IRVINE, Calif., April 25, 2013 (GLOBE NEWSWIRE) -- MRI Interventions, Inc. (MRIC) today announced that its ClearPoint(R) Neuro Intervention System is advancing the minimally-invasive precision delivery of the investigational gene therapy drug Toca 511 into malignant brain tumors. The procedure is being performed under real-time visualization and direct magnetic resonance imaging (MRI) guidance at select clinical trial sites. Highlights of the ClearPoint System's application in the Toca 511 trial include:

Improved flow rates during drug delivery. The recently-introduced SmartFlow(R) large-bore cannula increases the drug delivery rate threefold over documented flow rates of the original SmartFlow cannula. Like the original SmartFlow cannula, the new cannula incorporates a stepped tip design to prevent reflux and leakage of the drug outside of the target area, but the new cannula's large bore allows for a clinically meaningful increased rate of delivery.

Precise delivery of the therapeutic agent into the brain tumor. Direct visualization of the procedure in real-time allows surgeons to monitor and confirm delivery to the tumor of Toca 511 mixed with MRI contrast agent at the time of infusion.

Multiple trajectories in a single case. The ClearPoint System includes a SmartFrame(R) targeting device that works with software to allow convenient repositioning of the cannula for multiple trajectories in a single case, and an adjustable head stabilization device that accommodates a wide range of possible entry points.

Tocagen Inc., the clinical trial sponsor, is developing the investigational drug Toca 511 (vocimagene amiretrorepvec) in combination with Toca FC (an investigational extended-release formulation of 5-FC) for the treatment of recurrent high grade glioma, including glioblastoma multiforme (GBM, Grade IV glioma), the most common and aggressive form of brain cancer. Toca 511 is a retroviral replicating vector (RRV) encoding the genetic instructions for the enzyme cytosine deaminase (CD). Toca 511 is designed to selectively infect dividing cancer cells and spread through the tumor after administration. Each patient then begins a course of Toca FC. Within infected cells the CD enzyme converts 5-FC to the anti-cancer drug 5-FU. By producing 5-FU locally, this technology has the potential to produce much higher concentrations of 5-FU in the tumor than can be safely attained with systemic administration.

"So far we successfully delivered Toca 511 precisely to the brain cancer in three patients, all of whom went home the next day," said Manish Aghi, MD, a neurosurgeon and principal investigator for the Toca 511 trial at University of California, San Francisco. "This new ability to deliver large volumes of Toca 511 rapidly into the tumor at flow rates up to 1.8 ml/h (30 microliters a minute) under real-time visualization represents a major technological advance that will enable the neurosurgeon to accurately deliver large quantities of a therapeutic agent, while providing the patient the benefit and safety of a minimally-invasive procedure."

"Our collaboration with Tocagen underscores the advantages of real-time MRI-guided delivery of therapeutic agents to the brain, and we are pleased to be a key contributor to the rapid progress being achieved," said Kimble Jenkins, CEO of MRI Interventions.

Each year approximately 10,000 new cases of GBM are diagnosed in the US. In a recent population-based study, median survival in all diagnosed patients was 10 months.

Tocagen is presently enrolling patients in its investigational Phase I clinical trials. Currently, University of California, San Francisco, University of California, San Diego, Cleveland Clinic Foundation, and Henry Ford Hospital in Detroit are enrolling patients, and additional sites are in the process of joining this study. For more information about participating in this study, please submit an inquiry form to Tocagen.

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MRI Interventions' ClearPoint(R) System Helps Advance Brain Cancer Clinical Trial of Investigational Gene Therapy Drug ...