A Phase I Study of Mebendazole for the Treatment of Pediatric Gliomas

This is a phase I/II study of mebendazole in combination with standard of care agents for pediatric patients with gliomas. Patients with low-grade gliomas will receive a regimen of mebendazole in combination with vincristine, carboplatin, and temozolomide. Patients with high-grade gliomas and diffuse intrinsic pontine gliomas will receive a regimen of mebendazole in combination with bevacizumab and irinotecan. Surgical resection of the tumor will be attempted initially with the goal of achieving a gross total resection without substantial neurologic deficit. Subtotal resection may be preferable depending on the location of the tumor. Optic pathway gliomas and diffuse intrinsic pontine gliomas may remain unresected. Patients with high-grade gliomas or diffuse intrinsic pontine gliomas will undergo local irradiation of their tumor before beginning protocol treatment. Low-grade glioma patients will not receive radiation therapy. Patients 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. Patients with eligible tumors will be consented for enrollment into the study. The study patients will be divided into two groups (low-grade glioma and high-grade/pontine glioma) for the purpose of determining the maximally tolerated dose of mebendazole. These two groups will be treated independently with regard to patient accrual, dose escalation, and evaluation of toxicity. In addition to their standard chemotherapy regimen, patients in both cohorts will receive mebendazole. Mebendazole doses will be escalated from the initial dose level of 50 mg/kg/day divided twice daily, to a second dose level of 100 mg/kg/day divided twice daily, to the final dose level of 200 mg/kg/day divided twice daily, in cohorts of three patients per dose level. A standard "3+3" design will be used for determining dose escalation. Phase I safety monitoring for the low-grade group will take place during a trial period beginning with start of therapy and ending following the tenth week of induction therapy. Phase I safety monitoring for the high-grade/pontine glioma group will take place during a trial period beginning with the start of maintenance therapy through the twelfth week of maintenance therapy (3 cycles). After determination of maximally tolerated dose for each group, the study will continue to evaluate efficacy of this regimen. The study will be amended for the maximally tolerated dose for each group to be used in the remainder of the study. Patients currently on study will continue with maintenance therapy. To document the degree of residual tumor, standard whole brain MRI with and without contrast (gadolinium) will be performed following a specified intervals. Following completion of therapy, patients will continue to be monitored by MRI to assess progression-free and overall-survival.