CGT9486 (Formerly Known as PLX9486) as a Single Agent and in Combination With PLX3397 (Pexidartinib) or Sunitinib in Participants With Advanced Solid Tumors

Inclusion Criteria: * Male or female ≥18 years old. * Part 1, Part 2b, Part 2d, and Part 2e: Participants with advanced solid tumors who have tumor progression following standard therapy, have treatment-refractory disease, or for whom there is no effective standard of therapy. * Part 2d: Participants with non GIST solid tumors with KIT mutations, who are TKI naïve or have been previously treated with KIT directed TKI therapy who are appropriate for KIT directed TKI therapy * Part 2a, Part 2c, and Part 2f (GIST participants): Histologically confirmed locally advanced, metastatic and/or unresectable GIST. * Women of child-bearing potential (WOCBP) must have a negative serum pregnancy test at Screening (≤7 days prior to the first dose of study drug) and must agree to use an effective form of contraception from the time of the negative pregnancy test up to 6 months after the last dose of study drug. * Fertile men must agree to use an effective method of birth control during the study and for up to 6 months after the last dose of study drug. * All associated toxicity from previous or concurrent cancer therapy must be resolved (to ≤ Grade 1 or Baseline) prior to study treatment administration. * Willing and able to provide written informed consent prior to any study related procedures and to comply with all study requirements. * Eastern Cooperative Oncology Group (ECOG) Performance Status 0-2 * Life expectancy ≥3 months. * Adequate hematologic, hepatic, and renal function: * Left …