A Pilot Feasibility Study of Oral 5-Fluorocytosine and Genetically-Modified Neural Stem Cells Expressing E.Coli Cytosine Deaminase for Treatment of Recurrent High Grade Gliomas

A Pilot Feasibility Study of Oral 5-Fluorocytosine and Genetically-Modified Neural Stem Cells Expressing E.Coli Cytosine Deaminase for Treatment of Recurrent High Grade Gliomas

RATIONALE: Genetically-modified neural stem cells (NSCs) that convert 5-fluorocytosine (5-FC) into the chemotherapy agent 5-FU (fluorouracil) at sites of tumor in the brain may be an effective treatment for glioma.

PURPOSE: This clinical trial studies genetically-modified NSCs and 5-FC in patients undergoing surgery for recurrent high-grade gliomas.

PRIMARY OBJECTIVES:

I. To determine the safety and feasibility of intracerebral administration of NSCs in combination with oral 5-FC in patients with recurrent high-grade gliomas.

SECONDARY OBJECTIVES:

I. To characterize the relationship between intracerebral and systemic concentrations of 5-FC and 5-FU with increasing NSC dose level.

II. To non-invasively assess the presence of 5-FU in the brain with the use of fluorine (19F)-magnetic resonance spectroscopy (MRS)(no longer in effect as of 5/1/2012).

III. To assess for the possible development of immunogenicity against the NSCs.

IV. To assess the intracerebral distribution of NSCs using iron-labeling as a cellular tracker.

V. To gather preliminary imaging data regarding perfusion permeability parameters and imaging characteristics as shown on magnetic resonance imaging (MRI) studies due to the presence of NSCs in the brain.

VI. To determine, at time of autopsy, the fate of the NSCs.

OUTLINE:

This is a dose-escalation study.

After biopsy or surgery to resect tumor, study patients receive injections of genetically modified NSCs directly into brain tissue on day 0. Patients then take oral 5-FC every 6 hours during days 4-10 which is converted to 5-FU in the brain by the NSCs.

Follow-up MRIs of the brain are performed on days 32, 60, and every 2 months thereafter to assess for response and side effects.

Inclusion Criteria:

• Patient has had a prior, histologically-confirmed, diagnosis of a grade III or grade IV glioma (including glioblastoma, anaplastic astrocytoma, gliosarcoma, anaplastic oligodendroglioma, or anaplastic oligoastrocytoma), or has a prior, histologically-confirmed, diagnosis of a grade II glioma and now has radiographic findings consistent with a high-grade glioma (grade III or IV)
• Imaging studies show evidence of recurrent supratentorial tumor(s)
• The patient must be in need of a craniotomy for tumor resection or a stereotactic brain biopsy for the purpose of diagnosis or differentiating between tumor progression versus treatment-induced effects following radiation therapy +/- chemotherapy
• Based on the neurosurgeon's judgment, there is no anticipated physical connection between the post-resection tumor cavity and the cerebral ventricles
• Patient's high-grade glioma has recurred or progressed after chemoradiation
• Patient has a Karnofsky Performance Status of >= 70%
• Patient has a life expectancy of >=3 months
• If patient requires corticosteroids for the control of cerebral edema, s/he must be on a stable dose for at least 1 week prior to enrollment
• Patient has recovered from toxicity of prior therapies; an interval of at least 12 weeks must have elapsed since the completion of radiation therapy; at least 6 weeks since the completion of nitrosourea-containing chemotherapy regimen; and at least 4 weeks since the completion of a non-nitrosourea-containing cytotoxic chemotherapy regimen; if a patient's most recent treatment was with a targeted agent only; and s/he has recovered from any toxicity of this targeted agent, then a waiting period of only 2 weeks is needed from the last dose and the start of study treatment, with the exception of bevacizumab where a wash out period of at least 4 weeks is required before starting study treatment
• Absolute neutrophil count of >= 1,500 cells/mm^3 and platelet count >= 100,000 cells/mm^3
• Total bilirubin =< 2.0 mg/dl
• Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase [SGOT]) =< 4 times the institutional upper limit of normal
• Serum creatinine =< the institutional upper limit of normal
• Patients must be able to swallow pills
• Patients must be able to understand and be willing to sign a written informed consent document
• Female patients of child-bearing potential and sexually active male patients must agree to use an effective method of contraception while participating in this study
• Women of childbearing potential must have a negative pregnancy =< 2 weeks prior to registration

INCLUSION CRITERIA FOR PROCEEDING TO TREATMENT WITH 5-FC:

• Patients must be tolerating oral intake
• Patients' daily total dose of dexamethasone must be < 12 mg by Day 4

Exclusion Criteria:

• Patients who are currently receiving chemotherapy, radiotherapy, or are enrolled in another treatment clinical trial
• Patients who have anti-human leukocyte antigen (HLA) antibodies specific for HLA antigens expressed by the HB1.F3.CD NSCs
• Patients who are unable to undergo an MRI
• Patients with chronic or active viral infections of the central nervous system (CNS)
• Patients who are allergic to 5-FC or 5-FU
• Patients who have a serious medical or psychiatric illness that could, in the investigator's opinion, potentially interfere with the completion of treatment according to this protocol
• Female patients who are pregnant or breast-feeding
• Patients who have not recovered from the toxicities of prior chemotherapy or radiotherapy
• Patients who require anti-seizure medication but are not on a stable dose of anti-seizure medication for at least 1 week prior to enrollment