january 2008
LCA Gene Therapy Clinical Trials Update
Remember when everyone was talking about those doctors who had found a way to "cure" LCA in dogs? We were all eagerly awaiting the clinical trials to begin in humans, but these things just seem to move so slowly! Well, we finally have some new news!
As you may have been following, the LCA gene therapy clinical trials were first approved in December of 2005. Before this approval, doctors had successfully used gene therapy to restore sight in dogs who were diagnosed with LCA. This was very promising and they were eager to try the same approach on a human model. You can read more about the approval and the dog trials here.
Nearly two years later, in October 2007, they were finally able to begin the first clinical trial on a human. That human, Billy, introduced himself to the LCA email group on December 20, 2007 and was gracious enough to accept our bombardment of questions. Below are our questions and Billy's answers...
Tell us a little about yourself.
My name is Billy and I'm from Spartanburg, South Carolina which is in the northern part of SC. I am currently going to school for a B.A. in Computer Science. I have worked in 911 communications services as I.T. Director and Telecommunicator. I am turning 25 tomorrow.
How long has it been since you received treatment in the trial?
I received it on October 18, 2007 at about 9:30 am.
Can you describe your vision before the trial began? Did you see better as a child? Has your vision gotten worse as you've gotten older?
Before the trial I could see well enough to read size 12 font in high contrast on the computer. I am one of the rare few who have had pretty good eyes from birth on. I can see well enough to do most things except drive. I could almost drive just not legally.
Why are they choosing patients with so much usable vision? Could patients with less vision still be helped by the therapy?
See, the damage is done in LCA early on and the gene transfer will still fix the genetic problem but not regrow cells, BUT the next part of it will be fixed with stem cells.
Are you experiencing any changes in vision yet?
Yes, in a sense. I do now have brighter flashes of light in that eye that I did not have before. I can see 20/200 in my right eye. They did the surgery on the left. The visual acuity in the left eye actually dropped from 20/200 to 20/400. I was told this should be temporary. So some minor improvement in light could be considered as an improvement but the drop in acuity is not good.
Did you experience any pain? Have you had any adverse reactions at all?
Not really other than what I mentioned above.
I'm surprised to hear your vision actually decreased after you received gene therapy. You said they told you it would be temporary. So was that expected? Did they explain why?
Well, yes it did decline, but they still stand by the procedure right now. This trial is mainly for safety concerns. The reason for the decline is the way the injection takes place. I am going to explain exactly how it is done.
On Surgery Day they take you down to the OR and prep you early in the morning. They had me on IV fluid for use during the surgery. When I got ready for the surgery they moved me to the operating table and talked me through each thing they were doing. They put everything over my face needed for the procedure to be sterile. Next, they temporarily knocked me out and made the first incision into the eye which would be used to numb the eye and make it stable. They woke me back up and started sticking the other 2 needles in. 1 for pumping eye fluid in and out. This is done to keep eye pressure stable. The other needle is used for injecting the vector.
Now, when they go to inject the vector they make a small retina detachment. This is where the long term affects come in. If any of you care to look at retina detachments you will see that it takes quite a long time to heal. I can say they told me that it is only to affect 5-10% of my area of good vision.
Today I am noticing some more brightness.
The needles sound very scary. Did they have to stabilize your eyes? All I can think is that I would definitely blink!
It was not that scary. Yes, they did stabilize my eye. They put a sterile tape over my head with a little table over my face with only one hole for the eye having the procedure. I couldn't see out of the other eye because the table covered it. They numbed my eye and I barely felt anything except a little pressure from the needle, but not pain.
I just have a question about the retinal detachment. You were saying that the doctors said it would affect 5-10 percent of your vision? Does this mean that they meant you would loose that amount of your pre-trial vision due to the detachment temporarily or for good?
Well from what they told me I gathered that they meant if it went either way it would be about 10%. In order for them to inject the material they have to create a very small retinal detachment. I have brighter light levels now, but it is still blurry. I had vision enough to read large print out of this eye before surgery, but now I don't. I personally think it is a time issue right now. Just waiting and hopefully seeing better. I think I may have increased night vision more than anything.
How long did they say it would be until you reach full potential from the procedure?
Since this is the first time this has been done there are so many unknowns such as how long it may take for it to work or not work. Originally it was 4-6 weeks, but we have surpassed that.
Did you indeed stay in Florida for three weeks? Was it as boring as Dr. Jacobson promised?
Yes, it was pretty boring. I had to come up with ways to spend my time. I mainly sat and watched TV and played on the internet. Dr. Jacobson is very selective in the way he does things which is ok. I know he is very smart. I love talking to them. I loving learning what is going on and how these tests work. I have been very lucky to have a lot of this stuff explained to me. By far it was an interesting experience.
Is your treatment finished or is there more to go?
I will be heading to Philadelphia, PA to continue the checkups. No more actual treatment is necessary for me at this time. If it does work then I will do the right eye in the next year.
Do you know how many participants are in the trial?
Well, there is expected to be 8 or 9. No other person has had the procedure yet. I will have more details next Saturday when I return from Philly after having the checkups. They were expecting to do another before Christmas but I don't think that has happened. I have a friend who may be in it in March.
Are you glad you participated?
Yes, for the most part. I am doing this for the younger generation. If I gain it would be a big plus, but if not, oh well, I hope the kids of the future will.
We heard back from Billy in January 2008 after a recent trip to Philadelphia for a checkup with his doctors...
How was your latest checkup in December (2007)?
I spent the better part of Wednesday afternoon through Friday afternoon doing my usual tests which include FST and I dunno what all they are called. I arrived back home Saturday morning safe and sound. The results from the past 2 visits are that it appears there might be some POSITIVE growth of the cells in the retina. Still a little early though. The blurred vision I am experiencing could take 6 months to a year before it fully comes back. The reason for this is the cones have to re-grow. I am still seeing better in dim light in the operated eye.
Also, the 2nd participant has been operated on with no safety concerns. Because of confidentiality I am not able to find out more about that person.
I certainly don't want to compare you to a dog, but as most of us know, the original trials like this were in dogs. Do they know if you or the other participants appear to be going the same direction as that trial? Is it too early to tell, or are comparisons just not easily made between animal and human trials?
I think that it is a little difficult to compare but I believe it is taking humans a little bit longer to obtain the transfer. Also the dogs stayed in complete darkness and we humans just can't do that so they think light may slow the process.