PILOT STUDY TO ASSESS THE EFFECT OF VARDENAFIL ON BLOOD BRAIN AND BLOOD TUMOR PERMEABIITY (IRB 22499)
Every year approximately 17,000 people in the US are diagnosed with primary, malignant brain tumors and 200,000 people are diagnosed with metastatic brain tumors. Despite standard treatment with surgical resection, radiation, and/or chemotherapy, these tumors have a bleak prognosis.
Efficacy of chemotherapy is largely limited by the blood-brain barrier, which prevents the entry of most chemotherapeutic agents into the brain. Efforts have been made to identify pharmacologic agents that can increase the permeability (ie, leakiness) of the blood-blood barrier in order to improve drug delivery. Vardenafil (Levitra) is a compound that blocks the function of an enzyme called PDE-5, and by doing so, the normally tight seal of the blood-brain barrier becomes more leaky for a short period of time. This window of increased leakiness may represent an optimal time to deliver chemotherapy.
Vardenafil is well-tolerated drug approved by the FDA for erectile dysfunction. This pilot study seeks to assess the effect of vardenafil on the blood-brain barrier using an imaging modality called dynamic-contrast enhanced MRI (DCE-MRI). DCE-MRI is a well-established and safe imaging modality in which several scans of the brain are performed over a short period of time. This allows us to study how blood-brain barrier leakiness changes over time.
Patients who already have a clinic appointment in the Neurosurgical Institute and fit eligibility criteria will be approached to participate in this study. The study PI or Co-Investigator will discuss the study with the patient and give them a consent form. Patients will have the option to take the consent form home and review with friends and family. Once all patient questions have been addressed and the individual is willing to participate in the study, one of the study investigators will obtain the patient's informed consent.
Approximately 20 patients with malignant primary or metastatic brain tumors will participate in this study at CSMC.
After patients have consented, screening for the study will use information obtained from previously obtained standard-of-care procedures documented in the patient’s medical record, including history and physical examination, neurologic exam, and standard laboratory tests (CBC with platelets and Complete Metabolic Panel). Females of child-bearing age will have a serum pregnancy test to ensure they are not pregnant before participating in this trial. Approximately 4cc (1 teaspoon) of blood will be taken for this test. Patients will then be scheduled for a single study visit. During the visit they will undergo a history and physical examination including neurological exam (Karnofsky Performance Status - interview format) as part of the screening procedures for this study. Patients will then take 20 mg of vardenafil by mouth, and one hour later a research-related DCE-MRI scan will be performed at the single study visit. Subjects will receive an intravenous injection of the contrast agent Gd-DTPA before they undergo the MRI scan. This contrast agent not only makes the identification of abnormalities more accurate, but may also provide additional information about a subject's condition that might otherwise have gone undetected.
Surasak Phuphanich, MD, FAAN
Director, Neuro-oncology Program