Ribociclib (LEE011) in Preoperative Glioma and Meningioma Patients

Inclusion Criteria * One prior resection of histologically-diagnosed World Health Organization (WHO) Grade III or IV glioma, or WHO grade II or III meningioma. * MRI evidence of disease recurrence * For gliomas, archival tissue must demonstrate: (a) RB positivity on immunohistochemistry OR no RB mutations on next-gen sequencing (NGS), (b) Chromosome 9p21.3 deletion on FISH OR CDKN2A/B/C loss on array CGH OR CDK4/6 or CCND1/2 amplification on array CGH. * For meningiomas, archival tissue much demonstrate (a) RB positivity on immunohistochemistry OR no RB mutations on next-gen sequencing (NGS). * Eastern Cooperative Oncology Group (ECOG) performance status ≤2 * Patients ≥ 18 years of age * Ability to understand and the willingness to sign a written informed consent document (personally or by the legally authorized representative, if applicable). * Patient has voluntarily agreed to participate by giving written informed consent (personally or via legally-authorized representative(s), and assent if applicable). (Written informed consent for the protocol must be obtained prior to any screening procedures. If consent cannot be expressed in writing, it must be formally documented and witnessed, ideally via an independent trusted witness.) * Patients must have recovered from all toxicities related to prior anticancer therapies to ≤ grade 2 (CTCAE v 4.03), provided that concomitant medication is given prior to initiation of treatment with ribociclib. Exception to this criterion: pa…