Gene therapy produces dramatic improvement in vision of children with genetic damage to retinas
Clinical trial researchers at The Children's Hospital of Philadelphia repaired a defective gene that causes progressive blindness and then used a genetically engineered adeno-associated virus vector to inject the gene back into the retinas of five children and seven adults with Leber's congenital amaurosis (LCA). Only one eye in each patient was treated.
Senior author Dr. Jean Bennett, professor of Ophthalmology at the University of Pennsylvania School of Medicine, reported that improvement was "spectacular" in the youngest members of the study group who went from learning Braille to "read[ing] books...and see[ing] what a teacher is writing on a blackboard and...riding their bikes around the neighborhood by themselves."
"This study reports dramatic results in restoring vision to patients who previously had no options for treatment," said Dr. Katherine A. High, co-first author of the study. "These findings may expedite development of gene therapy for more common retinal diseases, such as age-related macular degeneration." While LCA is a rare disease, age-related macular degeneration, which is the result of damage to the retina, is not. Worldwide, 14 million adults each year are afflicted by this disease, representing a huge market for genotoxicity testing.
Best-in-Class Genotoxicity Testing Providers:
- Employ the same route of exposure like inhalation, oral or dermal as the way the toxin infects humans
- Use both male and female animals since some toxic substances have hormonal properties
- Select test animals whose ages match the segment of the human population affected
Top Considerations Before Selecting Genotoxicity Testing Providers:
No single animal species can be used for all genotoxicity tests; selection is a function of the type of genotoxin being studied. In addition, several different species may need to be tested to capture the range of genotoxic effects. Monkeys, our closest genetic cousins, and dogs can only be used in special cases.
Key Producers:
1. Rules-Based Medicine’s (RBM) CustomMAP service comprises Siemens Immulite® 1000 sample testing, Roche Elecsys® sample testing, single assay ELISAs validation and sample testing, assay development and data mining. RBM’s Rat & Human KidneyMAP panels provide sensitive detection and quantitation of kidney damage caused by drug-induced renal toxicity, which is a leading cause of failure in drug development programs. These panels have the degree of sensitivity required to identify kidney damage before it becomes permanent. Corporate headquarters and CLIA-certified biomarker testing laboratory are in Austin, TX; multiplex assay development and manufacturing is in Lake Placid, NY and a subsidiary unit is located in Germany.
2. The Jackson Laboratory’s focus has been on genetics since its inception in 1929 as one of the first centers for cancer genetics research. It offers state-of-the-art facilities, research support and a wide range of technologies, as well as mice colonies, to organizations around the world engaged in geotoxicity testing. The Jackson Laboratory is currently engaged in research into a wide range of genetic diseases in addition to cancer. This independent, non-profit laboratory has two facilities in Maine and California and plans for a third in Florida, which will be funded by the state. The Jackson Laboratory also advances science by offering academic programs for teachers and students as well as for corporate researchers.
3. LAB Research is a preclinical service company offering a wide range of drug development services around the world including: General Toxicology, Safety Pharmacology, Juvenile Toxicology, Immuno Toxicology, Ecotoxicology, Bio/Analytical Chemistry, Infusion Toxicology and Inhalation Toxicology. LAB Research began in Canada in 1998 as LAB Pre-Clinical Research International Inc. The acquisition in 2003 of LAB Research Hungary added genotoxicity, ecotoxicology, reprotoxicology, inhalation and general toxicology to its services. LAB Research Denmark, which specializes in minipig toxicology in addition to providing dermal studies, genotoxicity, reproductive and general toxicology, was purchased in 2005.
4. Pathology Experts LLC offers preclinical research expertise, based on toxicologic pathology, regulatory and genetic toxicology to pharmaceutical and biotechnology sponsors in the form of either a single scientist or a team of experts. This company can act as a “Virtual Toxicologic Pathology Department.” PELLC reports that "We also have a great resource in our Board of Scientific Advisors. In select situations we offer teams of scientists whose specific expertise matches the needs of a sponsor." This private company has offices in Rye, New York and Basel, Switzerland.
Genotoxicity Testing
Definition: Genotoxicity testing determines if a chemical or substance causes damage to a DNA molecule often resulting in mutations or cancer.
