The U.S. Food and Drug Administration (FDA) has approved Gleolan (aminolevulinic acid hydrochloride, ALA HCl) for use to enhance the visualization of malignant tissue during glioma surgery.
Gleolan, an optical imaging agent, is used as an adjunct for visualization of malignant tissue during glioma surgery, and is the first-ever fluorescing agent approved for use with gliomas.
Gliomas are tumors derived from the support cells of the central nervous system, also known as glial cells. High grade gliomas (HGG) are destructive and expand rapidly, and an estimated 160,000 people are diagnosed with them every year. The 2 most common forms of HGG are glioblastoma (GBM) and anaplastic astrocytoma.
As verified by histopathology of biopsied fluorescent tissue, 3 prospective studies showed that ALA-induced fluorescence has high predictive value for visualization of malignant tissue. 5 clinical studies support the safety of gleolan, the sum of which included 527 patients with glioma who received ALA.
Gliomas typically have a poor response to radiation treatment, and surgery is not often possibile. Many chemotherapy agents cannot cross the blood brain barrier, but those that can, such as 5-fluorouracil (5-FU), often have extreme side effects that limit their use.
Per the FDA, gleolan is connected to such risks as phototoxic reactions, hypersensitivity reactions, and interpretation errors (false negatives and false positives). An escalation in the extent of resection might escalate the chance of severe short-term neurologic deficits, and adverse reactions that occurred in > 1% of patients in the week following surgery were pyrexia, hypotension, nausea, and vomiting.
Other adverse reactions occurring in < 1% of patients in the first 6 weeks after surgery were chills, abnormal liver function test, and diarrhea.
At present, GBM patients currently survive an estimated 16 months after diagnosis. Median survival after recurrence is 7-to-9 months.