A Study of the Specificity and Sensitivity of 5- Aminolevulinic Acid (ALA) Fluorescence in Malignant Brain Tumors

Brain Neoplasms

Brain Neoplasms, 5-ALA, Aminolevulinic acid, Fluorescence, Gliomas, Glioblastoma, Surgery

Extent of resection is a very important prognostic factor affecting survival in individuals diagnosed with a malignant glioma. However, the infiltrative nature of the malignant glioma tumor cells produces indistinct borders between normal and malignant tissues, and the lack of easily identifiable tumor margins confounds attempts at total resection. The investigators propose to identify the borders of malignant gliomas intraoperatively using oral 5-aminolevulinic Acid (5-ALA) which results in fluorescence of the malignant cells and thereby provide an opportunity for more complete tumor resection. When exogenous 5-ALA is provided at increased concentration the tumor cells will become fluorescent under ultraviolet light. This feature identifies the tumor cells intraoperatively and facilitates complete resection. Data collection will include measurement of dose-limiting toxicity, tumor fluorescence, and tumor density. Data analysis will evaluate toxicity, sensitivity, and specificity of 5-ALA. Following completion of the phase 1 portion of this trial, an additional 14 subjects will be entered at the recommended phase 2 dose level in order to further define the above parameters at the recommended phase 2 dose level.

Specific Aims: This study is intended to investigate the utility, safety and efficacy of 5-aminolevulinic acid (5-ALA) induced brain tumor fluorescence during malignant brain tumor resection. Specifically this study is intended to: Establish a safe dose for oral 5-ALA administration. Determine the sensitivity and specificity of 5-ALA mediated fluorescence for malignant glioma tissue in the brain. Background and Significance: There is a considerable body of literature that suggests that completeness of resection is a positive factor for longer term survival in individuals with malignant glioma. Unfortunately, it is often difficult to completely remove a malignant brain tumor because during surgery it is sometimes very difficult to distinguish tumor from normal brain. It would be very helpful if there would be some way to help the surgeon make this distinction. Malignant glioma tumor cells (more so than normal cells) contain the biosynthetic pathways to produce protoporphyrin from a naturally occurring amino acid, 5-aminolevulinic acid (5-ALA). Protoporphyrin is the immediate precursor to hemoglobin (it is hemoglobin without the iron atom) and is fluorescent under blue light. When exogenous 5-ALA is provided at increased concentration, protoporphyrin concentration in the malignant cell increases at a rate far greater than normal brain cells and renders the malignant cell fluorescent red under blue light. This feature distinguishes the tumor cells from normal cells intraoperatively and facilitates complete resection. Recent studies in Germany have confirmed the utility of pre-operative oral 5-ALA and intraoperative brain tumor fluorescence in aiding the resection of brain tumors in individuals with malignant brain tumors. These studies have led to oral 5-ALA to be approved for this indication by the European Medicines Agency, but oral 5-ALA has not been approved for this indication by the United States FDA. This proposal is a phase 1 and phase 2 trial that will hopefully lead to FDA approval of oral 5-ALA for intra-operative visualization of malignant brain tumors. Experimental Plan and Methods: In the phase 1 part of this proposed study, a minimum of 3 to a maximum of 19 patients will be administered oral 5-ALA 4 hours prior to surgery in cohorts of 3 at five escalating doses of 5-ALA (10, 20, 30, 40, or 50 mg/kg). The following data will be collected: * Dose-limiting toxicity data; i.e., nausea, vomiting, liver function, photo-sensitivity * Tumor fluorescence assessed by neurosurgeon * Tumor density from biopsies obtained by the neurosurgeon in will be assessed by neuropathology (Solid tumor, Tumor mixed infiltrating normal brain, No tumor) This trial will evaluate: * single dose toxicity of oral 5-ALA given pre-operatively; * sensitivity and specificity of 5-ALA - Protoporphyrin IX (Pp IX) as an intraoperative fluorescent detection agent and aid for resection of tumor tissue remaining in the walls of the resection cavity of primary and recurrent malignant brain tumors; Following completion of the phase 1 portion of this trial, an additional 14 subjects will be entered at the recommended phase 2 dose level in order to further define the above parameters at the recommended phase 2 dose level.

United States

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