Liquid Biopsy Following BBB Disruption Using Barrier Disrupting Fields in Patients Undergoing Spine Surgery

Objective: To identify new central nervous system (CNS) biomarkers to be used for blood-derived liquid biopsy once the blood-brain barrier (BBB), specifically the blood-arachnoid barrier (BAB), has been transiently disrupted by BDF in patients undergoing spine surgery. Design: Single center (Sheba Medical Center), prospective, controlled. Phase: Feasibility study Endpoints: Efficacy The primary endpoint of the study is the elevation in blood concentration of CNS biomarkers following the study procedure compared to biomarkers detected in cerebrospinal fluid (CSF) of the same subject. Safety The primary safety endpoint will be the overall incidence of BDF procedure-related AEs and SAEs, with severity graded according to CTCAE v5.0 criteria. Study population: The study population will include up to 20 patients undergoing spine surgery. Study period: 24 months. Inclusion criteria: 1. Adult subjects over the age of 18 2. Able to sign informed consent 3. Candidates for intradural tumor resection spinal surgery with intraoperative neuromonitoring. Exclusion criteria: 1. Pacemakers, or other implanted electric medical devices 2. Pregnant or lactating females 3. Major medical, neurologic or psychiatric condition who are judged as unable to fully comply with the study 4. History of skull fractures or previous brain surgery 5. American Society of Anesthesiologists grade \>2 6. Anticoagulants treatment 7. Damage to the dura resulting in CSF leak 8. Patients with seizures/epilepsy Study procedure: 1. Candidates for intradural tumor resection spinal surgery with intraoperative neuromonitoring will be enrolled in the study prior to surgery. 2. The patient will undergo preparation for surgery according to the standard care. 3. Once anesthetized and intubated, electrodes will be attached to the patient's head. 4. After placing the electrodes, when the patient is under anesthesia, a blood sample will be taken prior to BDF. This sample will be used as baseline for BDF. 5. The patient will then undergo a BDF procedure. 6. Additional blood samples will be taken for identification of CNS biomarkers. 7. Surgery will then proceed according to the standard of care. 8. Once the dura is opened, a CSF sample will be taken, in order to compare the blood biomarkers of the specific subject with the CSF biomarkers. 9. The surgery will continue according to the standard of care.

Barrier-disrupting fields (BDF), based on low pulsed electric fields, offer a non-invasive and transient method for selectively opening CNS barriers. We have previously shown that BDF can be applied for efficient delivery of systemically administered drugs into the CNS in rodents. We further demonstrated the application of BDF to enable blood-based detection of brain-derived proteins in rats and mice. The primary endpoint of the study is the elevation in blood concentration of CNS biomarkers following the study procedure compared to biomarkers detected in CSF of the same subject. The concentration of the biomarkers is expected to be elevated in the blood after the BDF procedure. These include specific CSF proteins such as Protein S100A, S100B and prostaglandin D2 isomerase and include additional proteins identified by us in preclinical experiments in rats, and other CNS-derived molecules that were not identified in our preliminary studies. Candidates for intradural tumor resection spinal surgery with intraoperative neuromonitoring will be enrolled in the study prior to surgery. BDF treatment parameters are planned using a simulation package. The distributions of electric fields on the BAB are calculated using a finite elements model, to reach desired electric fields on the BAB needed for inducing BAB disruption. This is done using a simulation package, based on brain MRI after tissue segmentation. Different locations, sizes and distances between the electrodes are modeled in order to reach the optimal setup for obtaining optimal BAB disruption with no BBB disruption. The patient will undergo preparation for surgery according to the standard care. Once anesthetized and intubated, electrodes will be attached to the patient's head. After placing the electrodes, when the patient is under anesthesia, a blood sample will be taken prior to BDF. This sample will be used as baseline for BDF. The patient will then undergo a BDF procedure. Additional blood samples will be taken post BDF for identification of CNS biomarkers. Surgery will then proceed according to the standard of care. Once the dura is opened, a CSF sample will be taken. The surgery will continue according to the standard of care. Adverse Events will be recorded according to CTCAE V 5.