Corneal Opacity

On November 7, 2024, researchers from Osaka University published a research paper entitled "Transplantation using Induced pluripotent stem cell-derived corneal epithelial cell tablets: a single-arm, open-label, first-in-human intervention study in Japan" in The internationally renowned medical journal The Lancet. This clinical study is the first in the world to use corneal epithelial cell tablets (iCEPS) derived from human induced pluripotent stem cells (iPSC) to repair corneas in patients with visual impairment due to limbal stem cell deficiency (LSCD). The results of the study show that this new type of regenerative therapy is safe and helps to improve patients' vision. The research team plans to conduct larger clinical trials to gain a deeper understanding of the treatment's efficacy. In this study, ophthalmologist Kohji Nishida and his team at Osaka University used induced pluripotent stem cell (iPSC) technology to treat limbal stem cell deficiency (LSCD). The team took blood cells from a healthy donor and reprogrammed them into IPscs, which were then transformed into a thin, transparent sheet of oval corneal epithelial cells. During the study, the research team recruited two male and two female patients, aged 39 to 72 years, all with binocular limbal stem cell deficiency (LSCD). The team first removed the scar tissue covering one of the patient's eyes, then stitched human IPSC-derived corneal epithelial cell sheets (iCEPS) and fitted the patient with flexible protective contact lenses. At the 52nd week of follow-up, secondary measures of the clinical trial showed improvement in disease staging, improved corrected distant vision, and reduced corneal opacity in all treated eyes. Although one patient experienced a slight regression in vision improvement over the one-year monitoring period, the improvement was sustained in the remaining three patients.

Oral presentation to discuss CRISPR-associated gene editing inactivating herpes virus Two poster presentations highlight the potential of EBT-104 for the treatment of HSV-1 Keratitis, demonstrating near-complete virus elimination in vitro and a significant reduction in viral shedding in vivo Company will also present data on its next generation AAV vector technology featuring an all-in-one AAV-Cas vector configuration with high gene editing activity and AAV productivity SAN FRANCISCO, April 22, 2024 (GLOBE NEWSWIRE) -- Excision BioTherapeutics Inc. (“Excision”, the “Company”), a clinical-stage biotechnology company developing CRISPR-based therapies to cure serious latent viral infectious diseases, today announced that it will present positive data from its herpes simplex virus-1 keratitis program, EBT-104, as well as an overview of a next-generation AAV delivery vector, at the American Society of Gene & Cell Therapy (ASGCT) 2024 Annual Meeting taking place May 7-11, 2024 in Baltimore, Maryland. Herpes Simplex Keratitis (HSK), caused by the infection of herpes simplex virus type 1 (HSV-1) in the cornea, is a major cause of blindness worldwide. Although current anti-HSV-1 therapies interfere with viral DNA replication, they do not eliminate HSV-1 reservoirs or prevent recurrence. CRISPR/Cas-mediated gene editing can potentially address the underlying causes of the disease by directly eliminating the latent HSV-1 reservoirs. Excision’s EBT-104 is a CRISPR-based gene therapy that is being developed as a potential cure for HSK. EBT-104 utilizes a CRISPR/Cas gene editing system to inactivate the latent HSV-1 virus. “This program is part of our mission to develop curative, CRISPR-based therapies for infectious diseases of high unmet medical need by combining our novel gene editing approach, proprietary virology platform, and our expertise in genetic engineering,” said Daniel Dornbusch, Chief Executive Officer of Excision. “The multiple presentations reflect the significant progress we have made in leveraging our comprehensive platform to identify CRISPR/Cas guide RNA pairs which effectively eliminate the HSV-1 genome DNA and viral titer in vitro and reduce viral shedding in vivo. We look forward to presenting these positive data from our EBT-104 program at this year’s ASGCT Annual Meeting.” Mr. Dornbusch continued, “In addition, we will showcase next-generation all-in-one CRISPR/Cas vector configurations with high gene editing activity, high yield, purity, and vector genome integrity. These newly engineered vectors can be manufactured at scale, demonstrating a significant increase in manufacturing yield and activity.” The details of the presentations are below: Title: CRISPR/Cas9-mediated gene editing for herpes simplex virus reduces viral reactivation in a latent rabbit keratitis model Session Type: Poster presentation Session Title: Ophthalmic and Auditory Diseases Abstract: 1633 Presenter: Nadia Amrani, Excision BioTherapeutics Location: Exhibit Hall Date/Time: May 10, 2024, 5:30 to 7:00 pm (EST) Recurrent reactivation of HSV-1 and the infection of the cornea in HSK cause corneal opacity, edema, corneal scarring, and neovascularization, which can lead to irreversible vision impairment and blindness. Currently, there is no vaccine available for HSV-1, and while nucleoside analog treatments inhibit virus replication, they cannot eliminate the infection. By targeting two critical genes in HSV-1, ICP0, and ICP27, and using the dual cut method, we induced large deletions in the viral genome preventing viral escape post-DNA repair. In Vero cells with all-in-one AAV2 vectors expressing SaCas9 and paired gRNAs nearly eliminated the viral load and titer. In vivo, using corneal scarification in a latent rabbit model of HSV-1 keratitis, our approach led to a remarkable reduction of over 60% in viral shedding from the treated rabbit eyes. Intravenous (IV) administration of AAV9 vector expressing SaCas9 and paired gRNAs in rabbits showed undetectable viral shedding in all but one rabbit following HSV-1 reactivation. Even at a low AAV dose (6E+12 VG/kg) following IV delivery, we observed substantial levels of AAV vector genomes in the trigeminal ganglia (TG), where the latent HSV-1 is located. Additionally, there was a notable decrease in HSV-1 viral DNA and LAT RNA in the TG of treated rabbits compared to the control group, indicating effective targeting of the latent HSV-1 reservoir. Title: CRISPR/CasX-Mediated Gene Editing as a Therapeutic Approach for HSV-1 Keratitis Session Type: Poster presentation Session Title: Gene Disruption and Excision Abstract: 1188 Presenter: Guoxiang Ruan, Excision BioTherapeutics Location: Exhibit Hall Date/Time: May 09, 2024, 5:30 to 7:00 pm (EST) Utilizing a high-throughput lentiviral screening method, we identified effective guide RNA pairs capable of disrupting the HSV-1 viral genome and inactivating the HSV-1 virus. We created a LentiCasX2-2xgRNA library comprised of the 440 CasX2 gRNA pairs formed from the gRNAs targeting the specific genes. Lentiviral vectors derived from this library were introduced into an HSV-1 gain-of-signal knock-in reporter HEK 293FT cell line containing the ICP27 and ICP0 consensus sequences. Successful excision of ICP27-ICP0 was facilitated by blasticidin drug selection followed by FACS harvesting. The region containing the paired CasX2 gRNAs was then PCR amplified and sequenced using Nanopore long-range sequencing. The top two CasX2 gRNA pairs from the screen were tested in Vero cells infected with the HSV-1 virus. To slow down the quick replication of the HSV-1 virus, the Vero cells were treated with valacyclovir for 24 hours post-infection followed by additional four days of culturing to allow the HSV-1 replication. Compared to the empty vector control, the two CasX2 gRNA pairs reduced HSV-1 genome DNA and viral titer by over 96%. Title: Develop Next Generation All-in-One AAV Vectors for CRISPR/Cas Gene Editing with Paired Guide RNAs Excision Program: Next Generation Vectors Session Type: Poster presentation Session Title: AAV Vectors – Virology and Vectorology Abstract: 966 Presenter: Wenwen Huo, Excision BioTherapeutics Location: Exhibit Hall Date/Time: May 09, 2024, 5:30 to 7:00 pm (EST) This study demonstrates the development of an all-in-one AAV-Cas vector configuration with high gene editing activity and AAV productivity. Fourteen dual-guide, all-in-one AAV-SaCas9 configurations were designed by modifying the composite, location, and orientation of the SaCas9 expression cassette and the expression cassettes of the two guide RNAs that target the viral long terminal repeats (LTR) and the Gag gene of HIV-1. A human beta-actin gene-derived stuffer sequence in the backbone of the AAV plasmids to minimize AAV backbone was introduced and AAV crude lysates were prepared to transduce an HIV-1 knock-in reporter cell line and examine the HIV-1 excision efficiency induced by the paired HIV-1 guide RNAs. The seven most efficient AAV-SaCas9 plasmids were further co-transfected in Hela cells along with the HIV-1 plasmid pNL4-3. Among these, two configurations exhibited the highest SaCas9 and guide RNA expression levels resulting in superior HIV-1 excision efficiency. Bioreactors test on one top AAV9-SaCas9 configuration (with an AAV vector size of 4.7 kb) and two top AAV9-PlmCasX configurations (both with an AAV vector size of 4.5 bp) demonstrated a 3-10 fold increase in AAV yield and infectious titer compared to the first generation AAV construct with over 90% PacBio sequencing reads mapped to the vector genomes and AAV plasmid backbone packaging below 1%. These findings underscore the potential of the dual-guide, optimized all-in-one AAV vectors as a versatile delivery platform for CRISPR/Cas gene editing therapeutics. Title: Selecting highly conserved and specific guide RNAs for CRISPR/CasX-mediated gene editing of the HSV-1 genome Session Type: Oral presentation Session Title: On- and Off-target Method Development Abstract: 256 Presenter: Meltem Isik, Excision BioTherapeutics Location: Ballroom 3 Date/Time: May 10, 2024, 2:00 to 2:15 pm (EST) The large size (~152kb) of the HSV-1 genome and its genetic diversity (1–4% variation in nucleotide identity between viral genomes) pose significant challenges for genomics understanding. Ongoing research uncovers new genotypes, underscoring the importance of considering HSV-1 genetic diversity in selecting lead guides for therapeutic genome editing. In this study, we used the CRISPR/CasX gene editing system to inactivate the latent HSV-1 virus by co-targeting two essential HSV-1 genes, ICP0 and ICP27. To perform guide design, we built a Herpersviridae family CDS database to select highly conserved guide RNAs. 22 PlmCasX guide RNAs targeting ICP0 and 20 PlmCasX guide RNAs targeting ICP27 were found with a perfect sequence match in over 70% of HSV-1 strains. They were also found with perfect match to the consensus sequences of ICP0 and ICP27. The 440 guide RNA pairs formed with these 42 PlmCasX guide RNAs were tested in tissue culture for DNA excision efficiency. The most efficacious guide RNA pairs were evaluated for possible off-target editing using homology-dependent and homology-independent methods. The results were analyzed using in-house developed bioinformatics pipelines and targeted amplicon sequencing. The off-target assessment identified several highly specific PlmCasX guide RNAs that showed no detectable off-target editing activity. About Excision BioTherapeutics, Inc. Excision BioTherapeutics, Inc. develops CRISPR-based medicines as potential cures for serious viral latent infectious diseases. The Company’s proprietary, multiplexed gene editing platform unites CRISPR technologies with a novel gene editing approach which demonstrated the ability to stop viral replication. Excision’s pipeline targets large, underserved markets including herpes simplex virus (HSV-1 keratitis), hepatitis B virus (HBV), and human immunodeficiency virus-1 (HIV-1). Excision’s foundational technologies were developed in the laboratories of Dr. Kamel Khalili at Temple University and Dr. Jennifer Doudna at the University of California, Berkeley. For more information, please visit Contact: John Fraunces LifeSci Advisors 917-355-2395 jfraunces@lifesciadvisors.com

Gene therapy being developed as a one-time treatment to address the underlying cause of the disease by inserting a functional copy of the human IDUA gene into a patient’s own hematopoietic stem cells HURCULES study to enroll 40 patients at clinical sites across the U.S. and Europe TOKYO, LONDON and BOSTON, Feb. 05, 2024 (GLOBE NEWSWIRE) -- Orchard Therapeutics, recently acquired by Kyowa Kirin with the goal of accelerating the delivery of new gene therapies to patients around the globe, today announced the first patient has been randomized at the M Health Fairview Masonic Children’s Hospital in a registrational trial evaluating the efficacy and safety of OTL-203, an investigational hematopoietic stem cell (HSC) gene therapy, in patients with the Hurler subtype of mucopolysaccharidosis type I (MPS-IH). The trial, referred to as HURCULES, compares treatment with OTL-203 to standard of care with allogeneic hematopoietic stem cell transplant (HSCT), and is expected to enroll 40 MPS-IH patients at sites across the U.S. and Europe. MPS-I is a rare, inherited neurometabolic disease caused by a deficiency of the alpha-L-iduronidase (IDUA) lysosomal enzyme resulting in the accumulation of glycosaminoglycans (GAGs) in multiple organs, including the musculoskeletal and central nervous systems, as well as the heart, eyes, and ears. It is estimated to occur globally in 1 in 100,000 live births. Approximately 60 percent of children born with MPS-I have the most severe subtype, MPS-IH, also called Hurler syndrome, and rarely live past the age of 10 when untreated. Current treatment options for MPS-IH include allogeneic hematopoietic stem cell transplant (HSCT) and enzyme replacement therapy (ERT), both of which have significant limitations. “This is a substantial milestone in the development of OTL-203 as we work toward bringing an important new treatment option to children with MPS-IH and their families,” said Leslie Meltzer, Ph.D., chief medical officer of Orchard Therapeutics. “Previously reported results from an earlier proof-of-concept study in patients showed robust metabolic correction, continued cognitive, motor, and physical development, as well as early improvements in skeletal, ocular and auditory health demonstrating that one-time treatment with OTL-203 has the potential to positively impact a broad range of clinical manifestations not fully addressed by the current standard of care.” In an earlier single-center proof-of-concept (PoC) study, eight patients diagnosed with MPS-IH were treated at Ospedale San Raffaele in Milan, Italy with investigational OTL-203 between July 2018 and December 2019. Throughout the follow-up period, a total of 26 serious adverse events (SAEs) were observed. The events were related to known complications of MPS-IH already present prior to treatment, protocol procedures or general illnesses of childhood, and all have resolved. One patient experienced an acute hypersensitivity reaction that was considered probably related to HSC gene therapy. OTL-203 has received Fast Track and Rare Pediatric Disease (RPD) designations from the U.S. Food and Drug Administration (FDA), as well as priority medicines (PRIME) status from the European Medicines Agency (EMA). The program was originated by, and initially developed in partnership with, the San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) in Milan, Italy. “The complications associated with MPS-IH have a detrimental impact on patients’ quality of life, and while transplantation may help improve outcomes, it is associated with significant morbidity and mortality,” said Paul Orchard, M.D., a study investigator and professor in the Division of Pediatric Blood and Marrow Transplantation and Cellular Therapy Program at the University of Minnesota Medical School. “New options are needed to better address some of the more severe symptoms of the disease, such as neurocognitive function, growth and other skeletal issues. We look forward to working with the team at Orchard Therapeutics and other clinical sites around the world to facilitate enrollment in this study and characterize the potential clinical impact of OTL-203 on MPS-IH.” Currently, the University of Minnesota is actively recruiting patients with additional trial sites expected to begin recruitment in the coming months. Summary of Previous OTL-203 Clinical Results Interim results from the earlier PoC study published in The New England Journal of Medicine showed all patients had supraphysiological IDUA enzyme activity with an associated sustained decrease in GAG levels and stable cognitive performance post-treatment. In addition, all participants had progressed along expected growth percentiles of healthy children and exhibited longitudinal growth that was considered within the normal range adjusted for age and gender. In subsequent follow-up, study investigators have observed progressive acquisition of fine and gross motor skills, as well as evidence of continued growth within normal range and improvements in skeletal health with a median follow-up of 3.78 years (range: 3.14 to 4.58 years) as of May 2023. In addition, Dr. Maria Ester Bernardo, clinical coordinator, pediatric clinical research unit at SR-TIGET and the principal investigator of the PoC study, detailed the first findings on other treatment outcomes, including ocular (eye) symptoms and auditory (hearing) function at the European Society of Cell and Gene Therapy (ESGCT) 30th Annual Congress. The presentation outlined favorable results for disease manifestations not fully addressed by the current standard of care and further highlights the potential of genetically repaired HSCs to migrate into and correct abnormalities in multiple tissues and organs. Throughout the PoC study, treatment with OTL-203 has been generally well-tolerated with a safety profile consistent with the selected conditioning regimen. The viral vector integration profile was comparable with other Orchard Therapeutics lentiviral-based HSC gene therapy studies, and all participants had a stable and highly polyclonal repertoire. As part of the study, ERT was discontinued at least three weeks prior to any patient receiving gene therapy, and none of those patients needed to re-start ERT post-treatment. Patients who entered the study with anti-IDUA antibodies present because of prior ERT treatment were no longer antibody positive within two months of treatment with OTL-203. About the HURCULES StudyHURCULES—a study name that combines the target indication HURler syndrome and HerCULES, the classical mythological character—is a multi-center, randomized, active controlled clinical trial designed to evaluate the efficacy and safety of OTL-203 in patients with MPS-IH compared to standard of care with allogeneic HSCT. A total of 40 patients with a confirmed diagnosis of MPS-IH who meet the study inclusion criteria are being randomized 1:1 to receive either OTL-203 or allogeneic HSCT. The study is powered to demonstrate superiority of OTL-203 over allogeneic HSCT. The primary endpoint, which will be measured at two years post-treatment, comprises a composite of clinically meaningful outcomes, including death, the need for rescue transplant, treatment failure, immunological complications, as well as severe cognitive and/or growth impairment. Secondary endpoints include biochemical markers, additional clinical assessments, as well as safety and tolerability. The company expects to activate six sites in the United States and Europe. For more information, please visit www.clinicaltrials.gov (NCT06149403). About MPS-IMucopolysaccharidosis type I (MPS-I) is a rare, inherited neurometabolic disease caused by a deficiency of the alpha-L-iduronidase (IDUA) lysosomal enzyme, which is required to break down sugar molecules called glycosaminoglycans (GAGs). The accumulation of GAGs across multiple organ systems results in multiple symptomatic manifestations of the disease including severe neurocognitive impairment, skeletal deformities, cardiovascular and pulmonary complications, impaired motor function, loss of hearing and corneal clouding. MPS-I occurs at an overall estimated frequency of one in every 100,000 live births. There are three subtypes of MPS-I. Approximately 60 percent of children born with MPS-I have the most severe subtype, called Hurler syndrome (MPS-IH), and rarely live past the age of 10 when untreated. Treatment options for MPS-I include hematopoietic stem cell transplant and enzyme replacement therapy, both of which have limitations, such as inadequate impact on some of the more severe manifestations of disease, as well as significant morbidity and mortality. At present, Newborn Screening (NBS) for MPS-I has been established in multiple geographies, including the United States and Europe. About OTL-203OTL-203 is an investigational hematopoietic stem cell gene therapy being developed for the treatment of MPS-IH. It uses a modified virus to insert a functional copy of the human IDUA gene into a patient’s cells. OTL-203 was originated by, and initially developed in partnership with, the San Raffaele Telethon Institute for Gene Therapy in Milan, Italy. OTL-203 has received Rare Pediatric Disease (RPD) and Fast Track designations from the U.S. FDA, as well as priority medicines (PRIME) status from the EMA. About Orchard TherapeuticsOrchard Therapeutics, a Kyowa Kirin company, is a global gene therapy leader focused on ending the devastation caused by genetic and other severe diseases by discovering, developing, and commercializing new treatments that tap into the curative potential of hematopoietic stem cell (HSC) gene therapy. In this approach, a patient’s own blood stem cells are genetically modified outside of the body and then reinserted, with the goal of correcting the underlying cause of disease with a single treatment. Founded in 2015, Orchard’s roots go back to some of the first research and clinical developments involving HSC gene therapy. Our team has played a central role in the evolution of this technology from a promising scientific idea to a potentially life-transforming reality. Today, as a vital part of Kyowa Kirin’s global business, Orchard continuing to advance a pipeline of HSC gene therapies designed to address serious diseases where the burden is immense for patients, families and society and current treatment options are limited or do not exist. For more information, please visit www.orchard-tx.com. About Kyowa KirinKyowa Kirin aims to discover novel medicines with life-changing value. As a Japan-based Global Specialty Pharmaceutical Company, we have invested in drug discovery and biotechnology innovation for more than 70 years and are currently working to engineer the next generation of antibodies and cell and gene therapies with the potential to help patients affected by a severe or rare disease. A shared commitment to our values, to sustainable growth, and to making people smile unites us across our four regions – Japan, Asia Pacific, North America, and EMEA/International. You can learn more about the business of Kyowa Kirin at: https://www.kyowakirin.com.