Testing the Addition of an Anti-cancer Drug, BAY 1895344, to the Usual Chemotherapy Treatment (Cisplatin, or Cisplatin and Gemcitabine) for Advanced Solid Tumors With Emphasis on Urothelial Cancer

This phase I trial identifies the best dose, possible benefits and/or side effects of BAY 1895344 in combination with chemotherapy in treating patients with solid tumors or urothelial cancer that has spread to other places in the body (advanced). BAY 1895344 may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Cisplatin and gemcitabine are chemotherapy drugs that stop the growth of tumor cells by killing the cells. Combining BAY 1895344 with chemotherapy treatment (cisplatin, or cisplatin and gemcitabine) may be effective for the treatment of advanced solid tumors, including urothelial cancer.

PRIMARY OBJECTIVES: I. To establish the safety and tolerability of the combination of cisplatin + elimusertib (BAY 1895344) in patients with advanced solid tumors. II. To establish the safety and tolerability of the combination of cisplatin + gemcitabine + BAY 1895344 in patients with advanced solid tumors with an emphasis on urothelial carcinoma (UC). III. To establish the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) of cisplatin + BAY 1895344 and cisplatin + gemcitabine + BAY 1895344. SECONDARY OBJECTIVES: I. To evaluate the pharmacokinetic profile of BAY 1895344 (in the doublet and triplet combinations) and gemcitabine (in the triplet) in combination with cisplatin. II. To further evaluate the toxicity of the combination of cisplatin + gemcitabine + BAY 1895344 in patients with UC. III. To evaluate preliminary efficacy observed with cisplatin + BAY 1895344 and cisplatin + gemcitabine + BAY 1895344 in patients with advanced solid tumors, including UC. EXPLORATORY OBJECTIVES: I. To evaluate the correlation of biomarkers, including deleterious deoxyribonucleic acid (DNA) damage response (DDR) gene alterations and circulating tumor (ct)DNA with responses to therapy using whole exome sequencing (WES) and messenger ribonucleic acid sequencing (RNA seq) analysis of archival formalin fixed paraffin embedded (FFPE) tissue, as well as blood. II. To correlate drug exposure with response and/or toxicity. OUTLINE: This is a dose-escalation study of elimusertib. Patients are assigned to 1 of 2 arms. ARM I (DOUBLET COMBINATION): Patients receive cisplatin intravenously (IV) over 1-2 hours on day 1 and 8, and elimusertib orally (PO) once daily (QD) on days 2 and 9. Treatment repeats every 21 days for up to 6 cycles in the absence of disease progression or unacceptable toxicity. ARM II (TRIPLET COMBINATION): Patients receive cisplatin IV over 1-2 hours on day 1 and 8, gemcitabine IV over 30 minutes on days 1 and 8, and elimusertib PO QD on days 2 and 9. Treatment repeats every 21 days for up to 6 cycles in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 30 days, then every 3 months thereafter.