Science Current Events | Science News | Brightsurf.com
 
Email a Friend Send to a friend
Printer Friendly Print 1 shot of gene therapy and children with congenital blindness can now see

1 shot of gene therapy and children with congenital blindness can now see

October 26, 2009

Born with a retinal disease that made him legally blind, and would eventually leave him totally sightless, the nine-year-old boy used to sit in the back of the classroom, relying on the large print on an electronic screen and assisted by teacher aides. Now, after a single injection of genes that produce light-sensitive pigments in the back of his eye, he sits in front with classmates and participates in class without extra help. In the playground, he joins his classmates in playing his first game of softball.

His treatment represents the next step toward medical science's goal of using gene therapy to cure disease. Extending a preliminary study published last year on three young adults, the full study reports successful, sustained results that showed notable improvement in children with congenital blindness.




The study, conducted by researchers from the University of Pennsylvania School of Medicine and the Center for Cellular and Molecular Therapeutics at The Children's Hospital of Philadelphia, used gene therapy to safely improve vision in five children and seven adults with Leber's congenital amaurosis (LCA). The greatest improvements occurred in the children, all of whom are now able to navigate a low-light obstacle course-one result that the researchers call "spectacular."

"This result is an exciting one for the entire field of gene therapy," said Katherine A. High, M.D., co-first author of the study and the director of the Center for Cellular and Molecular Therapeutics, the facility that sponsored the clinical trial at The Children's Hospital of Philadelphia. High, an investigator of the Howard Hughes Medical Institute and a past president of the American Society of Gene Therapy, has been a pioneer in translational and clinical studies of gene therapy for genetic disease. "This study reports dramatic results in restoring vision to patients who previously had no options for treatment," said High. "These findings may expedite development of gene therapy for more common retinal diseases, such as age-related macular degeneration."

Although the patients did not attain normal eyesight, half of them (six of 12) improved enough that they may no longer be classified as legally blind. "The clinical benefits have persisted for nearly two years since the first subjects were treated with injections of therapeutic genes into their retinas," said senior author Jean Bennett, M.D., Ph.D., F.M. Kirby professor of Ophthalmology at the University of Pennsylvania School of Medicine. For Bennett, the results build on nearly 20 years of gene studies on hereditary blindness, starting with pioneering work in mice and dogs. "These remarkable results," she added, "have laid a foundation for applying gene therapy not only to other forms of childhood-onset retinal disease, but also to more common retinal degenerations."

The study team reported their findings today in an online article in The Lancet.

"Children who were treated with gene therapy are now able to walk and play just like any normally sighted child," said co-first author Albert M. Maguire, M.D., an associate professor of Ophthalmology at Penn and a physician at Children's Hospital. "They can also carry out classroom activities without visual aids."

Maguire and Bennett have been researching inherited retinal degenerations for nearly 20 years. Leber's congenital amaurosis, the target of this current study, is a group of inherited blinding diseases that damages light receptors in the retina. It usually begins stealing sight in early childhood and causes total blindness during a patient's twenties or thirties. Currently, there is no treatment for LCA.

Walking along a dimly lit, simulated street route, the children were able to negotiate barriers they bumped into before the surgery. Another child, who since birth, could only see light and shadows, stared into his father's face and said he could see the color of his eyes. Later they played soccer together.

For children and adults in the study, functional improvements in vision followed single injections of genes that produced proteins to make light receptors work in their retinas.

The 12 subjects ranged in age from 8 to 44 years old at the time of treatment. Four of the children, aged 8 to 11, are the world's youngest individuals to receive gene therapy for a non-lethal disease (A fifth subject was 17 years old). On the other end of the age scale, the 35-year-old man and 44-year-old woman are the oldest patients to ever receive gene therapy for retinal degeneration.

For the current human trial, the research team used a vector, a genetically engineered adeno-associated virus, to carry a normal version of the gene, called RPE65, that is mutated in one form of LCA, called LCA2, that accounts for 8 to 16 percent of all LCA cases. Jeannette Bennicelli, Ph.D., in Bennett's laboratory, cloned the gene. The clinical vector production facility at Children's Hospital's Center for Cellular and Molecular Therapeutics (CCMT), directed by Fraser Wright, Ph.D., manufactured the vector.

The clinical trial brought together subjects and scientists from two continents. Five patients enrolled in the study were identified at the Department of Ophthalmology at the Second University of Naples, an institution with a long-standing program in researching inherited retinal diseases, under the supervision of Francesca Simonelli, M.D. Two children from Belgium were recruited through Ghent University Hospital, under the supervision of Bart Leroy, M.D., Ph.D. Jennifer Wellman, of the CCMT, directed all local and federal regulatory interactions for the study.

Another co-author, Edwin Stone, M.D., Ph.D., Howard Hughes Medical Institute Investigator and director of the Carver Center, a genetic testing laboratory at the University of Iowa, identified and verified several of the disease-causing mutations in the study subjects.

In April 2008, the current study team published encouraging preliminary results in the New England Journal of Medicine regarding three young adults, the first to receive gene therapy in this current clinical trial. Those subjects showed improvements in their visual function in both objective vision tests and subjective reports by the patients themselves. Patients who could only detect hand movements gained the ability to read lines on an eye chart.

After the first group of three young adults was treated safely, the study team extended gene therapy to five children from the United States, Italy and Belgium, in addition to four other adults. Because animal studies conducted by Bennett and colleagues had shown that visual improvement was age-dependent, the researchers tested the hypothesis that younger human subjects would receive greater benefits from the treatment. "LCA is a progressive disease, so if a treatment was possible, it was plausible to intervene before damage to the retina was severe," said Bennett.

In all, 12 patients received the gene therapy via a surgical procedure performed by Maguire starting in October 2007 at The Children's Hospital of Philadelphia. For each subject, Maguire injected the therapeutic genes into the eye with poorer function. There were three patient cohorts, receiving low, middle and high doses. No serious adverse events occurred in any of the test subjects.

Starting two weeks after the injections, all 12 subjects reported improved vision in dimly lit environments in the injected eye. An objective measurement, which measures how the eye's pupil constricts, showed that all the subjects were able to detect significantly more light after treatment and also showed greater light sensitivity in each patient's treated eye compared to the untreated eye. In addition, before treatment, nine patients had nystagmus, an involuntary movement of the eyes that is common in LCA. After treatment, seven of them had significant improvements in nystagmus.

Some of the most dramatic results, captured on video by the researchers, are apparent as subjects traverse a standardized obstacle course. Before the treatment, the patients had great difficulty avoiding barriers, especially in dim light. After treatment, the children navigated the course more quickly, with fewer errors than before, even at the lowest light levels. Not all the adults performed better on the mobility course, and for those who did, the improvements were more modest compared to the children's.

"In follow-up studies, we will continue to monitor these patients to determine whether this treatment stops the progression of this retinal degeneration," said Maguire. "In the future, we hope to investigate whether other retinal disease will be amenable to this gene therapy approach."

University of Pennsylvania School of Medicine



Related Gene Therapy Current Events and Gene Therapy News Articles Gene Therapy Current Events and Gene Therapy News RSS Gene Therapy Current Events and Gene Therapy News RSS
Research reveals lipids' unexpected role in triggering death of brain cells
The lipid that accumulates in brain cells of individuals with an inherited enzyme disorder also drives the cell death that is a hallmark of the disease, according to new research led by St. Jude Children's Research Hospital investigators.

No-entry zones for AIDS virus
The AIDS virus inserts its genetic material into the genome of the infected cell. Scientists of the German Cancer Research Center have now shown for the first time that the virus almost entirely spares particular sites in the human genetic material in this process. This finding may be useful for developing new, specific AIDS drugs.

Cornell researchers identify a weak link in cancer cell armor
The seeming invincibility of cancerous tumors may be crumbling, thanks to a promising new gene therapy that eliminates the ability of certain cells to repair themselves.

Treatment to improve degenerating muscle gains strength
A study appearing in Science Translational Medicine puts scientists one step closer to clinical trials to test a gene delivery strategy to improve muscle mass and function in patients with certain degenerative muscle disorders.

Iowa State University researcher discovers key to vital DNA, protein interaction
A researcher at Iowa State University has discovered how a group of proteins from plant pathogenic bacteria interact with DNA in the plant cell, opening up the possibility for what the scientist calls a "cascade of advances."

Scientists successfully reprogram blood cells
Researchers have transplanted genetically modified hematopoietic stem cells into mice so that their developing red blood cells produce a critical lysosomal enzyme -preventing or reducing organ and central nervous system damage from the often-fatal genetic disorder Hurler's syndrome.

Immune therapy can protect against or treat later lymphoma
Specially developed immune system cells that target the common Epstein-Barr virus can protect immune-suppressed bone marrow transplant recipients against lymph system disease and cancers that arise from the viral infection.

Caltech researchers show efficacy of gene therapy in mouse models of Huntington's disease
Researchers at the California Institute of Technology (Caltech) have shown that a highly specific intrabody (an antibody fragment that works against a target inside a cell) is capable of stalling the development of Huntington's disease in a variety of mouse models.

Immunotherapy demonstrates long-term success in treating lymphoma
Targeted immunotherapy has been an attractive new therapeutic area for a number of cancers because it has the potential to destroy tumor cells without damaging surrounding normal tissue. New study results demonstrate high success rates using specialized white blood cells to prevent or treat lymphoma associated with the Epstein-Barr virus (EBV-lymphoma) in patients who have received a hematopoietic stem cell transplant (HSCT).

Toward bold new anti-cancer medicines
Bold new strategies in the battle against cancer may turn forms of the disease that presently are incurable into manageable conditions that can be controlled for long periods of time.
More Gene Therapy Current Events and Gene Therapy News Articles
Gene Therapy: Treating Disease by Repairing Genes (New Biology)

Gene Therapy: Treating Disease by Repairing Genes (New Biology)
by Joseph, Ph.D. Panno (Author)

Many diseases are caused by a simple point mutation - they are the result of a single defective gene. Gene therapy is the attempt to replace a defective gene with a good copy or to add a good gene to compensate for the bad. Although this procedure has proven to be extremely hazardous, of all the technologies provided by the new biology, gene therapy holds much potential for curing disease. Dealing with one of the most controversial aspects of the new biology, Gene Therapy explores the development and future of this area of research and explains why it is considered such a promising branch of science. This encyclopedia presents an overview of genetic defects, viruses, and gene therapy in a way that students and general readers will find easy to understand. Comprehensive in scope, this book...

Gene and Cell Therapy: Therapeutic Mechanisms and Strategies, Third Edition

Gene and Cell Therapy: Therapeutic Mechanisms and Strategies, Third Edition
by Nancy Smyth Templeton (Editor)

Since the publication of the second edition of this book in 2004, gene therapy and cell therapy clinical trials have yielded some remarkable successes and some disappointing failures. Now in its third edition, Gene and Cell Therapy: Therapeutic Mechanisms and Strategies assembles many of the new technical advances in gene delivery, clinical applications, and new approaches to the regulation and modification of gene expression.

New Topics Covered in this Edition: Gene and Cell Therapies for Diabetes and Cardiovascular Diseases Clinical Trials Human Embryonic Stem Cells Tissue Engineering Combined with Cell Therapies Novel Polymers Relevant Nanotechnologies SiRNA Therapeutic Strategies Dendrimer Technologies

Comprised of...

Gene Therapy

Gene Therapy
by Mary Colavito (Author), Michael A. Palladino (Author)

KEY MESSSAGE: Will gene therapy one day become the ultimate application of genetic technology?  Gene Therapy, the newest booklet in the Special Topics in Biology Series, addresses this question by exploring gene therapy as a complex technology for delivering therapeutic genes as a way to treat and cure human genetic diseases. Author Mary Colavito provides an overview of the basic science involved in gene therapy methods and chronicles the history of gene therapy by discussing successful and ongoing gene therapy treatments as well as adverse outcomes in some cases of gene therapy. Also discussed are challenges that must be overcome for gene therapy to become a more reliable and readily accessible approach for treating a multitude of genetic diseases that affect...

Gene Therapy and Gene Delivery Systems (Advances in Biochemical Engineering / Biotechnology)

Gene Therapy and Gene Delivery Systems (Advances in Biochemical Engineering / Biotechnology)
by David V. Schaffer (Editor), Weichang Zhou (Editor)

1 D.V. Schaffer, W. Zhou: Gene Therapy as Future Human Therapeutics.- 2 J. Heidel, S. Mishra, M.E. Davis: Molecular Conjugates.- 3 M. Manthorpe, P. Hobart, G. Hermanson, M. Ferrari, A. Geall, B. Goff, A. Rolland: Plasmid Vaccines and Therapeutics: From Design to Applications.- 4 S.R. Little, R. Langer: Non-Viral Delivery of Cancer Genetic Vaccines.- 5 J.C. Grieger, R.J. Samulski: Adeno-Associated Virus as a Gene Therapy Vector: Vector Development, Production and Clinical Applications.- 6 J.H. Yu, D.V. Schaffer: Advanced Targeting Strategies for Murine Retroviral and Adeno-Associated Viral Vectors.- 7 N. Loewen, E.M. Poeschla: Lentiviral Vectors.- 8 N.E. Altaras, J.G. Aunins, R.K. Evans, A. Kamen, J.O. Konz, J.J. Wolf: Production and Formulation of Adenovirus Vectors.-

  Gene Therapy & Molecular Biology
by Intl Soc Gene Therapy Mole Bio



Immunology of Gene Therapy

Immunology of Gene Therapy
by Roland W. Herzog (Author)

Summarises and reviews the important field of genetic therapy with respect to the latest immunological advances in the lab and clinic Unique treatment of immunology and immunotherapy in gene - approached from a vector and target organ point of view rather than from the perspective a specific diseases Broad appeal - applicable for  immunology and genetics / gene therapy, recombinant DNA studies, transplantation, virology, cancer research and tumor research

Jazz Therapy, Vol. 1: Smile

Jazz Therapy, Vol. 1: Smile
by Gene Bertoncini & Roni Ben-Hur

The first in a new series of fundraising CDs produced in association with the Jazz Foundation of America, and the first time these two popular guitarists have recorded together. Liner notes by Ira Gitler. Entire CD was played, recorded, packaged, and is being promoted on a pro-bono basis, raising funds for the Englewood Hospital and Medical Center's Dizzy Gillespie Fund.

Sexual Therapy (Watch ya Step Mix)

Sexual Therapy (Watch ya Step Mix)
Gene Farris (Primary Contributor)



Gene Therapy: Dawn of a New Age in Medicine (NCME Video 653)

Gene Therapy: Dawn of a New Age in Medicine (NCME Video 653)
Also With: Kenneth W. Culver (Primary Contributor), Network For Continuing Medical Education (Primary Contributor)



Chromosome 11 Gene Therapy Sickle Cell Anemia Photographic Poster Print, 24x32

Chromosome 11 Gene Therapy Sickle Cell Anemia Photographic Poster Print, 24x32
by Art.com

Art.com is the world's largest retailer of art prints, posters, photographs, and framed artwork. With our huge selection of over 400,000 prints, you'll easily find the perfect piece for your home, office, or classroom. Our art is printed on quality paper. When you order framed artwork, the piece is built by our team of in-house professionals. Visit our Amazon store today at www.amazon.com/artdotcom to find Special Offers and search for products based on 'Artist Name' and 'Subject Categories' such as Movie, Music, Vintage, TV, Children, Travel, Kitchen, Museum Art, Animals, Floral, Motivational, and Sports. Art.com is dedicated to providing you with high quality products and service by offering you 100% satisfaction guaranteed. We ship internationally to over 80 countries. Decorate your...

© 2009 BrightSurf.com