The drug, known as PBT2, counteracts the production and build-up of a protein called amyloid-beta that occurs in Alzheimer's disease. This protein, which can build up into a ‘plaque’, is believed to be toxic to brain cells and to prevent them from functioning properly.
Seventy-eight participants with early stage Alzheimer's disease took either 50mg or 250mg doses of the drug PBT2, or a placebo, over the course of 12 weeks in a randomised, double-blind clinical trial, led by a researcher from Imperial College London working with colleagues in Australia and Sweden. Both doses of PBT2 capsules were observed to be safe and well tolerated during the course of the study.
Participants undertook a number of tests to assess their cognitive function, prior to beginning treatment and at the end of the 12-week period. In two of these tests of executive function, which involves the ability to organise information, sequence events and plan, those on a 250mg dose of PBT2 showed a significant improvement over the placebo group.
The researchers also measured how the levels of amyloid-beta in spinal fluid changed during the course of the trial. They found that levels of amyloid-beta 42 in the cerebrospinal fluid of those on the 250mg dose of PBT2 were reduced by approximately 13 percent compared to placebo at the end of the 12-week period.
Amyloid-beta needs the metals zinc and copper in order to accumulate in the brain and these two metals become abnormally distributed in the brains of people with Alzheimer's disease. PBT2 works by interrupting the interaction between the metal ions and amyloid-beta, and returns levels of zinc and copper in the brain to normal levels.
In the cognitive tests, those on a 250mg dose of PBT2 were able to complete the task in a test known as Trail Making Part B an average of 42 seconds faster than they had at the beginning of the trial. The placebo group was an average of 6 seconds slower.
In the Category Fluency Test, which looks at a person's ability to come up with as many relevant words as possible in relation to a specified category, those in the 250mg group were able to produce an average of 2.4 more words than at the beginning of the trial. This compared with a decrease of 0.3 words in the placebo group.
Although memory loss is the problem most often associated with Alzheimer's disease, the executive cognitive functions assessed by these two tests typically begin to deteriorate in the early stages of the disease, though are sometimes less obvious than memory symptoms.
There were no significant differences in participants' scores on tests assessing their memory function in the new study, but the researchers believe this may be because the memory function deteriorates at a slower rate than the executive functions at this stage of illness, making changes harder to detect in a short study.
Dr Craig Ritchie, from the Division of Neurosciences and Mental Health at Imperial College London, who led the study, said: "Alzheimer's disease is a devastating condition and it affects hundreds of thousands of people in the UK. The results of our trial are very encouraging, although it was a relatively small study, which took place over a short period of time. Our findings certainly engender much optimism that this drug may have a significant effect on the underlying pathology of Alzheimer's, with a tangible clinical benefit for patients.
"We now need further research to see how PBT2 performs in larger, longer-term trials. Our hope is that we might be able to see treatments that can substantially improve the lives of people with early Alzheimer's disease within the next five or so years," added Dr Ritchie, who has been assisting the Australian company Prana Biotechnology with the clinical development of its new drugs for ten years.
The next step for the research is to move forward with PBT2 in further trials with a view to gaining a license for the drug.
These study results follow on from a recently published study of mice which showed that PBT2, in the space of a few days, cleared amyloid-beta, improved cognition and reduced the damage to brain cells. The parent compound to PBT2, clioquinol, was shown in a small study of 36 patients in 2003 to slow the progression of Alzheimer’s disease. PBT2 was developed to be even more effective than clioquinol at attacking the core pathology of the disease.
Laura Gallagher | alfa
Biofilm discovery suggests new way to prevent dangerous infections
23.05.2017 | University of Texas at Austin
Another reason to exercise: Burning bone fat -- a key to better bone health
19.05.2017 | University of North Carolina Health Care
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
29.05.2017 | Earth Sciences
29.05.2017 | Life Sciences
29.05.2017 | Physics and Astronomy