Byron Lam, MD, an Ophthalmologist at Bascom Palmer Eye Institute talks about Luxturna, how it works, and how it helps patients.
Interview conducted by Ivanhoe Broadcast News in December 2018.
What we’re talking about is very exciting. Talk about the actual condition, are we talking about something that’s very rare and what is it?
Dr. Lam: Leber Congenital Amaurosis is a congenital retinal degeneration. Patients are born with it and the vision is significantly decreased during the first years of life. Patients with this disorder have decreased central vision and night vision. Their symptoms are quite overwhelming In most cases. This is a rare condition, and the prevalence is approximately one in eighty thousand. The new treatment, LUXTURNA, is a treatment that aims at ten percent of the patients with Leber congenital amaurosis who has particular genetic change on a gene called RPE65.
So only a percentage of those patients with this condition have the mutation that would be helped by this treatment?
Dr: Lam: Yes. Only a portion of the patients with Leber congenital amaurosis has the treatable RPE65 condition. The reason this treatment was developed is because of several important factors. There was a natural occurring dog model that just happened to carry the same type of genetic problem as humans and this facilitated the testing of the effectiveness of the treatment.
And patients with this condition they’re born with it and it just progressively get worse over time until they’re completely blind?
Dr. Lam: The condition is gradually progressive. Patients are born with poor vision most of the time and of course entering the first couple of years their vision is noted to be very poor and then over time the vision deteriorates. By the time in the mid twenties or early thirties, the vision is very poor. It can lead to perhaps light perception vision and in some cases no light perception vision by the time that the patient is in the fifties.
So really before this there was nothing that could treat or cure these patients?
Dr. Lam: Correct. This is considered a disorder that has been identified for a couple of decades and there was no established treatment at all.
So basically they would prepare and possibly live the rest of their lives blind?
Dr. Lam: What happens when we didn’t have the treatment, patients had very poor vision early on in their life, and this not only affects their regular day-to-day function but it also affects their education. They lose many of what we take for granted. A good education, a good interaction with other people. Of course, as their vision deteriorates this clearly affects their life further.
This gene therapy is called LUXTURNA and how does that work?
Dr. Lam: The treatment is called LUXTERNA and it is a gene therapy. A normal RPE65 gene is placed on a viral vector. Of course people may say: “Oh, a viral vector. I’m going to get infected.” But the viral vector is deactivated so the gene RPE65 is placed on to the virus with its own genes are removed. The deactivated virus that carries the normal gene goes into the photoreceptor cells and other cells in the retina including the retinal pigment epithelial cells and restores the function.
Are you replacing it with the right gene or the non-mutated gene?
Dr. Lam: What happened is the patient’s own gene RPE65 is defective and a normal natural copy of the RPE65 gene is delivered to the cells on the retina. The cells have the defective gene and weren’t functioning properly. Now they have the normal gene and the normal gene produces normal RPE65 and then the retinal starts to function normally.
How soon after the procedure can this all take place? Or do they start to see some improvement with vision?
Dr. Lam: The younger patients, because their retina structure is fairly well intact and they are very early in their condition, have the most to benefit from this treatment. Typically even one month later you can see significant improvement in their vision and in their function.
And is it the hope that will continue and actually stop the progression of the retinal being damaged over time, saving these people’s site?
Dr. Lam: Correct. A couple goals. one important therapeutic effect is to improve the vision. Another one in perhaps patients who are more advanced, the vision may not improve, but your goal is to keep the vision and maintain the vision so it does not get worse. At current knowledge, we have three years of follow up in treated patients, and we know that at least for three years the visual function is maintained with the treatment. However, with more time in terms of learning about the maintenance I think we’ll have more data about how long the vision can be maintained.
So far you have three cases, and you’re saying the older one which was thirty seven may not see as much improvement as the younger patients?
Dr. Lam: We have treated actually six patients so far at this point in time. The younger patients, the patients who are in their teenage years or in their first decade of life, definitely respond better to the treatment which is what we expect.
Getting this diagnosis early is critical.
Dr. Lam: Correct. I think making the diagnosis earlier is critical and of course referring the patient properly to an inherited retinal disease expert is also critical.
How expensive is this procedure and is it covered by insurance?
Dr. Lam: Treatment is $425,000 per eye for the therapeutic agent. With the surgery and treating both eyes, you’re talking about treatments that’s nearly $900,000. This treatment is expensive and is paid by insurance.
The patient must have insurance authorization and of course the debate is it’s so expensive is it a worthwhile treatment? But what I can say as a treating physician when you see the remarkable improvement in the patients is that it changes their entire life. In my mind I think it’s very well worth it. Society of course will need to decide whether this cost is worth the gain.
Tell us the price again.
Dr. Lam: It’s $425,000 for the therapeutic agent per eye. If you go ahead and add the treatment including the surgeries and also including both eyes, you’re talking nearly $900,000 total for the treatment.
You said you only have data three years out and you don’t know where people would be beyond that, is this a treatment that could possibly be repeated or as life goes on or is it a onetime deal?
Dr. Lam: Right now we do not have data on re-treatment on the same eye. And we really don’t know how the eye will react to a second treatment. That consideration will have to wait for the future.
But this definitely moves us forward as far as gene therapy is concerned in general. It’s taking us forward and it’s the first time the treatment has been available for this type of condition.
Dr. Lam: Sure, I would just say that this is like a dawn of an era for gene therapy. This is the first ocular gene therapy that has been approved. So clearly this opens the door for future therapies, it’s the first one and we still have a lot to learn. But the hope is that other patients who have other inherited retinal disorders will get treated in the future.
END OF INTERVIEW
This information is intended for additional research purposes only. It is not to be used as a prescription or advice from Ivanhoe Broadcast News, Inc. or any medical professional interviewed. Ivanhoe Broadcast News, Inc. assumes no responsibility for the depth or accuracy of physician statements. Procedures or medicines apply to different people and medical factors; always consult your physician on medical matters.
If you would like more information, please contact:
Kai Hill, PR University of Miami Miller School of Medicine
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