If your friend is in the United States it's worth reaching out to the following places to see what options might be available for clinical trials or treatment options. If these places are out of reach, at the very least, it's worth looking for a nationally designated comprehensive cancer center with a specialized brain tumor program where they'll have access to the newest treatment options.
UCLA Brain Tumor Center: https://www.uclahealth.org/braintumor/default.cfm
Duke Tisch Brain Tumor Center: https://tischbraintumorcenter.duke.edu/
UCSF Brain Tumor Center: http://neurosurgery.ucsf.edu/index.php/brain_tumor_center.ht...
MD Anderson Brain and Spine Center: https://www.mdanderson.org/cancer-types/brain-tumor.html