Patients with DIPG who have received adequate radiation therapy but have not yet progressed will be enrolled in the currently open Stratum 2. Panobinostat will be administered every other day, 3 times/week, every other week p.o. preferably on a Monday/Wednesday/Friday schedule. Total 4 weeks will constitute one course. Treatment will continue for up to two years (26 courses) unless the patient experiences progressive disease, unacceptable toxicity or any of the off-treatment criteria.