Sunnybrook Health Sciences Centre recently announced that their researchers have begun a Phase 2 trial to temporarily open the blood-brain barrier (BBB) using MRI-guided focused ultrasound plus microbubbles in multiple regions of the brain in patients with Alzheimer’s disease.
The BBB is a protective layer of tightly joined cells that lines the blood vessels in the brain and prevents harmful substances, such as toxins and infectious agents, from diffusing into the surrounding brain tissue. It can also prevent therapeutic agents from getting into the brain, which is why research has centered on using focused ultrasound to safely and temporarily disrupt this barrier. However, for this trial, no drugs are being administered as part of these treatments.
The Phase 2 trial builds upon the team’s earlier work where they were able to open the BBB in Alzheimer’s patients for the first time. That smaller trial of six patients was published in Nature Communications in July 2018 and presented at the Alzheimer’s Association’s International Conference. Dr. Lipsman also presented this work at the Foundation’s Symposium in October 2018.
For this trial, the team is targeting different areas of the brain that are critical for cognition, memory, and learning. They are performing pre-treatment scans that allow them to see amyloid deposits –or areas where plaque has accumulated in the brain which is indicative of Alzheimer’s disease.
“It is important to establish that opening the blood-brain barrier in these critical brain structures, repeatedly, is safe,” says Dr. Nir Lipsman, principal investigator of the trial and director of the Harquail Centre for Neuromodulation at Sunnybrook. “We are also determining what influence this may have on amyloid deposits in patients with Alzheimer’s disease. We will measure this using brain scans, spinal fluid and blood analysis, as well as behavioral tests.”
In all, the team expects to enroll 30 patients between the ages of 50 and 85. Only Canadian citizens are eligible to participate.