Cisplatin and Gemcitabine Hydrochloride With or Without Berzosertib in Treating Patients With Metastatic Urothelial Cancer

Inclusion Criteria

• •Patients must have histologically or cytologically confirmed metastatic urothelial carcinoma; urothelial cancer derived from the bladder, ureter or upper tract is permitted
• •Patients must have measurable disease, defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter to be recorded for non-nodal lesions and short axis for nodal lesions) as \>= 20 mm (\>= 2 cm) with conventional techniques or as \>= 10 mm (\>= 1 cm) with spiral computed tomography (CT) scan, magnetic resonance imaging (MRI), or calipers by clinical exam
• •Patients must have access to archival tumor tissue for proposed correlative studies; these may be derived from transurethral resection of bladder tumors (TURBT), cystectomy, or biopsy; if archival tissue is not available for proposed correlatives, patients may be enrolled at the discretion of the study principal investigator (PI) (SKP)
• •No prior cytotoxic chemotherapy for metastatic disease; prior immunotherapy is permitted
• •At least 12 months have elapsed since platinum-based peri-operative treatment
• •Karnofsky \>= 70% (Eastern Cooperative Oncology Group \[ECOG\] performance status 0-1)
• •Life expectancy of greater than 3 months
• •Leukocytes \>= 3,000/mcL
• •Absolute neutrophil count \>= 1,500/mcL
• •Platelets \>= 100,000/mcL
• •Total bilirubin within institutional upper limit of normal
• •Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase \[SGOT\])/alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase \[SGPT\]) =\< 2.5 x institutional upper limit of normal
• •Creatinine clearance \>= 50 mL/min by either measured (using the Cockcroft-Gault, Modification of Diet in Renal Disease \[MDRD\] or Chronic Kidney Disease Epidemiology \[CKD-EPI\] formula) or calculated clearance (i.e. glomerular filtration rate \[GFR\])
• •The effects of M6620 (VX-970) on the developing human fetus are unknown; for this reason and because DNA-damage response (DDR) inhibitors as well as other therapeutic agents used in this trial may have teratogenic potential, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation; should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately; men treated or enrolled on this protocol must also agree to use adequate contraception prior to the study, for the duration of study participation, and 6 months after completion of M6620 (VX-970) administration
• •Ability to understand and the willingness to sign a written informed consent document