CD73 is the primary enzymatic producer of immunosuppressive adenosine in the tumor microenvironment, and high CD73 expression is associated with significantly poorer prognosis in several tumor types.
ATP is released from tumor cells in response to cellular stresses.
Enzymatic action of CD39 and CD73 convert extracellular ATP into adenosine, which elicits immunosuppressive effects on tumor-infiltrating immune cells.
Quemliclustat is a potent and selective small molecule inhibitor of CD73 that has been shown to block the production of adenosine.
The reduction of adenosine restores immune function.
Once the immunosuppressive effects of adenosine are removed, activation of anti-tumor immune cells may be restored resulting in tumor cell death.