A team of scientists from Northwestern University, in the United States, managed for the first time to open the blood-brain barrier to get the most powerful chemotherapy to reach the brain to treat gioblastomas, the most aggressive and common brain tumor.
According to an article in the specialized journal “The Lancet Oncology,” researchers have implanted an ultrasound machine in patients that uses microbubbles to open the blood-brain barrier and penetrate critical parts of the brain so that intravenous chemotherapy can enter.
Exactly, one of the main obstacles so far to treat this deadly tumor was that the most powerful chemotherapy could not penetrate the blood-brain barrier, a microscopic structure that protects the brain from most drugs.
Scientists at Northwestern Medical School ran the process in just four minutes on awake patients, who could go home in just a few hours.
According to the results of this trial, the treatment is “safe” and was “well tolerated” by the patients, some of whom underwent up to six sessions.
Thanks to the opening of the blood-brain barrier, patients received four to six times higher concentrations of chemotherapy in their brains.
The scientists observed this increase with two different drugs, paclitaxel and carboplatin, which are not often used in patients with gioblastoma due to their difficulty in permeating the blood-brain barrier.
In addition, it is the first study that describes how quickly the barrier closes again after being opened with sonication, or the application of ultrasound.
The scientists discovered that 30 to 60 minutes after undergoing the process, the blood-brain barrier closes again, which will make it possible to optimize the sequence of drug delivery with ultrasound activation.
Principal investigator and professor at the university’s Feinberg School of Medicine, Adam Sonabend, called the achievement “a potentially huge breakthrough for patients with gioblastoma.”
The neurosurgeon explained, according to the statement, that the drug currently used against gioblastomas, temozolomide, can cross the barrier but has weak effects.
Difficulty crossing the blood-brain barrier has limited many of the weapons available to fight brain tumors.
Past experiments with paclitaxel injected directly into the brain have offered promising results, but the practice has been associated with brain irritation and meningitis.
The use of ultrasound allows the barrier to open and close again within an hour, providing “a window of time after sonication in which the brain is permeable to drugs circulating in the blood.” according to Sonabend.
The findings of this study are the basis for the second phase of the clinical trial that scientists are carrying out with patients with recurrent glioblastoma, and which aims to investigate whether combined treatment with paclitaxel and carboplatin prolongs the life of these patients .
“Although we have focused on brain cancer, this opens the door to investigate new drug treatments for millions of patients suffering from brain diseases,” Sonabend said.
