Of course I would love to say emphatically YES, but there are still challenges and obstacles in the way. With that said however we are closer than ever, the advances in finding a cure to inherited retinal diseases has grown exponentially in the past 5-10 years.
We recently attended a presentation at the Carroll Center for the Blind which was part of
the Boston Chapters Speaker Series Presentations that are sponsored by the Foundation Fighting Blindness (FFB). This particular series was of interest to us because one of the presenters was Dr Eric A Pierce, MD, Ph.D who is the Director at the Ocular Genomics Institute, Associate Director at the Berman-Gund Laboratory for the Study of Inherited Retinal Degenerations, Lecturer at the Department of Ophthalmology for Massachusetts Eye and Ear infirmary and Harvard Medical School, and also one of Rebecca’s primary ophthalmologists. It was also a discussion about the state of treatments for degenerative retinal diseases of which retinitis pigmentosa (RP) is.
We first met Dr Pierce (Dr Pierce Bio) when we learned about Rebecca’s diagnosis of Usher Syndrome, and after over an hour long discussion about her diagnosis Dr Pierce had us leaving his office feeling optimistic. As Dr Pierce explained, a few years prior to our visit he would have been cautious about telling us that there was hope of maintaining or restoring Rebecca’s vision but he was now to be able to tell us that the research that was being performed in fact could very likely lead to a treatment for her in as little as the next 5-10 years. Much of the work over the past 30 years by the FFB and other foundations is beginning to solidify and resulting in a better understanding of the diseases associated with retinal degeneration and ultimately the cures for them. This is why we are focusing on raising funds for the FFB (foundation fighting blindness) so that this work can continue.
The presentation was a Q/A style with Martha Steele asking the questions. Martha Steele is the Boston Chapter President and Vision Walk Chair. I spent a bit of time talking with Martha after the event, she has Usher 2B I believe (hope i did not get that wrong) and has impaired vision.
Martha started by asking Dr Pierce to explain the structure of the retina to which Dr Pierce explained that the retina is a light sensitive tissue lining the back of the eye, much like the CCD chip in modern cameras. The retina is not a single layer in fact it is made up of 10+ complex cell structures of which two of them are rods and cones. Rods are responsible for low light vision and cones are responsible for color vision and work best in brighter light. Retinitis pigmentosa affects the rods first and why we are seeing degradation of Rebecca’s night vision even in these early stages of her life.
Next Martha asked about the types of treatments available today. Before Dr. Pierce proceeded he gave a brief laymen view of the human genome. He compared the human genome to a library of books with a rough total of twenty thousand books. Each book having thousands of chapters with millions of words in the collective library. In the case of an inherited retinal degenerative disease the words within these chapters are misspelled and ultimately change the meaning of the chapter resulting in the mutation, so even before a treatment is considered in many cases it is more important to find the misspelling. With the mind numbing amount of data that is present in the human genome the challenge to find the misspelling is no small task and in many cases technology is still not advanced enough to understand all misspellings related to all diseases. In the case of RP 1B the misspellings are better understood so some of the therapies can target the misspelled gene and correct it.
Dr. Pierce went on to explain the three main treatment areas:
He outlined two types of pharmaceuticals small molecule drugs that are packaged in a pill and biologics which are genetically engineered proteins.
These drugs are neuro-protective agents and are essentially used to try to keep the photo receptors within the retina happy such to slow down the progression of the disease. There are many forms of these drugs, vitamin A has shown some promising results however in a small population of people. Proteins are also being used and showed limited benefit.
Second was Gene Therapy
Unlike neuro-protective agents of which the hope is to prolong vision, gene therapy not only aims to slow progression but also has the potential to reverse vision loss as it is essentially replacing the misspelled genes. With gene therapy the identification of the misspelled gene is typically needed before treatments, but once identified, an attempt is made to replace the bad gene. Not too long ago this was science fiction but today researchers have figured out that they can use viruses to deliver these good genes. The challenge was identifying viruses large enough to carry many of the genes, in the case of Usher Syndrome 1B the genes are small enough to be carried by some of the more common viruses used in gene editing. Spark Therapeutics out of Philadelphia is in late stage testing and working on approvals for commercializing gene therapy drugs to be used in retinal degeneration. This is very exciting as it has the potential to open the flood gates for others to follow suit. We need pioneers to clear the path in this area and this company is close to being the first to deliver a gene therapy to market and can really change the landscape for other companies that are gearing up to do the same. We will be keeping close tabs on the progress of this company and hoping for their success.
And the Last was Stem Cell Therapy
Stem cell therapy is also being researched, this is likely a good candidate when the misspelling can not be identified and rather than trying to fix the genes the cells themselves are either manufactured or manipulated. Optogenetics, which is a form of stem cell therapy, essentially creates light sensitive cells in the retina. At this time however it is unclear how the light sensitive cells will translate this stimulus into images. Optogenetics and the prosthetic eye (second sight) are essentially performing the same function. Although Stem cells are another exciting area being researched I personally worry about the potential finality of the treatment and the inability to reverse any negative affects. Although this is an exciting area it sounds like it is in its very early stages.
Martha went on to ask Dr Pierce about each of the treatments with respect to when they should be considered relative to the stages of vision loss. As expected Dr. Pierce answered that it truly depends on the individual, the decision needs to be approached from a risk vs reward perspective. Any of these treatments have the potential to increase the rate of degradation of residual sight and that needs to weigh heavily on the patients decision. In Rebecca’s case she is able to see today and her vision will degrade slowly over time so of course the risk of treatment needs to be next to zero for it to even be considered. We are hopeful that the decision will not need to happen until she is mature enough to help make it, and of course that the risk is dramatically reduced.
Dr. Pierce ended the Q/A after about 35 minutes of speaking with the following thought… He said that we should be hopeful but we are running a marathon and although he sees a treatment in our future there are still many miles to go before a cure is realized.
At this point Dr. Pierce took questions from the audience and the one that I will capture are his thoughts on the challenges that we still face in our fight to find a cure. Most of the other questions were very specific to certain retinal diseases.
As far as challenges go, Dr. Pierce emphasized that there are many trials going on and some will fail, many more will fail than succeed in fact, and we need to figure out how to maintain momentum. We are learning from each trial and that can not be viewed as a failure. This really resonated with me and further solidifies how important raising awareness is. We need to continue to let the world know how close we are to a cure and not allow setbacks to discourage efforts to move research forward.
Another challenge we face is how do we know if a treatment works. It literally could take decades to see benefits from a treatment and this could also result in a loss of momentum.
I do feel optimistic that there will be a cure before Rebecca loses her sight. It’s still a cautious optimism however, and we will still prepare her for blindness in any way we can, but I am optimistic nonetheless. We will of course continue to raise awareness and funds as our part in helping to to keep momentum and to ultimately find a cure for her.