Adenosine is a powerful immunosuppressive substance produced inside tumors as a result of rapid cancer cell turnover and, in some cases, in connection with certain anti-tumor interventions, such as chemotherapy and radiation.
The A2a/A2b receptors, expressed on the surface of immune cells, mediate the immunosuppressive effects of adenosine.
ATP is released from tumor cells in response to cellular stress and is converted to adenosine in the extracellular tumor microenvironment.
Adenosine elicits immunosuppressive effects through direct interaction with the A2a and A2b receptors on tumor-infiltrating immune cells.
Etrumadenant is a small molecule, selective dual antagonist of the A2a and A2b receptors that can prevent adenosine-mediated immunosuppression.
Once the immunosuppressive effects of adenosine are blocked, activation of anti-tumor immune cells may be restored resulting in tumor cell death.