Cardiovascular Journal of Africa: Vol 26 No 6 (November/December 2015)

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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 26, No 6, November/December 2015 250 AFRICA
Drug Trends in Cardiology
Encapsulated beta-cell replacement therapy for type 1 diabetes
Beta-cell encapsulation therapy is a
procedure that involves implantation of
cells, contained in a protective barrier,
with the ability to secrete insulin into the
body in a glucose-responsive manner.
On 17 July 2014, the Juvenile Diabetes
Research Foundation (JDRF) announced
that its partner, ViaCyte, Inc, had filed
an Investigational New Drug (IND)
application with the US Food and
Drug Administration (FDA), seeking to
conduct a phase 1 and 2 clinical trial in
patients with type 1 diabetes. The purpose
of this trial is to evaluate the safety and
efficacy of the VC-01 product, a stem cell-
derived, encapsulated-cell replacement
therapy. In addition to the IND, ViaCyte
also submitted a medical device master
file (MAF) to the FDA regarding the
Encaptra® drug-delivery system, a device
component of the VC-01 product.
Beta-cell encapsulation therapy is a
procedure that involves implantation in
a protective barrier of cells with the
ability to secrete insulin into the body
in a glucose-responsive manner. The
advantage of these encapsulated beta-
cells is that they can assess the patient’s
blood glucose level and secrete the correct
amount of insulin, while their barrier
protects them from being destroyed by the
autoimmune system. More importantly,
encapsulation therapy also helps prevent
the requirement of lifetime administration
of powerful and toxic immunosuppressive
drugs designed to protect the newly
introduced islets from the immune system.
VC-01 therapy is the combination of
PEC-01 cells (a proprietary pancreatic
endoderm cell product derived
through directed differentiation of an
inexhaustible human embryonic stem cell)
and an Encaptra drug-delivery system
(a proprietary immune-protecting and
retrievable encapsulation medical device.)
The VC-01 combination product is
expected to be implanted under the skin
of the patient through a simple out-patient
surgical procedure. Once inside the body,
the cells are expected to differentiate and
become mature pancreatic cells with the
ability to produce and secrete insulin
based on the patient’s glucose level.
Based on pre-clinical studies, VC-01
therapy has been shown to be effective
in mice. Normal blood glucose levels
for mice range from 160–200 mg/dl
(8.88–11.1 mmol/l) , which are considered
hyperglycaemic in humans. However,
when the mice received the VC-01
combination product, their blood glucose
levels were closer to human levels. In
addition, when these mice received STZ,
a chemical designed to kill native mouse
beta-cells, the mice still maintained their
blood glucose levels.
Study of the synergy of cell therapy
and the Encaptra medical device also
showed positive results. In the mouse
study, host blood vessels began to grow
into the VC-01 combination product at
week four, supplying a steady amount
of oxygen and nutrients to PEC-01 cells.
At week eight, vascularisation developed
quickly. Meanwhile, the Encaptra device
protected the PEC-01 cells from immune
rejection with a protective permeable
membrane.
The VC-01 cell replacement therapy
could be a potential cure for type 1
diabetes.
Reference
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27&catid=1&Itemid=17.
Blood glucose levels during acute illness can help predict future
diabetes risk
Blood glucose levels measured in
hospitalised patients during acute illness
predicted the risk of developing type
2 diabetes in the following three years,
according to a study published in PLos
Medicine in August 2014.
Scottish researchers measured the
blood glucose levels of 86 634 patients,
aged 40 years or older, admitted for an
acute illness between 2004 and 2008.
Patients were followed up to December
2011 to determine their type 2 diabetes
risk.
The researchers reported that type 2
diabetes risk for patients with a glucose
level of less than 90 mg/dl (5 mmol/l)
was 1% and the risk increased to
approximately 15% among those with a
glucose level of 270 mg/dl (15 mmol/l) or
more. Plus, the risk of developing diabetes
increased with increasing blood glucose
levels during admission.
Based on the findings, the researchers
developed a risk calculator that uses
the patient’s age, gender and admission
blood glucose level to predict risk of
developing diabetes over three years
following hospital admission. However,
the risk calculator has not yet been tested
in non-white populations or populations
outside of Scotland.
The researchers said in a press release,
‘These findings can be used to inform
individual patients of their long-term risk
of type 2 diabetes and to offer lifestyle
advice as appropriate.’
Reference
php?option=com_content&view=article&id=167
90&catid=1&Itemid=17.