Additional Study Information: The purpose of this study is to test the safety and effectiveness of study drug PLX51107 on patients with advanced malignancies such as solid tumors, lymphoma, AML or MDS. The participants in this study will be the first people to receive PLX51107. PLX51107 works by targeting and inhibiting certain activities within cells that promote tumor growth. By inhibiting these activities, PLX51107 may help to stabilize or reduce the growth of tumor cells. PLX51107 has shown anti-cancer activity in laboratory studies; however, it is not yet known whether it will work in humans. We are looking for the highest dose of PLX51107 that can be given safely to research subjects/participants with your type of disease. We will also look at how your body absorbs and breaks down PLX51107 and how effective PLX51107 is in treating your disease.