Protocol PLX108-05 is a Phase 1/2 open-label, sequential dose escalation (Part 1) followed by cohort expansion (Part 2) design at the recommended phase 2 dose established in Part 1 (i.e. 3,000 mg/day). Treatment with PLX3397 will consist of continuous oral administration in 28-day cycles until unacceptable or dose-limiting toxicity, disease progression or relapse, patient death, Investigator decision, or voluntary withdrawal.