Drug delivery breakthrough for brain tumour therapy
tumour by developing a new medical device that it claims is the
first ultrasound-based system to allow drug delivery to the brain.
Pre-clinical trials showed that the new device, developed by US-based Perfusion Technology, could safely open the blood-brain barrier (BBB) to enable the delivery of therapeutic drugs directly into the brain, using a low-intensity ultrasound technology.
More than 200,000 people are diagnosed with a primary or metastatic brain tumour in the US each year, according to the Brain Tumour Society.
However, treating these patients is generally a challenge as the BBB blocks most therapeutics drugs from entering the brain, making it difficult to treat brain cancer and spurring researchers to search for methods of breaching the blood-brain barrier without damaging it.
Currently used methods that can bypass the BBB - including injecting sugar solution (Mannitol) into a brain artery, inserting catheters to pump drugs directly into the brain and implanting drug eluting wafers after surgical tumor removal - are usually risky, highly invasive, expensive, can lead to irreversible side effects or allow only a limited distribution of drug within the brain tissue.
Perfusion Technology claims that its new ultrasound-enabled drug delivery to the brain is easy to use, combines non-invasive ultrasound with intravenous-administered drugs, does not require either surgery or image guidance, and is relatively inexpensive.
"We can control how much of a patient's brain will be affected by the ultrasound, allowing us to tailor the treatment to the disease," Al Kyle, president and CEO of Perfusion Technology, told In-PharmaTechnologist.com.
"And since the effect is not limited to tumor tissue, the method will eventually be used for treatment of other diseases."
In practice, the ultrasound device is placed on the patient's head, while he receives a drug treatment, and opens the BBB temporarily, allowing the drug to pass into the brain.
Two or more ultrasound beams are directed to the region of the brain requiring therapy, for about an hour.
Each ultrasound source is equipped with a disposable contact sensor to make sure the targeted area is properly exposed to the ultrasound.
"As a result, the BBB becomes permeable for larger molecules, without damage to endothelial cells or the surrounding tissue," said Kyle.
"The disruption is reversible and provides a safe, effective approach for enhancing drug delivery to the brain."
Kyle added that although the first application for the device is brain cancer, stroke patients could also benefit from the new system as well as epilepsy patients, who could potentially be protected from seizures.
The next step for the firm is to prove feasibility in human patients, and the firm is expecting to start clinical trials at the end of next year.
A neuro-oncology center in southern Germany has agreed to conduct a proof-of-principle human study for the device, the firm said.
Twenty patients already scheduled for brain tumour surgery will be selected and ten of them will be exposed to ultrasound in combination with a standard injection of chemotherapeutic drug, while the other half will receive only the intravenous drug.
After the tumours are removed, the concentration of drug in the tumour specimens will be compared in order to demonstrate that therapeutic concentrations of the drug are achieved in the area surrounding the tumour.
The study was carried out in collaboration with biotech company RxGen, which leverages highly predictive pre-clinical models of human disease to accelerate the drug development process.
