AMD Update 5: Emerging Technologies for Treating AMD
First, a summary of some of the newer technologies that I have been tracking and writing about:
The Ellex 2RT Retina Regeneration Therapy
Just prior to the 2007 AAO meeting, I became aware of a new potential laser treatment for retinal diseases. I met with the then president of the company, Peter Falzone, and decided to write about what Professor John Marshall and his colleague Dr. Ali Hussain were proposing.
From what I understand, 2RT is the use of non-thermal laser pulses to “stimulate” the retinal pigment epithelial (RPE) cells. This in turn causes the RPE cells to migrate and release metalloproteinases, which are the enzymes that “clean” Bruch’s membrane. This, in turn increases the transport of water and chemicals through Bruchs to rejuvinate the retina.
For more on this, see my writeup: Ellex 2RT Retina Regeneration Therapy: A First Report
Collaboration Between Lumenis and Stemedica
In May of 2008, I became aware of the collaboration agreement between Lumenis and Stemedica, to use the Lumenis SRT laser to target RPE cells (similar to what John Marshall, above, was doing in London), and then to use Stemedica’s stem cell lines to regenerate the damaged retinal cells.
I contacted friends at Lumenis and the people at Stemedica, offering to write up what they were trying to do, and compare it with what John Marshall in London was doing.
Unfortunately, my friends at Lumenis were no longer with the company, and no-one at Stemedica was willing to talk to me.
Recently, a new-found friend at Lumenis informed me that the Lumenis SRT laser was no longer in the picture and that Stemedica was continuing on its own. I then got an offer from a researcher at Stemedica to tell me what they were doing, but upon followup, no further information was forthcoming. (I do know, however, that research on the project is continuing and being carried out at the Fyodorov Eye Institute in Russia.)
Also, one of my old friends from Lumenis, the former program manager, got in touch with me and said he was interested in pursuing the Lumenis SRT development project if he could obtain outside financing. So, this approach is still alive and ticking.
Visualization of Living RPE Cells
In February of this year, David Williams and his research group at the Institute of Optics at the University of Rochester announced that they had used adaptive optics to image RPE cells in vivo.
I have written up this announcement in more detail: AMD Update 4: Does Visualizing RPE Cells Hold the Key to Understanding AMD?
Now we have a diagnostic mechanism to see changes in RPE cells, possibly when applying some of the new techniques discussed above and below.
And, now, the breakthrough that could hold the key to finally finding a “cure” for AMD:
Embryonic Stem Cell Treatment for AMD
Finally, as noted above, I came across an article that appeared in the April 19, 2009 issue of the London Times Online, describing the work of Professor Peter Coffey of the London Project to Cure Blindness and Dr. Lyndon da Cruz, a surgeon at Moorfields Eye Hospital in London.
Their process involves replacing a layer of degenerated retinal cells with new ones, created from embryonic stem cells, pioneered by scientists and surgeons from the Institute of Ophthalmology at University College London and Moorfields Eye Hospital. Further, Pfizer has announced one of its new companies, Pfizer Regenerative Medicine, launched last year, will be providing financial backing of this project to bring the therapy to fruition. The undifferentiated embryonic stem cells will be transformed into differentiated replicas of the degenerated RPE cells, placed on a membrane and inserted into the back of the retina.
Professor Coffey believes that the insertion process could be accomplished in less than an hour, making this a potential outpatient process.
A clinical trial is expected to begin within two years and become the second in the world to use embryonic stem cells in humans. (The first being the work by Geron on patients with spinal cord injuries.)
This technology could become ground-breaking breakthrough technology in the treatment of dry AMD and Geographical Atrophy.
In their own words, here is how The London Project to Cure Blindness describes their process:
“Neuralised human embryonic stem cells (HESCs) represent a potentially unlimited source of progenitor cells for use in the repair of retinal disease. In addition to the genesis of retinal neurons, there is now compelling evidence that RPE can also be derived from undifferentiated HESCs. These ES-derived RPE cells not only appear to behave like normal RPE in culture but also have a gene expression profile more akin to primary human RPE. This is of particular clinical relevance to any RPE based transplantation strategies designed to treat AMD.”
“HESCs will be used to generate precursors of retinal pigment epithelium (RPE) cells in vitro in order to provide a candidate therapeutic for age related macular degeneration (ARMD). The previously used method will be optimized with respect to RPE cells to improve both yield and reproducibility. RPE transplantation has already been shown to be capable of restoring the subretinal anatomy and improving photoreceptor function in a variety of retinal diseases. The sourcing of appropriate cell lines with the prerequisite characteristics of RPE will allow transplantation to enter the mainstream of retinal therapy at a time when the treatment of previously blinding retinal diseases is finally becoming a reality.”
Pfizer Regenerative Medicine’s role will be to focus on clinical study design, product manufacturing (the membrane), and securing worldwide regulatory approvals.
Under the terms of the collaborative agreement, Pfizer will fund University College London's preclinical research. In turn, Pfizer will retain exclusive worldwide rights to proceed with efficacy trials to develop and commercialize any resulting retinal pigment epithelium stem cell-based therapies.
"We are excited to be working with pioneers in the field of stem cell ophthalmology from UCL," Ruth McKernan, PhD, chief scientific officer for Pfizer Regenerative Medicine, said. "While we have much to learn about how stem cells can be used therapeutically, we are confident that this relationship will increase that understanding and help us advance to a time when our work may benefit patients worldwide."