molecules of the month

4. The Artios Pharma selective allosteric Pol_ DNA polymerase inhibitor, ART558, induces synthetic lethality in BRCA-mutant cancer cells and enhances PARP inhibitor activity. Defects in the 53BP1/Shieldin complex (which cause PARPi resistance) result in sensitivity to Pol_ inhibition. The molecule is orally active in a mouse xenograft model in a BRCA mutant line and Artios aims to have a first-in-human study for a Pol_ inhibitor this year. With the growing success of PARP inhibitors and the synthetic lethality concept there will be interest in seeing clinical data with this new synthetic lethal mechanism.