Unable or unwilling to swallow napabucasin capsules daily. Patients must be able to swallow capsules Patients unable to swallow capsules whole are not eligible; nasogastric or gastric (G) tube administration is not allowed Patients must be able to swallow whole capsules Patients must be able to swallow intact capsules Patients must be able to swallow intact capsules Able to swallow capsules Inability to swallow capsules or known gastrointestinal malabsorption Able to swallow ribociclib capsules Patient must be able to swallow capsules Able to swallow capsules Able to swallow capsules The subject is unable to swallow capsules. Inability to swallow capsules Inability to swallow gelatin capsules, or any medical condition that interferes with normal gastrointestinal absorption Patients must be able to swallow capsules; nasogastric or gastrostomy feeding (G) tube administration is not allowed Unable or unwilling to swallow napabucasin capsules daily. Inability to swallow capsules, since capsules cannot be crushed or broken Patients must be able to swallow capsules Patient must be able to swallow capsules Are able to swallow capsules Patients must be able to swallow intact capsules Patients must be able to swallow capsules Are able to swallow capsules. Able to swallow intact capsules Inability to swallow capsules, since capsules cannot be crushed or broken The subject is unable to swallow capsules Ability to swallow capsules unless enrolled in Part E Part E: Any patient unable to swallow capsules who otherwise meet all other eligibility criteria for Part A (expansion) B, C or D Patients must be able to swallow whole capsules; nasogastric or gastrointestinal (G)-tube administration is not allowed Able to swallow capsules Patients must be able to swallow AZD1775 capsules Ability to swallow and retain capsules. Ability to swallow capsules Inability to swallow capsules, since capsules cannot be crushed or broken PART 2 GROUP 1 INCLUSION CRITERIA: Subjects taking capsule formulations must be able to swallow capsules PART 2 GROUP 2A INCLUSION CRITERIA: Subjects taking capsule formulations must be able to swallow capsules PART 2 GROUP 3 INCLUSION CRITERIA: Subjects taking capsule formulations must be able to swallow capsules Patients must be able to swallow intact capsules whole Patient must be able to swallow capsules Inability or unwillingness to swallow capsules Unable to swallow capsules Patients with malabsorption syndrome or other condition that would interfere with intestinal absorption; patients must be able to swallow capsules Patient must be able to swallow capsules Patients who are unable to swallow oral gel capsules are not eligible Able to swallow capsules, with no surgical or anatomic condition that will preclude the patient from swallowing and absorbing oral medications Participants must be able to swallow capsules Able to swallow capsules whole (pomalidomide capsules cannot be crushed, dissolved or broken) Patients must be able to swallow whole capsules Patients must be able to swallow capsules Patient must be able to swallow capsules Inability to swallow lenalidomide capsules whole; capsules of 13-isotretinoin may be opened Patients must be able to swallow capsules Must be able to swallow ribociclib capsules Must be able to swallow capsules and have no evidence of gastrointestinal (GI) tract abnormality that would alter the absorption of oral medications Patients must be able to swallow capsules whole PHASE II: Patients must be able to swallow capsules whole Known inability to swallow capsules Patients must be able to swallow whole capsules Patients must be able to swallow capsules whole Part C: Patients must be able to swallow intact capsules Patients unable to swallow whole capsules Able to swallow whole capsules Patients taking the capsule formulation must be able to swallow capsules; feeding tube administration is allowed for patients receiving the oral solution (OS) are able to swallow capsules Patients must be able to swallow whole capsules Inability to swallow capsules. Patients must be able to swallow whole capsules Subject is able to swallow capsules Unable or unwilling to swallow BBI608 and/or BBI503 capsules daily Unable or unwilling to swallow BBI608 capsules daily. Must be able to swallow lenalidomide capsules Unable or unwilling to swallow BBI608 capsules daily Are able to swallow capsules Unable to swallow capsules Patients must be able to swallow capsules Inability to swallow capsules Patients must be able to swallow whole capsules Inability to swallow capsules. Unable or unwilling to swallow BBI608 capsules daily. Able to swallow capsules Unable or unwilling to swallow BBI503 capsules daily Unable or unwilling to swallow BBI608 capsules daily. Patients who cannot swallow capsules Patients must be able to swallow intact capsules Inability to swallow capsules or known gastrointestinal malabsorption Ability to swallow oral capsules Are able to swallow capsules Unable or unwilling to swallow the complete daily dose of ARQ 087 capsules Patients must be able to swallow the vorinostat capsules or have a feeding tube to allow for drug suspension Inability to swallow the HKI-272 capsules Able to swallow capsules Able to swallow capsules Inability to swallow capsules Patients must be able to swallow whole capsules; capsules must not be crushed or chewed; capsules must not be opened RECURRENT/ PROGRESSIVE DIPG (STRATUM 1): Patient must be able to swallow capsules whole NON-PROGRESSED DIPG (STRATUM 2): Patient must be able to swallow capsules whole Inability to swallow oral capsules Inability or unwillingness to swallow capsules Able to swallow capsules and maintain adequate hydration Patients will be excluded if they are unable to swallow capsules whole. Must be able to swallow whole capsules Unable or unwilling to swallow BBI608/placebo capsules daily. Patients must be able to swallow capsules Inability or unwillingness to swallow capsules Patients must be able to swallow whole capsules PHASE I: >= 3 years and =< 18 years of age at the time of study enrollment, if able to swallow whole capsules Inability to swallow capsules, since capsules cannot be crushed or broken Patients must be able to swallow capsules whole; nasogastric or gastrostomy (G) tube administration is not allowed Able to swallow whole capsules Patients must be able to swallow capsules Subject is able to swallow enzalutamide capsules and comply with study requirements. Patients must be able to swallow either intact capsules or mini-tabs without chewing Patient must have the ability to swallow multiple capsules Able to swallow capsules Able to swallow oral capsules without difficulty. Able to swallow capsules Patient must be able to swallow capsules (phase III only) Inability or unwillingness to swallow capsules Patients must be able to swallow whole capsules Unable or unwilling to swallow BBI608 capsules daily