Study of Tuvusertib (M1774) in Combination With DNA Damage Response Inhibitor or Immune Checkpoint Inhibitor (DDRiver Solid Tumors 320)

This is an open-label, multicenter, clinical study conducted in multiple parts to establish the safety, tolerability, Pharmacokinetic/Pharmacodynamic (PK/PD) profile, maximum tolerated dose (MTD) combinations (if observed) and recommended dose for expansion (RDE) combination for tuvusertib in combination with lartesertib (in Part A1), food effect on the PK of lartesertib as monotherapy followed by treatment with tuvusertib in combination with lartesertib in participants with specific tumor types (in Part A1.1), relative bioavailability of a tuvusertib tablet formulation vs capsule formulation followed by treatment with tuvusertib (capsule) in combination with lartesertib in participants with specific tumor types (in Part A1.2), safety/tolerability and early signs of clinical activity of tuvusertib (capsule)and lartesertib in combination in participants with prostate cancer harboring loss of function (LoS) mutation in the gene ATM based on historic data collected prior to prescreening in circulating tumor (ct) DNA (liquid biopsies) or tumor biopsies (in Part A2), safety/tolerability and early signs of clinical activity of tuvusertib and lartesertib in combination in participants with endometrial cancer harboring LoS mutation(s) in the gene ARID1A based on historic data collected prior to prescreening in ctDNA (liquid biopsies) or tumor biopsies (in Part A3), the relative bioavailability of a tuvusertib tablet formulation (TF1, test) compared to a capsule formulation (reference) will also be investigated (in Part A2/A3), and identify a potential set of MTD combinations, and establish the RDE for the combination of tuvusertib and avelumab in participants with metastatic or locally advanced unresectable solid tumors (in Part B1).