Testing the Combination of Two Anti-cancer Drugs, Peposertib (M3814) and Tuvusertib (M1774) for Advanced Solid Tumors

Inclusion Criteria: * Patients must have histologically confirmed solid malignancy that is metastatic or unresectable and for which standard curative or palliative measures do not exist or are no longer effective. * For the dose escalation and dose expansion phases, patients must have genomic (tumor next-generation sequencing \[NGS\], circulating tumor deoxyribonucleic acid \[ctDNA\], fluorescence in situ hybridization \[FISH\], etc.) or immunohistochemical evidence of inactivating ATM mutations, MYC amplification, mutation of FBXW7, CCNE1 amplification, SWI/SNF member mutation (ARID1A, PBRM1, SMARCA4, ARID2, ARID1b, SMARCB1, SMARCA2, SS18), and ATRX/DAXX. Mutations may be germline or somatic. All mutations/alterations must be approved by the overall principal investigator (PI). Other SWI/SNF mutations may be considered after discussion with the overall PI. * Progression on at least one prior standard therapy. * Age \>= 18 years. Because no dosing or adverse event data are currently available on the use of peposertib (M3814) in combination with tuvusertib (M1774) in patients \< 18 years of age, children are excluded from this study. * Life expectancy \> 3 months. * Eastern cooperative oncology group (ECOG) performance status =\< 2 (Karnofsky \>= 60%). * Measurable disease by response evaluation criteria in solid tumors (RECIST) 1.1 (RECIST) 1.1 non-measurable disease permitted for the dose escalation portion). * Hemoglobin \>= 9 g/dL. * Absolute neutrophil count \>= 1,500/mc…