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 approved by the FDA and when approved will only be used by a trained surgeon to allow them to better see the malignant tissue. The US Food and Drug Administration has agreed to a Fast Track Review of the risk and benefits of Gleolan when the New Drug Application is submitted in 2016.   


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.