In vitro activity: AZD1390 is a novel, potent, selective, first-in-class orally bioavailable and CNS penetrant ATM inhibitor with an IC50 of 0.78 nM in cell assays. It is>10,000-fold more selective over closely related members of the PIKK family of enzymes and excellent selectivity across a broad panel of kinases. AZD1390 has the ability to cross the blood-brain barrier (BBB) which makes it suitable for the treatment of intracranial malignancies. AZD1390 radiosensitizes glioma and lung cancer cell lines, with p53 mutant glioma cells generally being more radiosensitized than wild type. AZD1390 is now in early clinical development for use as a radiosensitizer in central nervous system malignancies.

Kinase Assay: AZD1390 is a novel, potent, selective, first-in-class orally bioavailable and CNS penetrant ATM inhibitor with an IC50 of 0.78 nM in cell assays. It is>10,000-fold more selective over closely related members of the PIKK family of enzymes and excellent selectivity across a broad panel of kinases.

Cell Assay: 3000 Cells are seeded into each well of a 384-well plate in RPMI with 10% fetal bovine serum. After 24 hours, plates are Echo-dosed with a semi-log dose dilution of each compound from a top concentration of 1250 nM. One hour after compound dosing, plates are irradiated with 0, 2.5, or 4 Gy. At 1, 6, 24, and 48 hours after irradiation, plates are fixed by adding a 1:1 volume of 8% PFA directly to the medium to give a final concentration of 4% PFA and incubated for 30 min at room temperature before washing three times with phosphate-buffered saline solution (PBSA).