 |
| Current clinical trials are evaluating stem cell therapies for conditions ranging from eye disease to AIDS. |
Discoveries
in stem cell science over the past decade are finally starting to reach the
clinic. Current clinical trials are evaluating stem cell therapies for
conditions ranging from eye disease to AIDS.
These
trials are going on in the United States, Europe, Canada, Japan and elsewhere.
But Australia is lagging behind. While we remain fairly competitive in
fundamental research, we are slow to translate our discoveries into new
therapies.
This
concern was expressed in the Australian Academy of Science report, released
today, called The Stem Cell Revolution: Lessons and Imperatives for
Australia. It contains a series of recommendations from young
research leaders in the field on how Australian science policy can help
fast-track stem cell research here.
Researchers
are often asked by patients or their relatives when stem cell treatments will
be available for certain medical conditions. Ten years ago, the answer would
have been that there are no new treatments yet, but we are working to develop
them. Today, we are forced to answer that clinical trials of cell therapies for
particular conditions are going on, but not in Australia.
We
have an obligation to ensure that Australian patients, their families, carers
and physicians are not left behind in the stem cell revolution.
Stem
cell therapy
Human
embryonic stem cells, which can become cells in any tissue of the body, were
first discovered in 1998. Today, embryonic stem cell treatment trials are
underway for macular degeneration (a common form of blindness), spinal cord
injury, juvenile diabetes and heart failure.
 |
| Embryonic stem cell therapies are being trialled for macular degeneration, a common form of blindness. |
Embryonic
stem cell therapies are being trialled for macular degeneration, a common form
of blindness.
Then
there are the induced pluripotent stem (iPS) cells that
Japanese scientist Shinya Yamanaka discovered, which won him the Nobel Prize in
2012. iPS cells are made from adult tissues and have many of the defining
properties of embryonic stem cells. They can be made from skin or blood cells
of any person.
After
Yamanaka’s discovery, Japan’s cell therapy regulatory framework was modified to
fast-track products from these new stem cells into the clinic. As a consequence,
therapies using induced iPS cells, which enable close tissue matching of stem
cell transplants to patients to prevent graft rejection, are now in clinical
trials there, only ten years after their discovery.
More
trials will begin very soon. For instance, years of research on midbrain
dopaminergic neurons, the cells lost in Parkinson’s disease, has paved the way
for upcoming trials of stem cells replacing these lost neurons.
There
are also a large number of human trials in progress using mesenchymal stem
cells, which are extracted from bone marrow, fat or other tissues. Capable of
modulating the immune system and inflammatory response, these stem cells have
the potential ability to treat arthritis, autoimmune disorders, graft versus
host disease in bone marrow transplant patients, and a number of other
conditions.
Neural
stem cells derived from either foetal or adult brain tissue are also undergoing
testing in humans, for rare inherited disorders of the brain or more common
conditions including spinal cord injury.
It’s
unlikely these early stage trials will produce cures for any of these
conditions. Indeed they might pose as many questions as they answer. But it is
essential and significant that these trials are moving forward, because the
lessons we learn from them will guide us towards the design of the next
generation of cellular therapeutics.
Gene
therapy and drug discovery
Today,
genetic modification of stem cells with precision can provide cell therapies
that can permanently correct serious genetic disorders.
 |
| Human embryonic stem cells can become cells in tissue in any part of the body. |
For
years, progress in gene therapy was almost totally blocked by safety concerns
around the relatively crude technologies for introducing genetic alterations
into patient cells. But technological advances have enabled precise correction
of genetic defects within a cell. This avoids off-target modifications that can
cause cancers and other serious toxicities.
New
treatments using combined gene and cell therapy are undergoing trials now. The California Institute of Regenerative Medicine
lists about ten new human studies, including in AIDS, blood diseases and
cancer.
Then
there is a third stream of stem cell research that, although perhaps less
visible to the general public, has implications well beyond cell therapy.
This
is the ability to derive pluripotent stem cells from patients with genetic
predisposition to disease, or to introduce disease mutations into stem cells
via gene editing. We can then use these disease-specific stem cell lines to
generate the cell types affected in a particular disorder to study what goes
wrong with them in the lab.
For
instance, we can study how a gene that causes epilepsy affects the electrical
properties of human nerve cells. Once we develop these cell culture models, we
can use them to screen candidate drugs to correct the deficits in the affected
cells.
This
technology will enable us to reduce dependence on animal models, which don’t
always replicate human diseases, and will reduce the risk of testing drugs on
living human subjects.
These
advances have the potential to speed the discovery of new medicines, to rapidly
eliminate candidate drugs that might cause toxicity in the clinic, and to save
millions from the costs of drug development.
To
ensure Australian patients have timely access to new stem cell therapies for
intractable diseases, we must maintain our excellence in fundamental stem cell
research. But we also need to develop new and better mechanisms to support
collaboration between academia, the private sector and philanthropists with the
aim of translating discoveries into cures.
https://theconversation.com/stem-cell-therapies-are-advancing-but-will-australian-patients-be-left-behind-56504
No comments:
Post a Comment