Dec 30, 2014
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Recent technical advances have led to the demonstration of the molecular basis of various ocular diseases. Gene transfer into ocular tissues has been demonstrated with growing functional success and may develop into a new therapeutic tool for clinical ophthalmology. There are prospects for commercially available gene therapies for retinal disease in the near future and one thing is for certain that the future is brighter for thousands of patients with inherited retinal degenerations potentially amenable to treatment with this technology.
Gene therapy is the addition of new genes to a patient’s cells to replace missing or defective copies, to restore or impart a new function to overcome a disease usually of genetic origin. Over the past several years, the unlocking of the human genome and the discovery that certain genes, or lack thereof or genetic defects therein, can be the cause of certain diseases has led to the ability to identify genes associated with retinal and other ocular diseases. According to the eyeGene National Ophthalmic Disease Genotyping Network, more than 100 ocular gene types have been identified, and the number increases yearly. To date, the genes for some 35 ocular disorders have been identified. Ophthalmologic disorders are responsible for 48% of the population becoming totally blind. In addition, more than 60 million people suffer from glaucoma and an increasing aging population is also resulting in more people suffering from refractive errors. It is estimated that in the U.S. and Europe, refractive errors affect more than 30% of the population aged 40 or older. Ocular gene therapy research has made rapid progress in the past few years. Although laboratory and animal experiments started were successful many years ago, the application in human beings took very long due to several biological and regulatory hurdles. However, the recent successful gene therapy clinical trials are promising and encouraging.
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The eye is an attractive target for gene therapy because of its accessibility and its immune privilege. Significant advancements have been made in understanding the genetic pathogenesis of ocular diseases, and gene replacement and gene silencing have been implicated as potentially efficacious therapies. Recent improvements have been made in the safety and specificity of vector-based ocular gene transfer methods. Proof-of-concept for vector-based gene therapies has also been established in several experimental models of human ocular diseases. Novel methods are being developed to enhance the performance and regulation of recombinant adeno-associated virus and lentivirus-mediated ocular gene transfer. Gene therapy prospects have advanced for a variety of retinal disorders, including retinitis pigmentosa, retinoschisis, Stargardt disease and age-related macular degeneration. Advances have also been made using experimental models for non-retinal diseases, such as uveitis and glaucoma.
Current and possible candidates for gene therapy in the field of Ophthalmological disorders include Leber’s Hereditary Optic Neuropathy (LHON) (Leber optic atrophy), Juvenile Macular Degeneration (Stargardt Disease) and Ocular Pain etc. The three main types of gene therapies used in the field of ophthalmological disorders are gene replacement for loss-of-function mutations, gene knockdown for gain-of-function mutations, and gene enhancement/knockdown for non-monogenic diseases. However, all of these approaches have historically been subject to the same limitations: 1) how to deliver the vector into the affected cells 2) how to achieve broad distribution throughout the tissue of interest 3) how to maintain persistent transgene expression and functional rescue and 4) how to avoid both local and systemic toxic responses. Inspite of this gene therapy holds the promise of curing ocular diseases, and improving the quality of life for millions who suffer from visual impairments.
Many companies are investing in and researching on this field using gene therapy due to its promising effects. Large Pharmaceutical and Biotech giants, such as Applied Genetic Technologies Corporation (AGTC), Oxford Biomedica, and Pfizer etc., are operating in the field of ophthalmologic disorders in the gene therapy domain. A growing number of partnership between companies in drug development for example between Sanofi and Oxford Biomedica etc., are driving the new gene therapy research. The industry’s collective pipeline is brimming with 300+ therapies for various therapeutic areas. The recent success of gene replacement therapy for ophthalmological disorders is a big step forward in the field of genomic medicine. These results have enthused the medical community and basic scientists equally and have unveiled the potentials that is in store for the future of medicine. Once these experiments are refined and tailored to the needs of these patients with unambiguous success, nearly 500 eye genetic diseases and 1500 genetic diseases in other parts of the body could be potentially cured.
DelveInsight’s Gene Therapy Reports cover the entire gene therapy market insights for ophthalmologic disorders including technology assessments, licensing opportunities, collaborations, market trends, pipeline coverage and competitive landscape. The report essentially provides DelveInsight’s proprietary market and pipeline analytics which identifies the front runners in this therapeutic area. It also identifies the potential market movers and future regulatory landscape.
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