ClearPoint MRI-guided device sheds light on drug delivery to the brain

Recently, Tocagen began enrolling patients in a new Phase I trial of its Toca 511 cancer drug, used to treat aggressive brain tumors, including glioblastoma multiforme. And to deliver the investigational new drug, Tocagen is turning to MRI Interventions' ClearPoint, a visually guided delivery device that would allow for an increased concentration of the targeted Toca 511, allowing it to further "infect" cancer cells and spread throughout a tumor.

The first delivery device of its kind, ClearPoint shows surgeons the target they need to hit and whether they've hit it.

ClearPoint, with help from BrainLab, Siemens and Boston Scientific ($BSX), is an FDA-approved surgical aid that enables the precise placement of instruments and devices guided by an MRI. For the delivery of drugs, ClearPoint can be used to place neuro catheters into the brain in a minimally invasive procedure but can also be used for deep brain stimulation, laser ablation and biopsies, according to the company. It has been used to treat Parkinson's disease, brain cancer, dystonia and epilepsy.

For diseases such as brain cancer or Parkinson's, treatment requires drugs to be delivered directly to the brain, a surgical procedure that traditionally must be performed blind. But with the U.S. company's MRI-guided system, surgeons can visualize drugs marked by a contrast agent as they enter the brain, allowing for a more targeted and safe procedure.

"With ClearPoint, the imaging space is the surgical space," MRI Interventions CEO Kim Jenkins told FierceDrugDelivery. "It aligns the device, such as a catheter, with the target. The surgeon can watch as the device passes through the brain, and a white cloud shows the drug being released."

MRI Interventions' ClearPoint imaging system--Courtesy of MRI Interventions

The frame itself is applied to a patient's head and guides the catheter into the brain. Meanwhile, the patient is in an MRI apparatus, and the video feeds to a monitor used by the surgeon.

Being able to confirm the drug's release at the targeted site is crucial to knowing whether a certain drug is doing what it needs to be doing, Jenkins said. It's the "delivery effect versus the drug effect," he explained.

"It's the real challenge for drug delivery," Jenkins said. "If you're not reaching your target, the drug's not going to work. And by shortening the time it takes to see if a drug is working, we can cut down on systemic side effects."

Currently, besides the ongoing two-part Toca 511 trial expected to be completed within the year, ClearPoint is in use in four other clinical trials, each with new drugs to deliver to the brain. With a soft launch just two years ago, its use in hospitals only started taking off in late 2012, Jenkins said, with 20 hospitals now using the device, 18 of which are in the U.S.

"Our collaboration with Tocagen underscores the advantages of real-time MRI-guided delivery of therapeutic agents to the brain," Jenkins said. "And we are pleased to be a key contributor to the rapid progress being achieved." -- Michael Gibney (email | Twitter)