On September 16, 2024, AAVantgarde announced that the first participant received a dose in the Phase 1/2 LUCE-1 clinical trial for vision loss caused by Usher syndrome type 1B.
Inherited retinal diseases are degenerative eye diseases that cause progressive vision loss. They can potentially lead to complete blindness and severely impact a patient’s quality of life.
Therapeutic research begins with testing new therapies in laboratory models of the disease before moving to human trials. However, translating success from models (cells or animals) to humans is challenging because they develop function and symptoms at different rates.
A group of researchers from Harvard Medical School and the University of Basel tested a gene therapy on mice with mutations in the PCDH15 gene, which causes USH1F.
In research supported by the Usher 1F Collaborative, Genetic Cures Australia, and NIDCD/NIH, a group of researchers studied how to deliver a gene therapy to mice with mutations in the PCDH15 gene, which causes USH1F.
Usher syndrome (USH) is classified into three major clinical subtypes (types 1–3), with type 1 being the most severe.
CRISPR/Cas9 cuts both strands of the DNA, while prime editing cuts only one strand, to repair genetic mutations.
Around 40,000 patients in the world have Usher syndrome type 2C, which typically presents with congenital hearing loss and retinitis pigmentosa (RP) due to mutations on the ADGRV1 gene.
Dr. Corey's goal is to rescue vision, but he is testing first on hearing because it’s easier to measure in a mouse model. Because babies with Usher 1 are born profoundly deaf but sighted, researchers believe that the hearing is more sensitive to the absence of the protein than vision. Therefore, if a gene therapy rescues hearing, theoretically, it should also rescue vision.
MYO7A is a large gene that encodes myosin VIIA, a protein that helps maintain stereocilia in the inner ear and the retinal pigment epithelium in the retina.
Researchers used CRISPR/Cas9 technology to disrupt the MYO7A gene in monkeys to create a nonhuman primate model for Usher syndrome type 1B (USH1B).
In retinal degenerative diseases, once light and color-sensing photoreceptor cells degrade and die, they cannot self-regenerate in mammals.
Glycolysis is the process by which our bodies generate energy by converting glucose into pyruvate.
In a guest column at clinicalleader.com, the authors discuss the past and exciting future prospects of optogenetic therapies.
The FDA and National Institutes of Health (NIH) are partnering with 15 private organizations to increase the number of gene therapies for rare diseases.
The biopharmaceutical company, Ocugen Inc., has announced that the FDA has accepted their Investigational New Drug (IND) application to start a human clinical trial with OCU400.
The National Institutes of Health (NIH), the U.S. Food and Drug Administration (FDA), 10 pharmaceutical companies, and five non-profits have partnered as the Bespoke Gene Therapy Consortium (BGTC) to help speed up the development of gene therapies for rare diseases.
GenSight Biologics is a biopharmaceutical company that focuses on creating gene therapies for retinal neurodegenerative and central nervous system disorders. They have announced that the FDA has awarded Fast Track Designation of GS030, which uses AAV2 gene therapy combined with optogenetics to treat retinitis pigmentosa.
Nanoscope Therapeutics Inc., a clinical-stage biotechnology company, has recently announced that one of its drugs is approved for Phase 2b clinical trial.
Nanoscope Therapeutics Inc. announced that in their Phase 1/2a clinical study, a year following a single injection of Multi-Characteristic Opsin (MCO) into the eye, there was vision improvement in all patients with retinitis pigmentosa (RP). The MCO gene used in the study is delivered into the retina using AAV2 vectors. 3 patients received low dosage injections and 8 received high dosage. All patients in this study had objective and subjective improvements in functional vision. There was also improvement seen in mobility tests. Most opsins have a limited scope of clinical benefit because they have a narrow band of activation. MCO is sensitive to broadband light and can react to ambient lighting so there is no need for an external light device.
What this means for Usher syndrome: This new therapy seems to be able to restore some vision in patients with RP regardless of the type of mutation that causes it. Because vision loss in Usher syndrome is a type of RP, this new therapy could be beneficial to Usher syndrome patients.
Usher syndrome (USH) is the most common form of genetic deaf-blindness. Thus far there are no treatments for vision loss. Researchers were able to create a pig model for USH1C by introducing a human mutation into the USH1C gene in pigs. This successfully created an animal model with the hearing defect, vestibular dysfunction, and visual impairment found in USH. The primary cell isolated from these pig models and USH1C patients show elongated primary cilia compared to primary cells with no USH mutations. This finding confirms USH as a genetic disorder that affects cilia. The research also proves that there can be therapeutic benefits in gene supplementation and gene repair therapies.
What this means for Usher syndrome: Researchers have now confirmed that USH is a genetic disorder affecting cilia. Knowing this enables possible therapies like gene supplementation and gene repair.
Retinitis pigmentosa (RP) is a rare genetic disease that causes loss of photoreceptors, which are the light sensitive cells in the retina. This disease can lead to blindness and affects more than 2 million people worldwide. In a groundbreaking clinical trial led by Paris-based GenSight Biologics, a man who was blind for 40 years successfully regained some visual function with a technique called optogenetics. Optogenetics uses light to control neuron activity. In this study, a light-sensing protein called ChrimsonR was injected into the eye and delivered to the patient’s retinal cells. After a four-month period to allow his body to make ChrimsonR protein, the patient was fitted with special goggles that detect and shift incoming light into a specific color range. The patient was able to see high-contrast images and objects, and his brain activity was the same as someone with normal sight.
What this means for Usher syndrome:
More patients will need to be enrolled and evaluated, but if this study proves to be successful, RP patients who are blind may be able to regain some sight, increasing their quality of life. Because vision loss in Usher syndrome is a type of RP, this therapy may also be beneficial for Usher syndrome patients.
The company, Vedere Bio II, is working on optogenetic gene therapies based largely on the work of University of California, Berkeley, neuroscientists Ehud Isacoff and John G. Flannery to restore vision.
A team of researchers at Tel Aviv University are studying a virus-based gene therapy approach to treat deafness by replacing the non-functioning gene with a functional copy.
Researchers have found that using liposomes triggered by light to deliver CRISPR gene therapy, rather than viruses, is a safer and more targeted method.
Vedere Bio, Inc., a company focused on photoreceptor-protein-based optogenetic therapies (use of light to modulate neurons that have been genetically modified) to restore vision has been acquired by Novartis.
The National Eye Institute, part of the National Institutes of Health, had provided a research grant to Nanoscope, LLC for their development of MCO1.
In a proof-of-concept study, researchers found evidence of the potential of base editors to correct mutations that cause inherited retinal diseases (IRD).
Two scientists, Emmanuelle Charpentier and Jennifer Doudna, have been awarded the 2020 Nobel Prize in Chemistry for developing the tools to edit DNA. They are the first two women to share the prize, which honors their work on the technology of genome editing. During Professor Charpentier’s studies of bacterium Streptococcus pyogenes, she discovered a previously unknown molecule called tracrRNA, which is part of the organism’s immune system. This system, now known as CRISPR/Cas9, disrupts viruses by cleaving (or cutting) their DNA – like genetic scissors. Drs. Charpentier and Doudna together recreated this system in a test tube and showed it can be reprogrammed to cut any DNA molecule at a predetermined site. Since this discovery, the CRISPR/Cas9 gene editing system has already contributed to many important discoveries in basic research; and is currently being investigated for its potential to treat sickle cell anaemia, a blood disorder that affects millions of people worldwide. In medicine, clinical trials of new cancer therapies are underway, and this technology may also have the potential to treat or even cure inherited diseases.
What this means for Usher syndrome: Researchers have already started to evaluate the use of CRISPR/Cas9 gene editing to target specific mutations in patients with USH2A. Successful in-vitro (outside the body) mutation repair was demonstrated with proven effectiveness and specificity. This indicates the CRISPR/Cas9 gene editing system shows promise and should be further explored as a potential treatment for Usher syndrome.
Delivery of therapeutic genes into retina is proving to reverse degeneration and restore vision, however, viral vector-based gene delivery is prone to immunorejection, inflammatory/immune-response and nontargeted. Here, we report nonviral gene delivery and expression of opsin encoding genes in mouse retina in-vitro and in-vivo by use of pulsed femtosecond laser microbeam. In-vitro patch-clamp recording of the opsin-sensitized retinal cells and visually evoked in-vivo electrical recording from laser-transfected eye of mouse with degenerated retina showed functional response. The ultrafast laser-based naked gene delivery showed minimal damage and reliable expression of therapeutic opsin in cell membrane of the selected cells and in targeted retinal region. Laser-based "naked DNA gene therapy" in a spatially targeted manner will pave the way for treatment of inherited retinal diseases.
What this means for Usher syndrome: Based on this study, laser-based delivery of gene therapy appears to be a viable alternative to viral-vector based gene delivery with less adverse effects. In the future, this may translate into more, and safer, treatment options for Usher patients.
Eyevensys, a biotechnology company developing non-viral gene therapies for ophthalmic diseases, today announced the U.S. Food and Drug Administration (FDA) has granted an orphan-drug designation (ODD) for EYS611 for the treatment of retinitis pigmentosa (RP). EYS611 is a DNA plasmid that encodes for the human transferrin protein which helps manage iron levels in the eye. While iron is essential for retinal metabolism and the visual cycle, too much iron is extremely toxic to the retina and has been associated with photoreceptor death in several retinal degenerative diseases. By acting as an iron chelating and neuroprotective agent (an agent that reduces level of toxic metals in the blood and tissues), EYS611 helps slow the progression of diseases like RP regardless of the specific genetic mutation causing the condition. This can potentially benefit patients diagnosed with RP, as well as other degenerative retinal diseases, including late stage, dry age-related macular degeneration and glaucoma. Eyevensys just reported data from preclinical testing in the September 2020 issue of the journal Pharmaceutics. The paper, entitled “Transferrin non-viral gene therapy for treatment of retinal degeneration” (Bigot, et al., Pharmaceutics), shows that EYS611 is safe and effective for preserving photoreceptors and retina functionality in acute toxicity and inherited rat models of retinal degeneration.
What this means for Usher syndrome: The orphan-drug designation by the FDA means that Eyevensys has been granted a seven year window to exclusively develop EYS611. This gene therapy is intended for all RP patients regardless of the underlying mutation, is less invasive than viral-vector gene therapies, and can be used at earlier stages of the disease. Since this is not mutation specific, this non-viral gene therapy will be a viable option for Usher patients.
This year’s Körber Prize for European Science was given to a Hungarian scientist whose revolutionary gene-editing treatment could cure a type of blindness that affects around one in 4,000 children. Cell biologist Botond Roska’s pioneering work on the human retina has placed him among the world leaders in the study of ophthalmology—work that included the presumably painstaking effort of identifying over 100 different retina cell types and their complex interrelations. His work on novel gene therapies has led to discovery of a possible cure for retinitis pigmentosa. Roska’s work which involves the reprogramming of retina cells into photoreceptors, thereby taking over from the damaged ones and restoring light and color in blind retina, is currently going through clinical trials. As a result of this ground-breaking discovery, he was granted the prestigious award of €1 million.
What this means for Usher syndrome: If proven successful, this novel gene therapy may restore partial vision to affected Usher patients by enabling previously blind retinas to detect light and color.
For the first time, scientists have used the gene-editing technique CRISPR to try to edit a gene while the DNA is still inside a person’s body. The procedure involved injecting the microscopic gene-editing tool into the eye of a patient blinded by a rare genetic disorder, in hopes of enable the participant to see. Researchers hope to know within weeks with the approach is working and, if so, to know within two or three months how much vision will be restored.
What this means for Usher syndrome: If successful, this will be a huge step forward towards the development of therapies to restore vision in Usher patients.
Ocugen Inc., a clinical-stage company focused on discovering, developing, and commercializing transformative therapies to treat rare ophthalmic diseases, announced today in the publication in 'Nature Gene Therapy' preclinical data of nuclear hormone receptor gene NR2E3 as a genetic modifier and therapeutic agent to treat multiple retinal degenerative diseases. The publication details efficacy results in five different mouse models of RP that underwent administration of NR2E3-AAV by subretinal injection. The study demonstrates the potency of a novel modifier gene therapy to elicit broad-spectrum therapeutic benefits in early and intermediate stages of RP.
What this means for Usher syndrome: This gene modifier has been successfully tested in five genetic mouse models for RP. Although nothing is known regarding the involvement of this modifier in Usher syndrome, it will be interesting to know whether this modifier can rescue photoreceptor activity in animal models for Usher syndrome. If it does, it will mean it can be used in gene therapy or as a drug target.
Allergan, a global pharmaceutical company, and Editas Medicine, a genome editing company, have announced treatment of the first patient in the BRILLIANCE clinical trial for AGN-151587 (EDIT-101) at Oregon Health & Science University (OHSU) Casey Eye Institute. AGN-151587 is a CRISPR-based experimental medicine under development for the treatment of Leber congenital amaurosis 10 (LCA10), an inherited form of blindness cau sed by mutations in the centrosomal protein 290. This potential treatment targets photoreceptor cells and is delivered via sub-retinal injection. The BRILLIANCE clinical trial is the world’s first human study of an in vivo (inside the body) CRISPR genome editing medicine, and is currently in Phase I/2 to assess the safety, tolerability, and efficacy of AGN-151587 in approximately 18 patients with LCA10.
What this means for Usher syndrome: If the clinical trial is successful, this CRISPR-based treatment which targets photoreceptor cells may be an option for other forms of blindness, including Usher syndrome.
In this study, a nuclear hormone receptor (NHR, a type of protein) gene Nr2e3 was tested as a possible general therapy to reduce the effects of early to intermediate stages of retinal degeneration in five mouse models of retinitis pigmentosa (RP).
Gene-infused nanoparticles used for combating disease work better when they include plant-based relatives of cholesterol because their shape and structure help the genes get where they need to be inside cells. The type of nanoparticle used to deliver genes in this study has already been clinically approved; it's being used in a drug given to patients with a progressive genetic condition called amyloidosis.
What this means for Usher syndrome: This new nanoparticle composition could be a more efficient alternative strategy to deliver the wild type gene into the photoreceptors of Usher patients.
Usher syndrome, a genetic condition that results in hearing and vision loss in childhood, affects about 4 out of every 100,000 Canadians. Fighting Blindness Canada (FCB) has provided new funding that will allow Vincent Tropepe, the professor and departmental chair of cell and systems biology in the Faculty of Arts & Science, to try to identify the causes of retinal degeneration due to Usher. Tropepe’s lab will focus on a particular protein associated with the mutated gene that is also thought to be crucial to the photoreceptors’ larger support system. If researchers can find defects in this protein and the structure it is part of, they may be able to reveal new mechanisms that maintain the stability and functionality of the photoreceptors.
What this means for Usher syndrome: If they can find an association between photoreceptor survival and this protein, this will lead to novel gene therapy strategies and, maybe to the discovery of therapeutic drugs that will help to stabilize the larger photoreceptor structure when that particular protein is dysfunctional.
Mice born blind have shown significant improvement in vision after undergoing new gene therapy developed by a team of Japanese scientists. This new method is an alternative strategy of gene supplementation, which involves supplementing the defective gene, such as the ones that can lead to inherited retinal degeneration with a healthy one. The healthy gene is delivered through an AAV vector, but the virus can only hold a small healthy gene. Therefore, patients with large genes cannot be treated with this method. This new gene therapy combines AAV vector delivery with CRISPR-Cas9 technology, this way researchers can target a specific defective gene, cut it out and glue in a healthy replacement. This approach rescued 10% of the photoreceptors, resulting in a visual improvement very similar to gene supplementation therapy.
What this means for Usher syndrome: This is an alternative strategy that can be developed into new therapies to treat Usher patients, but only those harboring mutations in the small genes (USH1C, USH1G, DFNB31 and USH3A).
A team of researchers from Massachusetts Eye and Ear have identified a cellular entry factor for the adeno-associated virus vector (AAV) types—the most commonly used virus vector for in vivo gene therapy. The researchers identified that GPR108, a G protein-coupled receptor, served as a molecular lock to the cell. GPR108 is required for most AAVs, including those used in approved gene therapies, to gain access to the cell. Since gaining cellular access is a crucial step in delivering gene therapy, this discovery may provide a crucial piece of information that could one day enable scientists to better explain, predict, and direct AAV gene transfers to specific tissues.
What this means for Usher syndrome: This discovery may improve the chances for targeting gene therapy for Usher syndrome.
Neuroscientists at Lund University in Sweden have developed a new technology that engineers the shell of a virus to deliver gene therapy to the precise cell type that needs to be treated. According to neuroscientist Tomas Björklund, “Thanks to this technology, we can study millions of new virus variants in cell culture and animal models simultaneously. From this, we can subsequently create a computer simulation that constructs the most suitable virus shell for the chosen application.” With this new method, researchers have been able to reduce the need for laboratory animals significantly because millions of the variants of the same drug are studied in the same individual. Additionally, they have been able to move important parts of the study from animals to cultured human stem cells.
What this means for Usher syndrome: This study provides potential methods to deliver genes effectively to the appropriate cells required for vision.
The identification of genetic defects that underlie inherited retinal diseases (IRDs) paves the way for the development of therapeutic strategies. Nonsense mutations result in a premature termination codon (PTC) and cause approximately 12% of all IRD cases. An approach that targets nonsense mutations could be a promising pharmacogenetic strategy for the treatment of IRDs. We provide novel data on the read-through efficacy of Ataluren, a translational read-through inducing drug (TRID), on a nonsense mutation in the Usher syndrome gene USH2A that causes deafblindness in humans. We validated Ataluren's efficacy to induce read-through on a nonsense mutation in USH2A-related IRD. Our findings support the use of patient-derived fibroblasts as a platform for the validation of preclinical therapies.
What this means for Usher syndrome:This study tests a potential therapy that could be used to treat Usher syndrome patients who have nonsense mutations.
Wake Forest Institute for Regenerative Medicine (WFIRM) scientists have fine-tuned their delivery system to send a DNA editing tool to alter DNA sequences and modify gene function. With this new method, researchers can package together the Cas9 protein and guide RNA for the CRISPR mediated gene editing. Previously, the two components—Cas9 protein and guide RNA—had to be delivered separately which was not as efficient. The new system offers the delivery efficiency of conventional lentiviral vectors that enable transient Cas9 expression. Transient Cas9 expression means a decrease chance of having unwanted effects when using this therapy.
What this means for Usher syndrome: For Usher patients, improving the efficacy of CRISPR technology means that they will be able to receive a more efficient treatment with very low side-effects.
Case Western Reserve University (CWRU) and Boston-based genetic medicine company Akouos have entered into an exclusive licensing agreement to develop a patented gene therapy that could potentially treat hearing loss associated with a type of Usher syndrome. It may be able to stop the progression of hearing loss and prevent deafness in people with USH3A. The hearing loss is “sensorineural,” meaning it is caused by abnormalities of the inner ear, while the vision is due to the degeneration of the retina at the back of the eye. The technology has allowed researchers to develop a more precise animal model of the hearing loss associated with Usher syndrome type 3A, and the potential for the technology to deliver the preservation of hearing and quality of life for children and adults diagnosed with the genetic disorder.
What this means for Usher syndrome: The development of a more precise animal model for USH3A will exponentially expedite the identification of novel and more efficient therapies to slow or complete stop the progression of this disease.
CRISPR (clustered regularly interspaced palindromic repeats) is a cutting-edge genetic editing technique that enables the targeting and editing of specific sequences in the human DNA. CRISPR is known to result in unwanted gene edits that can occur when working with embryos. However, if the edits are done on adult humans and children, no transference occurs, and any potential damage remains to one individual. Allergan and Editas Medicine EDIT, a pharmaceutical company in Cambridge, Massachusetts, has announced in July they are ready to enroll subjects into its first of its kind CRISPR-based therapy trials, a development that would involve gene editing inside the human body. A propriety EDIT-101 injection is administrated into the eye to deliver “gene-altering machinery” directly to the photoreceptor cells. Once injected, EDIT-101 cuts out the mutated DNA, including CEP290 gene responsible for progressive photoreceptor-cell loss, which leads to an inherited type of blindness, Leber congenital amaurosis 10. The goal is for this cut to be repair by the DNA-repairing process that will lead to the expression of the normal protein.
What this means for Usher syndrome: potential treatments for vision loss are being discovered every day. In this case, the use of CRISPR technology will help to replace and repair mutations present in the Usher proteins and thus, help to restore vision as well as hearing.
The identification of the causes and understandings of the functions of many inherited retinal diseases (IRDs) has led to the development of exciting new gene/disease specific treatment opportunities. There are numerous treatments available that are aimed at a level of not just targeting specific genes but also certain mutations. Therefore, gene/disease specific treatments rely on persistent target cells and sufficient visual function to work effectively. However, many patients are outside of this window of opportunity and must rely on other approaches.
What this means for Usher syndrome: there are many different treatment and therapy options that are in development for retinitis pigmentosa.
Usher syndrome (USH) is the most common cause of inherited deaf-blindness. Currently there is no therapy for vision loss caused by USH. Rodents have been used as animal models for USH but even with defects in their USH genes, they do not often exhibit the vision loss humans experience. The lack of animal models that share human characteristics of USH makes it difficult to study the protein and any possible therapeutic interventions. In this study, researchers were able to modify the USH1C gene in pigs. They did this by copying the human USH1C gene with the mutation using bacterial recombineering into the pig genome. Through this, researchers were able to create USH1C piglets that are born deaf and have vestibular dysfunctions. Behavioral tests also showed a reduction in vision. This is the first time researchers have created a large animal model for USH1.
What this means for Usher syndrome: Researchers now have a functioning animal model of USH1C that they can use to study the USH1C gene and possible therapies. This allows further research to be conducted for cures for USH.
Researchers developed a mouse model with genetically defective rods that mimics developmental blindness disorders in humans. A team examined the structure of the defective retina, as well as its response to light with or without gene therapy. The rods that received gene therapy not only regained normal light response, but also recovered normal connections to other retinal neurons.
What this means for Usher syndrome: If future treatments for Usher syndrome can save photoreceptors from dying, the saved cells may be able to reconnect and become functional.
OliX Pharmaceuticals Inc. in South Korea, a leading developer of RNAi therapeutics, is expanding its research in ocular diseases.
GenSight Biologics, a biopharma company focused on discovering and developing gene therapies for retinal neurodegenerative diseases and central nervous system disorders, announced that the independent Data Safety Monitoring Board (DSMB) has completed its first safety review of the ongoing PIONEER Phase I/II clinical trial of GS030 combining gene therapy and optogenetics for the treatment of Retinitis Pigmentosa (RP). No safety issues have been found for the first cohort of subjects who received a single intravitreal injection of 5e10 vg combined with a wearable optronic visual stimulation device. Therefore, the DSMB has recommended moving forward with the plan without any modification to the protocol and recruiting the second cohort of subjects to receive an escalated dose of 1.5e11 vg.
What this means for Usher syndrome: This clinical trial could lead to a treatment for RP and may be applicable to Usher syndrome.
Karen Andersen, Samira Kiani and their colleagues at Arizona State University described a method of rendering the CRISPR-Case9 gene-editing tool “immunosilent,” potentially allowing the editing and repair of genes to be accomplished reliably and without activating an immune response. Their study is the first to predict accurately the dominant binding sites or epitopes responsible for immune recognition of the Cas9 protein and experimentally target them for modification. These findings bring CRISPR a step closer to a safer clinical application.
What this means for Usher syndrome: This discovery could help pave the way toward FDA approval of CRISPR/Cas9 gene editing therapies to treat Usher syndrome.
Ophthotech has licensed exclusive rights to develop novel adeno-associated virus (AAV) gene therapy candidates for Best disease and other bestrophinopathies from University of Pennsylvania (Penn) and the University of Florida Research Foundation (UFRF). The agreement allowed Ophthotech to enter talks with Penn and UFRF to acquire a license for novel AAV serotype 2 based gene therapy product candidates for Best disease, an orphan inherited degenerative retinal disease caused by mutations in the BESTI gene. Additionally, Ophthotech says it expects to initiate a Phase I/II clinical trial for the Best disease candidate in the first half of 2021.
What this means for Usher syndrome: If the first clinical trials for Best disease using this novel AVV gene therapy are successful, this means Ophthotech will probably look for other eye-related diseases like Usher syndrome.
Adeno-associated viruses (AAV) engineered to target specific cells into the retina can be injected directly into the vitreous of the eye to deliver genes more precisely than with wild type AAVs, which must be injected directly under the retina. Researchers at the University of California, Berkeley inserted a gene for a green-light receptor into the eyes of blind mice, and a month later the mice could maneuver obstacles as easily as mice without visual impairments. The mice could use motion, brightness changes over time, and fine detail on an iPad.
What this means for Usher syndrome: Retinal delivery of AAV can always have the adverse effects of tissue inflammation and/or retinal detachment. This new strategy, delivering the modified virus into the vitreous, will prevent those side effects. For Usher patients, this means that, if successful, this therapy will increase the probability of success in restoring vision.
Ganglion cells in the eye generate noise as the light-sensitive photoreceptors die in diseases such as retinitis pigmentosa (RP). Now, neurobiologists have found a drug and gene therapy that can tamp down the noise, improving sight in mice with RP. These therapies could potentially extend the period of useful vision in those with degenerative eye diseases, including, perhaps, age-related macular degeneration.
What this means for Usher syndrome: This type of therapy may also extend the period of useful vision in Usher syndrome.
Scientists at the Francis Crick Institute have discovered a set of simple rules that can determine the precision of CRISPR/Cas9 genome editing in human cells. These rules could help to improve the efficiency and safety of genome editing in both the lab and the clinic. By examining the effect of CRISPR genome editing at 1491 target sites across 450 genes in human cells, the team have discovered that the outcomes can be predicted based on simple rules. In this study, researchers have found that the outcome of a particular gene edit depends on the fourth letter from the end of the RNA guide, synthetic molecules made up of about 20 genetic letters (A, T, C, G). “The team discovered that if this letter is an A or a T, there will be a very precise genetic insertion; a C will lead to a relatively precise deletion and a G will lead to many imprecise deletions. Thus, simply avoiding sites containing a G makes genome editing much more predictable.”
What this means for Usher syndrome: Scientists will theoretically be able to repair the mutation present in an Usher gene by selecting the correct genetic letter from the end of the RNA guide.
The light scalpel has the potential of preventing the “ripple effect” that occurs following a trigger that leads to glaucoma or macular degeneration. By utilizing the femtosecond laser, small holes appear in the cells of the eye’s retina, making it possible to effectively inject drugs or genes in specific areas of the eye. The key feature of this technology is extreme precision because through the usage of gold nanoparticles, the light scalpel makes it possible to precisely locate the family of cells where the doctor will have to intervene.
What this means for Usher syndrome: In CRISPR/Cas9 editing or drug delivery, the utilization of the femtosecond laser will improve the delivery of the specific compound to the affected area with minimum side effects.
A US clinician has received a five-year £6.1 million grant to investigate the potential of advancing a gene therapy currently used in dogs to help retinitis pigmentosa (RP) patients. The treatment restored the night vision and stopped the progression of the daytime vision-loss in dogs with progressive retinal atrophy (PRA). PRA is an inherited condition in dogs and is caused by the same genes that are responsible for RP. This new grant will allow clinicians to build on primary studies in preparation for a possible clinical trial in human patients with RP.
For the last couple years, Ophthalmologist Dr. Kang Zhang and UC San Diego researchers have been working with CRISPR by injecting it into the eyes of mice with Retinitis Pigmentosa. According to Dr. Zhang, they have been able to bring back 30 percent of vision and sometimes 50 percent of vision. Zhang’s lab has recently received the green light to start clinical trials this fall and if the trial goes well then CRISPR can be applied to all human genetic diseases or conditions.
Researchers at Duke University believe they have developed an approach to treat retinal conditions such as Retinitis Pigmentosa, which include misfolded proteins in the cell that the eye cannot process. Scientists have shown by boosting the cells’ ability to process misfolded proteins could keep them from clustering inside the cell. They created and tested the strategy in mice, significantly delaying the onset of blindness. This technique would not be used to prevent cell death retinal diseases but also neurodegenerative diseases such as Huntington’s, Parkinson’s, and Alzheimer’s.
Ekaterina S. Lobanova, Stella Finkelstein, Jing Li, Amanda M. Travis, Ying Hao, Mikael Klingeborn, Nikolai P. Skiba, Raymond J. Deshaies, Vadim Y. Arshavsky
New research outlines a strategy that in mouse models significantly delayed the onset of blindness from inherited retinal degeneration such as retinitis pigmentosa.
Bill Whitaker of CBS’s 60 minutes interviewed Feng Zeng to learn more about Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR). Whitaker’s interview with Zhang provides basic facts that are accessible to anyone on CRISPR and its possibility of not only curing genetic diseases but preventing them altogether.
A retinal implant allowed a 69 year old woman with macular degeneration to see more than double the usual number of letters on the vision chart. Luxturna, the gene therapy was approved by the FDA in 2017, corrects a mutation found in Leber congential amaurosis (LCA).
Odylia Therapeutics aims to advance gene therapies that are getting left behind. Odylia’s focus is gene therapies with scientific promise but limited commercial opportunity that maybe gathering dust on the selves of labs or companies.
GenSight will start a clinical trial in the UK testing a combination of gene therapy and a wearable device to restore sight in patients with retinitis pigmentosa. The Phase I and II trial, PIONEER, will study the safety and tolerability of GenSight’s therapy called GS030, in patients with end-stage retinitis pigmentosa with vision not better than “counting fingers.” The first patient will be tested in the first quarter of 2018 and outcomes will be measured after a year.
What this means for Usher syndrome: If GenSight’s therapy succeeds, it will very likely be tested in other diseases such as Usher syndrome.
GenSight Biologics, a biopharma company focused on discovering and developing innovative gene therapies for retinal neurodegenerative diseases and central nervous system disorders, announced UK Medicines and Healthcare Regulatory Agency (MHRA) acceptance of the Company’s Clinical Trial Application (CTA) to initiate the PIONEER Phase I/II study of GS030 in patients with Retinitis Pigmentosa (RP).
Raghavi Sudharsan, Daniel P. Beiting, Gustavo D. Aguirre, William A. Beltran
In studying the late stages of disease in two different canine models of retinitis pigmentosa, a group of progressive and inherited blinding diseases, researchers found commonalities, specifically involving the innate immune system. The findings point to potential new treatment options for the conditions.
Geng R, Omar A., Gopal SR, Chen DH, Stepanyan R, Basch ML, Dinculescu A, Furness DN, Saperstein D, Hauswirth W, Lustig LR, Alagramam KN
Researchers developed a new USH3 mouse model that displays delayed-onset progressive hearing loss, then tested a viral therapy to preserve hearing in the mouse models. Their results show that gene therapy is a promising approach to preserve hearing in USH3 patients.
Samantha R. De Silva, Alun R. Barnard, Steven Hughes, Shu K. E. Tam, Chris Martin, Mandeep S. Singh, Alona O. Barnea-Cramer, Michelle E. McClements, Matthew J. During, Stuart N. Peirson, Mark W. Hankins and Robert E. MacLaren
Oxford researchers have shown that gene therapy might help reverse blindness caused by retinitis pigmentosa by reprogramming cells at the back of the eye to become light sensitive.
View the journal publication of this study: http://www.pnas.org/content/early/2017/09/26/1701589114
Alice Emptoz, Vincent Michel, Andrea Lelli, Omar Akil, Jacques Boutet de Monvel, Ghizlene Lahlou, Anaïs Meyer, Typhaine Dupont, Sylvie Nouaille, Elody Ey, Filipa Franca de Barros, Mathieu Beraneck, Didier Dulon, Jean-Pierre Hardelin, Lawrence Lustig, Paul Avan, Christine Petit, Saaid Safieddine
Scientists have recently restored hearing and balance in a mouse model of Usher syndrome type 1G characterized by profound congenital deafness and vestibular disorders caused by severe dysmorphogenesis of the mechanoelectrical transduction apparatus of the inner ear's sensory cells. These findings open up new possibilities for the development of gene therapy treatments for hereditary forms of deafness.
Scientists at the Boston Children’s Hospital, Massachusetts Eye and Ear and Harvard Medical School have spent several years refining a technique to repair one of the common genetic disorders that cause deafness, offering hope to millions. The genetic disorder they repaired is Usher syndrome.
Jie Zhu, Chang Ming, Xin Fu, Yaou Duan, Duc Anh Hoang, Jeffrey Rutgard, Runze Zhang, Wenqiu Wang, Rui Hou, Daniel Zhang, Edward Zhang, Charlotte Zhang, Xiaoke Hao, Wenjun Xiong, Kang Zhang.
Using the gene-editing tool CRISPR/Cas9, researchers have reprogrammed mutated rod photoreceptors to become functioning cone photoreceptors, reversing cellular degeneration and restoring visual function in two mouse models of retinitis pigmentosa.
For more information on this study: https://www.nature.com/cr/journal/vaop/ncurrent/full/cr201757a.html
Researchers from the National Institute on Deafness and Other Communication Disorders (NIDCD) and Johns Hopkins University School of Medicine showed that gene therapy was able to restore balance and hearing in genetically modified mice that mimic Usher Syndrome.
Kevin Isgrig, Jack W. Shteamer, Inna A. Belyantseva, Meghan C. Drummond, Tracy S. Fitzgerald, Sarath Vijayakumar, Sherri M. Jones, Andrew J. Griffith, Thomas B. Friedman, Lisa L. Cunningham, Wade W. Chien
For more information on this study: http://www.cell.com/molecular-therapy-family/molecular-therapy/fulltext/S1525-0016(17)30013-8
Allergan and Editas Medicine have made an alliance to work with the gene-editing CRISPR to help prevent vision deterioration.
In this study, researchers introduced CRISPR into retinal cells, tested this genome tool to remove the Nrl gene in mice and three different mouse models of retinal degeneration. By measuring gene expression and examining the retinal cells, the researchers confirmed that rods became more cone-like, as predicted which allowed for rod degeneration to be prevented or slowed.
Yu W, Mookherjee S, Chaitankar V, Hiriyanna S, Kim JW, Brooks M, Ataeijiannati Y, Sun X, Dong L, Li T, Swaroop A, Wu Z
For more information on this study: http://www.nature.com/articles/ncomms14716
Lukas D Landegger, Bifeng Pan, Charles Askew, Sarah J Wassmer, Sarah D Gluck, Alice Galvin, Ruth Taylor, Andrew Forge, Konstantina M Stankovic, Jeffrey R Holt & Luk H Vandenberghe.
Two back-to-back papers in Nature Biotechnology describe how a team at Boston Children's Hospital and Harvard Medical School developed a new vector for gene delivery and restored hearing and balance in a mouse model with the Ush1c mutation.
Bifeng Pan, Charles Askew, Alice Galvin, Selena Heman-Ackah, Yukako Asai, Artur A Indzhykulian, Francine M Jodelka, Michelle L Hastings, Jennifer J Lentz, Luk H Vandenberghe, Jeffrey R Holt& Gwenaëlle S Géléoc.
Working with a mouse model of a human mutation, Dr. Gwen Géléoc and colleagues delivered a normal copy of the USH1C gene to the inner ear soon after the mice were born, which led to robust improvements enabling profoundly deaf and dizzy mice to hear sounds at the level of whispers and recover proper balance function.
This review, published by Williams et al discusses possible gene therapy approaches for the prevention of retinal degeneration in Usher syndrome.
Researchers have discovered a holy grail of gene editing -- the ability to, for the first time, insert DNA at a target location into the non-dividing cells that make up the majority of adult organs and tissues. The technique, which the team showed was able to partially restore visual responses in blind rodents, will open new avenues for basic research and a variety of treatments, such as for retinal, heart and neurological diseases.
In the next month, scientists from RetroSense Therapeutics will inject a virus deep into the retina of legally blind human volunteers. If this works, it means that optogenetics — a revolutionary neuroscience technique using channelrhodopsin-2 and other light-activated proteins — is feasible in humans as therapy.
Astra Dinculescu, Rachel M. Stupay , Wen-Tao Deng, Frank M. Dyka, Seok-Hong Min, Sanford L. Boye, Vince A. Chiodo, Carolina E. Abrahan, Ping Zhu, Qiuhong Li, Enrica Strettoi, Elena Novelli, Kerstin Nagel-Wolfrum, Uwe Wolfrum, W. Clay Smith, William W. Hauswirth.
The ongoing challenge to develop an animal model mimicking the effects of Usher III (in particular, the loss of vision) makes it impossible for researchers to test therapies in development using conventional means. This study has important implications for designing gene therapy studies in a rational manner, to produce Clarin-1 in the correct cell type and at levels that mimic its natural production.
Massachusetts researchers have made a significant advancement toward a gene therapy treatment that would reverse deafness.
A new study questions whether gene therapy to treat Leber congenital amaurosis type 2 (LCA2) actually saves the rods and cones, the photoreceptor cells that provide vision.
According to scientists at Washington University School of Medicine in St. Louis, "Doctors may one day treat some forms of blindness by altering the genetic program of the light-sensing cells of the eye."
Three patients have been treated so far with no serious adverse events after six months. They have been allowed to proceed to delivering a larger dose to the next group of patients.
"Gene therapy 'gave me sight back'" An article from the BBC about the impact of gene therapy on patients with LCA. Similar gene therapies are planned for people with Usher.
The US Food and Drug Administration (FDA) has approved Oxford BioMedica's Investigational New Drug (IND) application for the Phase I/IIa clinical development of UshStat to treat Usher syndrome type 1B. Oxford Biometica will enroll 18 patients with Usher type 1b at the Casey Eye Institute in Portland, Oregon. The study will be lead by Dr. Richard Weleber.
University of California, Berkeley professor of neurobiology, John Flannery, is developing ways to cure genetic diseases of the retina.
Researchers at Tufts University School of Medicine and the Sackler School of Graduate Biomedical Sciences at Tufts have developed a new tool for gene therapy that significantly increases gene delivery to cells in the retina.
Oxford BioMedica, a U.K. partner of the Foundation Fighting Blindness, has received orphan drug designation from the European Medicines Agency (EMEA) for their emerging Usher syndrome gene therapy known as UshStat. The company is planning to launch a clinical trial for UshStat in 2011. The EMEA is the European Union’s regulatory agency for medicinal products. It functions similarly to the FDA in the U.S.
EU-funded scientists have succeeded in awakening dormant vision cones, an achievement that may lead to saving millions of people from going blind. The dormant cones, which normally remain in the eye even after blindness has occurred, were successfully reactivated by an international team of scientists led by the Friedrich Miescher Institute in Switzerland and the Institut de la vision in France.
Gene delivery to mitotic and postmitotic photoreceptors via compacted DNA nanoparticles results in improved phenotype in a mouse model of retinitis pigmentosa.
Unrelated to Usher syndrome, but the successful treatment of two children with ALD, a rare genetic disease, could impact gene therapy as an RP treatment. From NPR: "This marks a high point for the field of gene therapy."
A 9-year-old boy who received gene therapy for Leber congenital amaurosis (LCA) is interviewed on CBS Morning News with his parents and Dr. Stephen Rose of the Foundation Fighting Blindness. The segment includes a before and after video of him navigating a maze.
Pennsylvania researchers using gene therapy have made significant improvements in vision in 12 patients with Leber congenital amaurosis (LCA). The findings may offer hope for those with macular degeneration and retinitis pigmentosa.
