A Study to Assess Safety and Efficacy of SOT109 in Patients With Advanced Unresectable or Metastatic Colorectal Cancer

The trial will consist of the following parts: * Part A: a multinational, multicenter, open-label, TITE-BOIN-guided trial to determine the MTD and RP2Ds, to evaluate the safety, PK, and preliminary efficacy of escalating doses of SOT109 in participants with advanced unresectable or metastatic colorectal cancer who have received and/or have been determined to be intolerant of all standard of care therapy known to confer clinical benefit. * Part B: This is a randomized, multinational, multicenter, open-label dose optimization trial evaluating the two recommended doses for optimization (RDOs) identified in Part A. After the determination of the MTD in Part A and identification of RDOs, a randomized dose optimization part will be initiated to evaluate the two selected RDOs and to identify the optimal biological dose that offers the best balance between benefit and risk and to evaluate safety and efficacy of SOT109 in participants with advanced unresectable or metastatic colorectal cancer who have no further standard treatment options.