Inclusion Criteria:

          -  Aged 18 years and older.

          -  Confirmed diagnosis of GBM.

          -  Radiographically or histologically proven progression or recurrence of disease at any
             time after standard of care therapy (radiation, temozolomide, with or without a tumor
             treatment field device).

          -  Tumor debulking or biopsies may be performed to clinical trial enrollment if indicated
             and feasible.

        Exclusion Criteria:

          -  Bevacizumab or targeted therapy within 45 days of enrollment.

          -  Intercurrent immune system disorder such as hypoimmunity (marrow failure, HIV) or
             hyperimmunity (autoimmune disease).

          -  Unable to complete a standard upfront course of chemoradiotherapy due to disease
             progression or intolerance of therapy.

          -  History of Gliadel water, GammaTile or other implanted therapeutic agent.

          -  Concurrent use of tumor treatment field devices (e.g. Optune).