etrumadenant + quemliclustat

**Etrumadenant + quemliclustat** is a combination of two investigational small molecule drugs developed for cancer immunotherapy. - **Etrumadenant** is a dual antagonist of the adenosine A2a and A2b receptors, designed to block adenosine-mediated immunosuppression in the tumor microenvironment. This action aims to restore the activity of antitumor immune cells by preventing adenosine from suppressing their function[4][5]. - **Quemliclustat (AB680)** is a selective and potent inhibitor of the enzyme CD73, which catalyzes the conversion of AMP to adenosine. By blocking CD73 activity, quemliclustat reduces immunosuppressive adenosine production in the tumor microenvironment, further promoting immune-mediated tumor cell death[2][6][7][8]. The combination of these agents disrupts adenosine signaling via inhibition of both adenosine production (through CD73 blockade) and adenosine receptor activation (through A2a/A2b antagonism), aiming for enhanced antitumor immunity. The drugs are primarily being evaluated in combination with other agents (e.g., zimberelimab, chemotherapies) for the treatment of metastatic colorectal cancer and pancreatic cancer[1][3][7][9].