MSC2490484A is an investigational drug that is being evaluated for the treatment of subjects with advanced solid tumors or chronic lymphocytic leukemia (CLL) that likely differs from other cancers in how it repairs damaged DNA (genetic material). This is a first-in-man Phase I study, which means that it is the first time the study drug is being used in humans. The main purpose is to determine the highest dose that does not cause unacceptable side effects. The second is to determine the appropriate dose to use in future research for subjects with cancer. Othergoals of the study are to learn about the drug's safety and side effects, how it affects the tumor, and how the body processes the drug.