Inclusion Criteria:

          1. Age > 1 year of age and ≤ 21 years of age

          2. Diagnosis

             2.1. Group A - Low-grade Glioma Group:

             Histology: Biopsy-proven:

               -  Pilocytic Astrocytoma

               -  Fibrillary Astrocytoma

               -  Pilomyxoid Astrocytoma

               -  Pleomorphic Xanthoastrocytoma

               -  Other low grade astrocytomas

             Children with optic pathway tumors must have evidence of progressive disease on MRI
             and/or symptoms of deteriorating vision or, progressive hypothalamic/pituitary
             dysfunction or, diencephalic syndrome or precocious puberty.

             Patients with relapsed low-grade gliomas who have been previously treated with
             chemotherapy will be eligible for the study provided they have not previously failed
             therapy with any of the chemotherapeutic agents used in this study.

             2.2 Group B - High-grade Glioma/Pontine Glioma Group:

             Histology: Biopsy-proven

               -  Anaplastic astrocytoma

               -  Glioblastoma multiforme

               -  Gliosarcoma.

             Patients with primary spinal cord malignant gliomas are eligible.

             For primary brainstem tumors, histologic verification is not required. Patients are
             eligible when diagnosed with clinical and radiographic (MRI) evidence of tumors which
             diffusely involve the brainstem. Patients with tumors which intrinsically (greater
             than 50% intra-axial) involve the pons or pons and medulla or pons and midbrain or
             entire brainstem are eligible. Tumors may contiguously involve the thalamus or upper
             cervical cord.

          3. Timing of therapy:

             Patients must be enrolled before treatment begins. Treatment must start within 14 days
             of study enrollment.

             All clinical and laboratory studies to determine eligibility must be performed within
             7 days prior to enrollment unless otherwise indicated in the eligibility section.

          4. Adequate hematologic, renal, liver function as demonstrated by laboratory values.

          5. Negative pregnancy test in women of childbearing potential within 7 days of initiating
             investigational therapy

          6. Life expectancy ≥ 3 months

          7. Concurrent medications: It is recommended that patients are weaned off or are on a
             tapering dose of corticosteroids before starting therapy on study.

          8. Patient or legal guardian must give written, informed consent or assent (when
             applicable)

          9. Recent mothers must agree not to breast feed while receiving medications on study.

        Exclusion criteria:

          1. Age < 1 year or > 21 years

          2. Patients who have known allergy to mebendazole or benzimidazole class drugs.

          3. Patients who have previously had a severe side effect, such as agranulocytosis and
             neutropenia, in conjunction with previous mebendazole or benzimidazole class drug for
             a parasitic infection .

          4. Patients who are taking metronidazole and cannot be safely moved to a different
             antibiotic greater than 7 days prior to starting mebendazole therapy.

          5. Pregnant female patients are not eligible for this study. Pregnancy tests with a
             negative result must be obtained in all post-menarchal females.

          6. Lactating females must agree they will not breastfeed a child while on this study.

          7. Males and females of reproductive potential may not participate unless they agree to
             use an effective contraceptive method and continue to do so for at least 6 months
             after the completion of therapy.

          8. Patients who are unable to take oral medications because of significant vomiting will
             be excluded.

          9. Group A - Low-grade Glioma Group ONLY:

             Patients who have failed prior chemotherapy with vincristine, carboplatin, or
             temozolomide for this tumor are excluded.

             Patients with Neurofibromatosis Type 1

         10. Group B - High-grade Glioma/Pontine Glioma Group ONLY:

        Patients who failed prior chemotherapy with bevacizumab or irinotecan for this tumor are
        excluded.

        Patients who progressed on or within 12 weeks after completion of radiotherapy are
        excluded.

        Patients with a history or current condition that would preclude the use of bevacizumab