Bayer Presents Positive Phase II Data With Florbetaben Potential To Visualize Beta-Amyloid Plaques In Patients With Alzheimer's Disease

Bayer Schering Pharma
AG, Germany, has presented positive data on a global Phase II study with
the novel positron emission tomography (PET) tracer florbetaben (BAY
94-9172) at the International Conference on Alzheimer's Disease (ICAD) in
Vienna, Austria. This study showed that patients with a clinical diagnosis
of Alzheimer??s disease could be differentiated from age-matched healthy
volunteers (HVs) on the basis of florbetaben uptake pattern in the brain.



Until now, the clinical diagnosis of Alzheimer??s disease (AD) with current
methods such as cognitive tests is still limited. Currently, a definite
diagnosis of Alzheimer??s disease is only possible post mortem. The results
of this study showed PET images with a high specificity of over 90 percent:
More than 90 percent of the HVs had a negative florbetaben scan (i.e. no
tracer uptake) in the relevant brain regions. The results also show a
sensitivity of approximately 80 percent indicated by the clinical
diagnosis, meaning that about 80 percent of the clinically suspected
Alzheimer patients had positive florbetaben scans indicating the presence
of beta-Amyloid plaques. This is in line with the results of studies
comparing the clinical diagnosis with the definite post mortem
histopathological diagnosis.



"The data underline the potential of florbetaben as an important visual
adjunct to existing clinical parameters in the diagnosis of dementia," said
Kemal Malik, MD, member of the Board of Management and Head of Global
Development at Bayer Schering Pharma AG. "There is a high medical need for
an easy, non-invasive imaging technique that supports an early and precise
diagnosis of dementia and especially of Alzheimer's disease, allowing for
optimized care and treatment options." With the development of florbetaben,
Bayer Schering Pharma wants to contribute to diagnose AD in the future more
precisely and at an earlier time during the course of the disease.



In the blinded read of the images a high interreader agreement rate between
three independent readers was observed. This indicates that the scans with
the beta-Amyloid targeted PET tracer florbetaben are easy to visually
assess and that this assessment is highly reproducible.



Additional Phase II and pivotal Phase III global studies are under
preparation to validate the potential shown by florbetaben in this Phase II
setting. Start of the Phase III program is planned for end of 2009.



About the Phase II Study


This global Phase II, open-label, non randomized, multi-center study aims
to evaluate the efficacy of florbetaben PET in vivo imaging in the
detection/exclusion of cerebral beta-Amyloid plaques in patients with
mild-to-moderate, probable AD (older than 55 years of age) compared with
age-matched healthy volunteers. A total of 18 study centers in four
countries (Australia, Germany, USA, and Switzerland) screened 213
individuals of whom 150 individuals were imaged with florbetaben receiving
a single intravenous injection of the tracer. Reliable, high-quality images
were obtained across multiple centers and camera types over a long time
span. A 20-minute scan in this study provided optimal image quality.
















The florbetaben uptake pattern was visually assessed for all time points by
three independent, nuclear medicine physicians blinded to the clinical
diagnosis and all other clinical data.



The co-primary efficacy variables were the sensitivity and specificity of
the independent, blinded visual assessment of the images. As a secondary
endpoint, the standard uptake value ratios (SUVRs) were also calculated
using the cerebellar cortex as a reference region. The clinical diagnosis
of AD served as the standard of truth, and was performed by the referring
clinicians and based on internationally accepted and validated clinical
criteria. The HVs were also carefully examined to include only those with a
total lack of cognitive impairment. In addition, safety parameters were
evaluated and various technical parameters assessed to define the optimal
imaging procedure for further development (e.g. optimal imaging time
points).



About Florbetaben (18 F)


Florbetaben is an inlicensed 18F-labeled PET tracer that specifically binds
to beta-Amyloid plaques. These plaques consist of proteins that accumulate
in the brain and are a pathological hallmark of Alzheimer's disease. As the
aggregation of the beta-Amyloid protein in the brain is also a key target
for new therapeutic treatments under development, florbetaben might also be
able to support the development of these new treatment approaches.



About Alzheimer's Disease


Alzheimer's disease (AD) is a devastating neuro-degenerative disease and
the most common cause of dementia. Most cases of Alzheimer's disease affect
people over the age of 60. It is a progressive disease that can lead to
premature death. In 2006, estimates suggested that more than 26 million
people worldwide were suffering from Alzheimer's disease. By 2050, this
number could reach more than 100 million. At present there is no cure for
Alzheimer's disease, but treatments for symptoms, combined with the right
services and support, can make life better for the millions of people
living with Alzheimer's.



Source
Bayer HealthCare