NEO100 and High-Grade Meningioma

Inclusion Criteria Patient must: 1. Have histologically confirmed WHO Grade II or III meningioma that is residual, progressive or recurrent following at least minimally safe resection and radiation therapy. Metastatic meningiomas are allowed. 1. Residual disease is defined as residual measurable disease (without a requirement for progression). Residual measurable disease is defined by bidimensionally measurable lesions with clearly defined margins by MRI scan(s) with a minimum diameter of 10mm in both dimensions. 2. Progressive disease is defined as an increase in size of the measurable primary lesion on imaging by 25% or more (bidirectional area). The change must occur between scans separated by no more than 24 months. 3. Recurrent disease is defined as new evidence of measurable disease following complete resection (10mm in both dimensions). 2. Be on a stable or decreasing dose of steroids for at least five days prior to the date of informed consent. 3. Participants must have failed maximal safe resection and radiation therapy. 4. There is no limit on the number of prior surgeries, radiation therapy, radiosurgery treatments or systemically administered therapeutic agents, however, these treatment(s) must comply with the following: 1. There is no limit on the number of prior therapies. 2. Prior medical therapy is allowed but is not required. 3. No chemotherapy, other investigational agents within 14 days of study treatment. 4. For prior systemic agents, participants must be at least 4 weeks (or 5 half-lives, whichever is shorter) from other prior cytotoxic chemotherapy (6 weeks from nitrosoureas/alkylating agents) or biologic therapies. 5. No other concurrent receipt of investigational agents or other meningioma-directed therapy (chemotherapy, radiation) while on study. 6. Patients may have been treated with standard external beam radiation or radiosurgery in any combination; however an interval of ≥12 weeks (84 days) must have elapsed from the completion of the radiation therapy to the initiation of study therapy unless there is histopathologic confirmation of recurrent tumor or there is new enhancing tumor outside the radiation field (beyond the high dose region or the 80% isodose line). In addition, there must be subsequent evidence of tumor progression after completion of radiation therapy; 7. An interval of ≥ 28 days and full recovery (no ongoing safety issues) from surgical resection is required; 8. Meningiomas that have resulted from prior radiation therapy are allowed. 9. There must be an interval of ≥ 7 days from stereotactic biopsy; and 5. Participants must have recovered to grade ≤1 or pretreatment baseline from clinically significant adverse events related to prior therapy (exclusions include, but are not limited to alopecia, laboratory values listed per inclusion criteria and lymphopenia) 6. Patient must be ≥ 12 years of age. 7. Patient must have an ECOG performance status of 0-2 or KPS ≥ 60. 8. Patient must have an expected survival of at least three months. 9. Patient must be willing to provide blood sample for pharmacokinetic study (to assess proper administration of NEO100). 10. Patient must have adequate organ and marrow function as defined below: 11. White blood cell (WBC) ≥2000/microliter 12. Absolute neutrophil count (ANC) ≥ 1,500/microliter 13. Platelets ≥ 100,000/microliter 14. Hemoglobin ≥9 gm/dl 15. AST (SGOT)/ALT (SPGT) ≤ 2.5 × laboratory upper limit of normal (ULN) 16. Serum creatinine ≤ 1.5 x laboratory upper limit of normal (ULN) or 17. Creatinine clearance (meas or calc) ≥60mL/min for participants with creatinine levels \>1.5x laboratory upper limit of normal (ULN) 18. Total serum bilirubin ≤ 1.5 x laboratory upper limit of normal (ULN) except participants with Gilbert's Syndrome who can have a total serum bilirubin of \<5 x laboratory upper limit of normal (ULN) 19. MRI (or CT if MRI contraindicated) within 14 days prior to start of study drug. Corticosteroid dose must be stable or decreasing for at least 5 days prior to the scan. If steroids are added or the steroid dose is increased between the date of the screening scan and the start of treatment, a new baseline scan is required. 20. Female patients of child-bearing potential and male patients must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) for 30 days prior to the first administration of study drug, for the duration of study participation, and for 90 days following completion of therapy. Should a female patient become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately. 21. A female of child-bearing potential is any woman (regardless of sexual orientation, not having undergone a tubal ligation, or remaining celibate by choice) who meets the following criteria: 1. Has not undergone a hysterectomy or bilateral oophorectomy; or 2. Has not been naturally postmenopausal for at least 12 consecutive months (i.e., has had menses at any time in the preceding 12 consecutive months). 22. A negative serum pregnancy test will be required of all female patients of child-bearing potential within seven days prior to initiating study drug. 23. A serum pregnancy test will be repeated immediately if pregnancy is suspected. 24. Women must not be breastfeeding. 25. Patient must have the ability to understand, and the willingness comply with scheduled visits, treatment schedule, laboratory testing and other requirements of the study as confirmed by signing a written informed consent document. Exclusion Criteria 1. Patients who have had chemotherapy, targeted small molecule therapy or study therapy within 14 days (or 5 half-lives, whichever is shorter) of study treatment. 2. Patient has completed chemo-radiation within the last 84 days prior to the first administration of study drug, unless new contrast enhancement is outside of radiation field, or there