Inclusion Criteria:

- Newly diagnosed de novo GBM with documented EGFRvIII expression in tumor tissue.

- Gross total resection followed by conventional chemoradiation therapy without
progression of disease.

Exclusion Criteria:

- Presence of diffuse leptomeningeal disease or gliomatosis cerebri.

- Systemic corticosteroid therapy > 2 mg of dexamethasone or equivalent (as defined by
the investigator) per day at study enrollment.

- Patients who have undergone stereotactic radiosurgery prior to or following surgical
resection, or the placement of Gliadel® Wafers.

- Known allergy or hypersensitivity to KLH, GM-CSF or yeast derived products, or a
history of anaphylactic reactions to shellfish proteins.