Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gene therapy 1 year later: Patients healthy and maintain early visual improvement

14.08.2009
Phase I clinical trial for genetic eye disease also shows visual benefit for daily activities

Three young adults who received gene therapy for a blinding eye condition remained healthy and maintained previous visual gains one year later, according to an August online report in Human Gene Therapy. One patient also noticed a visual improvement that helped her perform daily tasks, which scientists describe in an Aug. 13 letter to the editor in the New England Journal of Medicine.

These findings have emerged from a phase I clinical trial supported by the National Eye Institute (NEI) at the National Institutes of Health, and conducted by researchers at the University of Pennsylvania, Philadelphia, and the University of Florida, Gainesville. This is the first study that reports the one-year safety and effectiveness of successful gene therapy for a form of Leber congenital amaurosis (LCA), a currently untreatable hereditary condition that causes severe vision loss and blindness in infants and children.

"These results are very significant because they represent one of the first steps toward the clinical use of gene therapy for an inherited form of blindness," said NEI director Paul A. Sieving, M.D., Ph.D. "I anticipate that it is only a matter of time before similar techniques will be applied to other genetic diseases affecting vision."

The three patients in the study—aged 22, 24 and 25—have been legally blind since birth due to a specific form of LCA caused by mutations in the RPE65 gene. The protein made by this gene is a crucial component of the visual cycle. The RPE65 protein is necessary for the production of a retina-specific form of vitamin A that is required for the light-sensitive photoreceptor cells to function. Mutations in the RPE65 gene prevent this production, which halts the visual cycle and blocks vision.

The RPE65 disease offers an opportunity for treatment in that it leaves some photoreceptors intact. In this study, researchers pinpointed an area of intact photoreceptors in the retina of each patient. They injected healthy copies of the RPE65 gene under the retina in this area in an attempt to repair the visual cycle.

One year after the procedure, the therapy had not provoked an immune response in the eye or in the body. Though the patients' visual acuity, or ability to read letters on an eye chart, remained unchanged, all three patients could detect very dim lights that they were unable to see prior to treatment. This visual benefit provides evidence that the newly introduced RPE65 gene is functional and is increasing the light sensitivity of the retina.

"These new reports extend our previous findings from three months after the procedure. At one year, we have now found that the RPE65 gene therapy appears to be safe and leads to a stable visual improvement in the patients studied. We are cautiously optimistic about these results and look forward to additional reports that address the key issues of safety and effectiveness," said Artur V. Cideciyan, Ph.D., research associate professor of ophthalmology at the University of Pennsylvania and lead author of the publications.

At 12 months, one patient also noticed that while riding in a car, she could read an illuminated clock on the dashboard for the first time in her life. When researchers performed additional visual testing, they found that this patient focused on images with a different part of the retina than they expected.

The fovea is the area of the retina where the sharpest central vision normally occurs. However, instead of focusing on images with the fovea, this patient had gradually begun to use the area of the retina that had been treated with gene therapy. The area had already become more light sensitive than her fovea at one month after treatment, but it took 12 months for her to read dim numerals—such as the illuminated clock—that she was previously unable to read.

"This interesting finding shows that over time, a person visually adapted to gene therapy in a meaningful way," said Samuel G. Jacobson, M.D., Ph.D., professor of ophthalmology at the University of Pennsylvania's Scheie Eye Institute and principal investigator of the clinical trial. "As we continue our studies, we will look more closely at whether these slow visual gains could be accelerated with visual training."

Researchers will continue to follow these patients over the next several years to monitor safety and to learn whether the visual benefits remain. This ongoing phase I trial also includes additional groups of LCA patients—children as well as adults—who are receiving different doses of the RPE65 gene therapy.

For additional information about LCA, visit www.nei.nih.gov/lca. Find more information about this trial (NCT 00481546) at www.clinicaltrials.gov.

References:

Cideciyan AV, Hauswirth WW, Aleman TS, Kaushal S, Schwartz SB, Boye SL, Windsor EAM, Conlon TJ, Sumaroka A, Pang J, Roman AJ, Byrne BJ, Jacobson SG. (2009) Human RPE65 Gene Therapy for Leber Congenital Amaurosis: Persistence of Early Visual Improvements and Safety at 1 Year. Human Gene Therapy, vol. 20, no. 9; published online August 2009, ahead of print (doi: 10.1089/hum.2009.086).

Cideciyan AV, Hauswirth WW, Aleman TS, et al. Vision 1 Year after Gene Therapy for Leber's Congenital Amaurosis. N Engl J Med 2009; 361:725-727.

The National Eye Institute (NEI), part of the National Institutes of Health, leads the federal government's research on the visual system and eye diseases. NEI supports basic and clinical science programs that result in the development of sight-saving treatments. For more information, visit www.nei.nih.gov.

The National Institutes of Health (NIH)—The Nation's Medical Research Agency—includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical, and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

National Eye Institute | EurekAlert!
Further information:
http://www.nei.nih.gov

More articles from Life Sciences:

nachricht At last, butterflies get a bigger, better evolutionary tree
16.02.2018 | Florida Museum of Natural History

nachricht New treatment strategies for chronic kidney disease from the animal kingdom
16.02.2018 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

Im Focus: Autonomous 3D scanner supports individual manufacturing processes

Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).

Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Fingerprints of quantum entanglement

16.02.2018 | Information Technology

'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers

16.02.2018 | Health and Medicine

Hubble sees Neptune's mysterious shrinking storm

16.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>