WHAT IS GLeOLAN?
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 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.
HOW DOES GLeOLAN WORK?
The active substance in Gleolan, 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 using optical filters on the surgical microscope to see the tumor more clearly during brain surgery.
About Brain Tumors
Malignant gliomas represent the most common type of primary malignant brain tumor. These World Health Organization (WHO) grade III and IV tumors include anaplastic astrocytoma (AA), anaplastic oligendroglioma (AO), anaplastic ependymoma (AE), and glioblastoma, (GBM) tumors. Malignant glioma tumors are highly invasive and diffusely infiltrative into the surrounding brain parenchyma (Omuro & DeAngelis 2013). The survival of patients with malignant gliomas depends on their specific histopathologic WHO grade. For patients with AAs, the 5-year survival is 25.9%, whereas for patients with GBM, the 5-year survival is less than 5% (Omuro & DeAngelis 2013).
What is Glioblastoma?
Tumors that begin in brain tissue are known as primary brain tumors. Primary brain tumors are classified by the type of tissue from which they originate. The most common brain tumors are gliomas, which comprise a heterogeneous group of neoplasms that differ in several aspects:
- location within the central nervous system
- age and sex distribution
- growth potential
- extent of invasiveness
- morphological features
- tendency for progression
- response to treatments
In adults, the most frequently encountered of these tumors are high-grade or malignant neoplasms. Glioblastoma multiforme (GBM) is by far the most common and most malignant of the glial tumors.