Gleolan is used in adult patients with malignant glioma (a type of brain tumor).  Gleolan helps neurosurgeons to see the tumor more clearly during an operation to remove it from the brain.  Because the number of patients with malignant glioma is low, the disease is considered ‘rare’, Gleolan was designated an ‘Orphan Drug’  The medicine has not been was approved by the FDA on June 6, 2017 and when available commercially will only be used by trained surgeons to allow them to better see the malignant tissue. 


The active substance in Gleolan, 5-aminolevulinic acid, is orally administered, then absorbed by cells in the body, where it is converted into fluorescent chemicals, particularly protoporphyrin IX (PPIX). Since glioma cells take up more of the active substance and convert it more rapidly into PPIX, higher levels of PPIX accumulate in the cancer cells than in normal tissue. When illuminated under blue light of a specific wavelength, the PPIX in the tumor glows an intense red, while the normal brain tissue appears blue. This enables the surgeon to see the tumor more clearly during brain surgery and to remove it more accurately, sparing healthy brain tissue.