In antibody-based immunotherapy drugs are used to stimulate the body's own immune cells to attack and destroy the tumor cells. This method is presently used to treat certain types of metastasized cancer, such as melanoma and bladder cancer. However, a disadvantage of the therapy is that the drug is injected into the blood, which will lead to an exposure of the whole body and thereby possible adverse events.
‘The alternative strategy involves administration of the drug directly in or close to the tumor, causing immune cell stimulation and reducing side effects in patients with bladder cancer.’
An alternative strategy would be to administer the drug directly in or close to the tumor, provided that this still leads to the desired immune cell stimulation. In the present study a group of researchers, led by Sara Mangsbo at Department of Immunology, Genetics and Pathology, IGP, had demonstrated that a local immune activation in the tumor area had the same tumor inhibiting capacity as when the drug was delivered in the blood.
'We found that the therapy that we tested in a model system of bladder cancer could stimulate the immune cells to find and attack the cancer cells, even if it was administered locally. These results are very promising since they indicate that it's not necessary to activate the body's whole immune system, but only the one that is relevant in the tumor. This way adverse events caused by the drug can be reduced,' says Sara Mangsbo.
In the study immune activation was achieved by administering blocking antibodies close to the tumor. The results complement the researcher's previous findings where they found that a direct immune stimulatory antibody had superior anti-tumor capacity when used locally at the tumor, as compared to after injection into the blood.
The hope is also that the immune cells, not the drug itself, can find potential metastases and eliminate them. To understand if and how this is happening, further research is required. The present results are based on studies in mice and to determine if drug administration to the tumor results in fewer adverse events in patients, as compared to injections into the blood stream, clinical studies are also needed.