A small molecule immune checkpoint inhibitor of the adenosine A2A receptor (ADORA2A) with potential antineoplastic activity. Upon oral administration, ciforadenant binds to adenosine A2A receptors expressed on the surface of immune cells, including T-lymphocytes, natural killer (NK) cells, macrophages and dendritic cells (DCs). This prevents tumor-released adenosine from interacting with the A2A receptors on these key immune surveillance cells, thereby abrogating adenosine-induced immunosuppression in the tumor microenvironment. This may stimulate anti-tumor immune responses, resulting in tumor regression.