Checkpoint Kinase 2 Gene Mutation

This is a single center, phase I/Ib clinical trial evaluating the combination of the poly adenosine diphosphate-ribose polymerase (PARP) inhibitor olaparib with the DNA methyltransferase (DNMT) inhibitor ASTX727, which is an oral formulation of decitabine with cedazuridine (a cytidine deaminase inhibitor that allows for oral administration). The study population consists of adults with advanced/metastatic solid tumor malignancies with germline or somatic mutations in the HRR pathway (i.e., BReast CAncer gene 1 (BRCA1), BReast CAncer gene 2(BRCA2), Partner And Localizer of BRCA2 (PALB2), ATM, and/or Checkpoint kinase 2 (CHEK2) mutations).