2. The Turning Point Therapeutics CNS-penetrant ALK kinase inhibitor, TPX-0131, is more potent in vitro than all 5 approved ALK inhibitors against WT-ALK and many ALK resistance mutations, including G1202R and gatekeeper mutation L1196M. This relatively small macrocycle doesnÕt rely on the solvent front region of the kinase for activity allowing it to stay active against solvent front mutations like G1202R. The molecularly efficient structure with low MW, TPSA, and few hydrogen bond donors contributes to its remarkably high brain concentrations (66% of plasma conc. in rat), which may be important in late-stage disease where brain metastases are common. TPX-0131 is currently in Ph. I/II in ALK+, pre-treated cancers (NCT04849273).