This research study is a Phase I clinical trial. Phase I clinical trials test the safety of an investigational drug. The participants in this study will be the first people to receive PLX7486-TsOH. PLX7486-TsOH works by targeting and inhibiting certain molecules that interact with tumor cells. These molecules assist with tumor growth through various functions, including promoting tumor invasion of organs and nerves. By interfering with these molecules, PLX7486-TsOH may help to prevent tumor invasion and kill tumor cells. PLX7486-TsOH has shown anti-cancer activity in laboratory studies; however, it is not yet known whether it will work in humans. Participants will have a screening procedures done to ensure they are eligble to particpate in the trial. If they are eligible and agree to participate, subjects will take the PLX7486-TsOH by mouth daily, come to the MUSC clinic when specified for study tests and procuedres and maintain a drug diary that will be provided to them. Subjects may continue pariticpating in this study as long as they are tolerating the study drug well and their tumor(s) is not growing.