Improving cancer immunotherapy using G-CSF-blocking antibodies to overcome myeloid cell-mediated immunosuppression

Half of all Canadians will develop cancer and 1 in 4 will die of the disease. Cancer immunotherapy is a promising solution applicable to multiple types of cancer. The immune system plays a critical role in removing tumour cells. However, tumours escape the immune system to continue growing. Immunotherapy can enhance the immune system's ability to fight cancer and, in some cases, achieve long-lasting remission. However, many cancers do not respond to currently available immunotherapies.

In partnership with ME Therapeutics, we have developed antibodies targeting G-CSF, a protein overproduced by several major cancer types that induces immune suppression and may cause resistance to immunotherapy. Blocking G-CSF reduced the number of colon tumours and normalized immune system function in a mouse model of colon cancer.

We have selected a lead antibody that can successfully bind and inhibit G-CSF both in cell culture and mouse model systems. Our plan is to develop new animal models to test if blocking G-CSF can make resistant tumours sensitive to immunotherapy as well as to evaluate G-CSF in patient tumour tissue. Overcoming treatment resistance will substantially impact primary health care for cancer patients.