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 Staying in Shape
16.08.2018 | Max-Planck-Institut für molekulare Zellbiologie und Genetik

nachricht Chips, light and coding moves the front line in beating bacteria
16.08.2018 | Okinawa Institute of Science and Technology (OIST) Graduate University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Staying in Shape

16.08.2018 | Life Sciences

Diving robots find Antarctic seas exhale surprising amounts of carbon dioxide in winter

16.08.2018 | Earth Sciences

Protein droplets keep neurons at the ready and immune system in balance

16.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>