Able to swallow whole capsules Patients must be able to swallow whole capsules Patients who cannot swallow capsules Patients who are unable to swallow pills/capsules are ineligible Inability to swallow lenalidomide capsules whole; capsules of 13-isotretinoin may be opened Patients must be able to swallow capsules Patients must be able to swallow whole capsules Patients must be able to swallow whole tablets or capsules; nasogastric or gastrostomy tube (G-tube) administration is not allowed Inability to swallow capsules, since capsules cannot be crushed or broken Patients must be able to swallow whole tablets and capsules Patients must be able to swallow whole tablets or capsules; nasogastric or gastrostomy tube (G-tube) administration is not allowed; any gastrointestinal disease which would impair ability to swallow, retain, or absorb drug is not allowed Patients must be able to swallow capsules; nasogastric or gastrostomy feeding (G) tube administration is not allowed 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 capsules Patients must be able to swallow capsules whole Patients must be able to swallow whole capsules Patients must be able to swallow whole capsules Patients with malabsorption syndrome or other condition that would interfere with intestinal absorption; patients must be able to swallow capsules Patients must be able to swallow tablets or capsules; a patient with any gastrointestinal disease that would impair ability to swallow, retain, or absorb drug is not eligible Patients must be able to swallow whole capsules; nasogastric or gastrointestinal (G)-tube administration is not allowed Inability to swallow capsules, since capsules cannot be crushed or broken Ability to swallow pills/capsules Patients must be able to swallow whole capsules 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 Patients must be able to swallow whole tablets or capsules; nasogastric or g-tube administration is not allowed; any gastrointestinal disease which would impair ability to swallow, retain, or absorb drug is not allowed Inability to swallow capsules, since capsules cannot be crushed or broken Inability to swallow capsules, since capsules cannot be crushed or broken Patients must be able to swallow whole capsules Patients must be able to take oral medications; patients must be able to swallow capsules whole without crushing or altering them in any way Patients must be able to swallow capsules