A Study to Evaluate Safety and Preliminary Anti-tumor Activity of Debio 0123 as Monotherapy in Adult Participants With Advanced Solid Tumors

Inclusion Criteria: * Part 1 dose escalation only: * Histologically or cytologically confirmed locally advanced or metastatic solid tumors. * Measurable or non-measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 criteria. * Disease progression under or following standard therapy and/or disease for which no available standard therapy of proven benefit. * Part 2 expansion only: * Measurable disease per RECIST version 1.1 criteria for each arm. * Participants (≥18 years old) who progressed or have recurrence of one of the tumor types specified in the study arms following standard therapy according to RECIST version 1.1, or for whom, in the opinion of the Investigator, no effective standard therapy exists. * Arm A: Histologically or cytologically confirmed USC that recurred or progressed following at least 1 prior platinum-based line of therapy for management of advanced or metastatic disease. * Arm B: Histologically or cytologically confirmed, recurrent, high-grade EOC, primary peritoneal cancer, or fallopian tube cancer with cyclin E1 driven selection. Participants must have progressed after at least 1 prior platinum-based therapy for advanced/metastatic disease. * Arm C: Histologically or cytologically confirmed, locally advanced or metastatic solid tumor with biomarker-driven selection. * Part 1 dose escalation and Part 2 expansion: * Accessible tumor for biopsy, and participant willing to undergo tumor biopsy unless …