MedicalResearch.com Interview with: Nataniel Lester-Coll, MD Chief Resident in Radiation Oncology at Yale New Haven, Connecticut  MedicalResearch.com: What is the background for this study? What are the main findings? Response: Recurrent Glioblastoma Multiforme (GBM) has limited treatment options and the prognosis is poor. Mibefradil diydrochloride was identified using a high-throughput compound screen for DNA double stranded break repair inhibitors. Mibefradil was found to radiosensitize GBM tumor cells in vitro and in vivo. Based on these findings, we sought to determine the maximum tolerated dose of mibefradil and radiation therapy in a Phase I recurrent GBM study. Eligible patients with recurrent  Glioblastoma Multiforme received Mibefradil over a 17 day period, with hypofractionated radiation (600 cGy x 5 fractions). There are 18 patients currently enrolled who have completed treatment. Thus far, there is no clear evidence of radionecrosis. A final dose level of 200 mg/day was reached as the maximum tolerated dose. The drug was very well tolerated at this dose. We saw intriguing evidence of enhanced local control in selected cases. Patients enrolled in a translational substudy who received Mibefradil prior to surgery were found to have adequate levels of Mibefradil in resected brain tumor tissue. (more…)