when I was an undergraduate student at University of
Illinois,” said Dr. Reh. “There was a professor there,
Dr. David Stocum, who studied limb regeneration in
these amphibians. I was fascinated that these animals
had this potential. When I started my own lab as
an assistant professor in Calgary, I began to study
regeneration in tadpoles.”
Dr. Reh’s paper in Nature highlighted his retinal
regeneration advancements in mice. His team was
able to derive neurons from retinal cells called MÜller
glia, which normally provide architectural support
and a number of protective and waste-disposal
functions. The new neurons connect with the existing
circuits and the cells respond to light. However, the
new neurons are not full-fledged photoreceptors, so
there is much more work to be done in advancing the
approach into a human study.
“The FFB is currently funding our research to derive
actual photoreceptors from MÜller glia,” said Dr. Reh.
“The next step would be to develop an appropriate
gene therapy for humans to direct expression of the
protein Ascl1, the catalyst for deriving photoreceptors
from MÜller glia.”
Dr. Reh added that safety and efficacy studies in
a large-animal model would be necessary before
moving the approach into a clinical trial. “While
more work needs to be done, Dr. Reh’s regenerative
therapy is potentially another achievable option
for retinal regeneration that has advantages over
transplantation,” said Stephen Rose, PhD, FFB’s chief
scientific officer. “He’s an innovator willing to look
outside of the box. That is important in getting vision-restoring, retinal-disease treatments out to the people
who need them.”
Refillable Capsule Performs Well for Reducing
Treatment Injections for Wet AMD
For many people with wet age-related macular degeneration (AMD), treatments like Lucentis® (ranibizumab)
can save and even restore vision. They work by stopping the growth of leaky blood vessels that cause
degeneration of photoreceptors and central vision loss.
However, these therapies require regular injections into the eye at an ophthalmologist’s office. The regimen can
be prescribed as often as monthly or at least several times a year.
Genentech’s Port Delivery System (PDS) — a tiny, refillable capsule, slightly longer than a grain of rice — was
developed to reduce the treatment burden by continuously delivering a special formulation of ranibizumab to
the retina. The PDS, which is surgically implanted into the eye, may enable people with wet AMD to go several
months before needing a refill.
For 59 PDS patients receiving the 100 mg/mL dose in a Phase II clinical trial, approximately 80 percent were able
to go six months or longer until their first refill was required. The PDS is refilled using a customized needle in a
minimally invasive office-based procedure.
Genentech is determining the most appropriate dose and treatment interval for its Phase III clinical trial for the
PDS. Companies seek FDA approval for treatments if they perform well in Phase III.
“While current wet AMD therapies often work for patients, they require regular eye injections and visits to the
eye doctor. Getting treatment can be burdensome, especially for elderly patients,” says Stephen Rose, PhD, chief
scientific officer, Foundation Fighting Blindness. “The Port Delivery System shows promise for reducing this
inconvenience and helping ensure patients are getting the treatment they need to preserve their vision.”
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