advancement is an important new treatment option for dogs with malignant cancers that cannot be treated with existing therapies such as surgery, radiotherapy and chemotherapy.
The antibody has shown promising results in dogs with oral malignant melanoma (OMM) – a highly invasive cancer that affects the mouth and jaw – and undifferentiated sarcoma.
According to Science Daily:
“In humans, some malignant cancer cells express PD-L1 proteins that bind to their receptor PD-1 on T cells, resulting in the suppression of the T cell’s immune function. Thus, PD-L1/PD-1 interaction is considered an ‘immune escape mechanism’ that cancer cells have. Antibodies that block PD-1/PD-L1 binding have proven effective in inducing anti-tumor immune responses and have been widely used in immunotherapy in the last five years. However, in dogs, no such clinical studies have been reported so far.”
Professor Satoru Konnai and his team developed the chimeric anti-PD-L1 immunotherapy by utilizing a rat anti-PD-L1 antibody to create a rat-dog chimeric antibody. They conducted a clinical study involving seven dogs with OMM and two dogs with undifferentiated sarcoma.
The dogs were treated every two weeks. A journal article published in Scientific Reports stated that “one of the OMM dogs showed obvious tumor regression after ten weeks of administration while one dog with undifferentiated sarcoma showed a significant decrease in tumor burden after three weeks.”
None of the nine dogs displayed signs of adverse effects such as allergic reactions, and the data further suggested the treatment may have prolonged survival in dogs with OMM after pulmonary metastasis.
Professor Konnai said:
“Chimerization of the antibody is now proven as a simple and effective strategy to develop therapeutic antibodies in veterinary medicine. Although further clinical studies are needed, other PD-L1-positive cancers could be targeted by the antibody we have developed. Given the similarity between humans and dogs in cancer biology, our study should provide a beneficial model for human preclinical studies.”
H/T to Science Daily
