In addition to achieving selectivity over the other class I isoforms, the PI3Kα specific inhibitor GDC-0326 also achieves a very high level of selectivity over other kinases. GDC-0326 is not an inhibitor of cytochrome P450 enzymes tested.
In vivo
GDC-0326 has consistently low clearance and high oral bioavailability across species tested, enabling significant sustained free drug levels.