Phase I Study Shows IV Gene Therapy May Improve Macular Degeneration

MedicalResearch.com Interview with:

Prof Peter A Campochiaro MD Director, Retinal Cell and Molecular Laboratory Professor of Ophthalmology Johns Hopkins University School of Medicine Baltimore, MD

Dr. Campochiaro

Prof Peter A Campochiaro MD
Director, Retinal Cell and Molecular Laboratory
Professor of Ophthalmology
Johns Hopkins University School of Medicine
Baltimore, MD

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Patients with wet age-related macular degeneration (AMD) have increased levels of vascular endothelial growth factor (VEGF) in their eyes resulting in growth of abnormal blood vessels that leak fluid into the retina and reduce vision. The current treatment is to inject proteins that block VEGF which initially provides a very good effect, but repeated injections are needed.

Patients sometimes are unable to keep up the frequency of visits and injections needed to keep the disease quiet and over time there is often gradual loss of vision. The aim of this study was to test a new approach through which a viral vector is injected into the eye resulting in production of a protein that block VEGF in the eye reducing the need for repeated injections.

These are the major findings:

1) Intravitreous injection of an AAV2 vector expressing a protein that blocks vascular endothelial growth factor (VEGF) was safe and well-tolerated.

(2) 5 of 10 patients injected with the highest dose (2 × 10¹⁰ vector genomes) had measurable levels of the therapeutic protein in samples removed from the front of the eye- all of these patients had no or very low levels of anti-AAV2 serum antibodies and 4 of the 5 patients who did not show expression had high anti-AAV2 serum antibodies

(3) Eleven patients had fluid in or under the retina before vector injection and 6 of them showed substantial reduction of the fluid which is the desired outcome.

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New Technology May Allow Topical Delivery of Anti-VEGF Drugs For Macular Degeneration

MedicalResearch.com Interview with:

Dr Felicity de Cogan PhD</strong> Institute of Inflammation and Ageing University of Birmingham

Dr Felicity de Cogan

Dr Felicity de Cogan PhD
Institute of Inflammation and Ageing
University of Birmingham

MedicalResearch.com: What is the background for this study?

Response: The University of Birmingham has a unique approach to developing technologies. By locating chemists, engineers, biologists and clinicians in the same department it revolutionised the way research problems are solved.

Initially, Felicity de Cogan was researching cell penetrating peptides (CPP) and their uses in microbiology. However, after joining forces with Neuroscientists, Dr Lisa Hill and Professor Ann Logan at the National Institute for Health Research Surgical Reconstruction and Microbiology Research Centre (NIHR SRMRC) together with the clinicians and Vision Scientists, Dr Mei Chen and Professor Heping Xu at the Queen’s University Belfast it became evident that there was huge potential to deliver drugs in the eye. This was the start of the project and it developed rapidly from there.

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Gene Delivered By Nanoparticle System Can Potentially Cure Congenital Blindness

MedicalResearch.com Interview with:
Zheng-Rong Lu, Ph.D.

M. Frank Rudy and Margaret Domiter Rudy Professor of Biomedical Engineering
Department of Biomedical Engineering
Case Western Reserve University
Cleveland, OH 44106

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Genetic vision disorders are a major cause of severe vision loss and blindness, especially in children and young adults. Currently, there are no approved therapies to treat these types of disorders.

This study focused on one such disease known as Leber’s congenital amaurosis type 2 (LCA2). Patients with LCA2 are born with some degree of vision loss, and are often legally blind by early adulthood. LCA2 is a recessive disease caused by a mutation in one of the genes responsible for visual processing. LCA2 is a good candidate for gene therapy, and clinical trials underway to test viral vectors that deliver a healthy copy of the mutated gene into the eye have demonstrated considerable therapeutic efficacy. These trials have validated the feasibility of gene therapy to treat this disease, however viral vectors are limited by potential safety issues, complex preparation methods, and limitations on the size of genes that can be delivered.

In this study, we successfully treated LCA2 in mice for 120 days by delivering the gene responsible for LCA2 in a synthetic lipid nanoparticle instead of a viral vector. Our delivery system, called ECO, specifically targets the cells in the retinal pigmented epithelium, where the mutation behind LCA2 occurs. Our nanoparticle delivery system is easy to produce, safe, and has unlimited cargo capacity. Most important, our nanoparticle gene delivery system is a platform that can be used to deliver any gene into the retina, opening the door for safe and effective gene therapy for any genetic vision disorder.

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Study Compares Systemic Therapy vs Ocular Implant For Uveitis

MedicalResearch.com Interview with:

John H Kempen, MD, PhD Protocol Chair, MUST Trial Follow-up Study; Vice Chair, MUST Research Group Director of Epidemiology for Ophthalmology, Massachusetts Eye and Ear Harvard Medical School Editor-in-Chief, Ophthalmic Epidemiology President, Sight for Souls

Dr. Kempen

John H Kempen, MD, PhD
Protocol Chair, MUST Trial Follow-up Study; Vice Chair, MUST Research Group
Director of Epidemiology for Ophthalmology, Massachusetts Eye and Ear
Harvard Medical School
Editor-in-Chief, Ophthalmic Epidemiology
President, Sight for Souls

MedicalResearch.com: What is the background for this study?

Response: Uveitis is about the fifth leading cause of blindness in the united states.  Among types of uveitis, intermediate, posterior and panuveitis are the leading causes of blindness.  Before 2005, systemic therapy with corticosteroids—supplemented when indicated with immunosuppressive drugs (most of the time)—was the primary treatment recommended for these conditions.  With approval of the fluocinolone acetonide implant in 2005 for intermediate, posterior and panuveitis, it became unclear which of the alternative treatment approaches should be the treatment of choice.

The multicenter uveitis steroid treatment (must) trial was initiated in 2005 to directly compare the alternative treatments.  Systemic therapy was administered using high dose prednisone followed by tapering of corticosteroids to maintenance doses of 10 mg/day or less (generally 7.5 mg/day or less) or to zero; this was supplemented by immunosuppressive corticosteroid-sparing drugs in 88% of participants.  Implant therapy was done by initial quieting of the anterior chamber of the eye with topical, injected or systemic corticosteroids followed by surgical implant placement within 28 days (first eye) and 56 days (second eye if it was indicated).  After this, systemic corticosteroids and immunosuppressive drugs were tapered off.

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Number of Preschool Children With Visual Impairment Projected To Rise

MedicalResearch.com Interview with:

Rohit Varma, MD, MPH</strong> Executive Director - USC Roski Eye Institute and Dean of the Keck School of Medicine of USC

Dr. Varma

Rohit Varma, MD, MPH
Executive Director – USC Roski Eye Institute and
Dean of the Keck School of Medicine of USC

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Visual impairment in early childhood has profound impact on a child’s development. It can significantly impair development of visual, motor, and cognitive function1-3 and lead to adverse psychosocial consequences. There has been a lack of accurate data characterizing the current and expected numbers of visual impairment cases among preschool children in the United States from 2015 to 2060.

The number of preschool children with visual impairment is projected to increase by 26% in 2060. And 69% of these visual impairment will result from simple uncorrected refractive error such hyperopia and myopia, which can be prevented or treated by low-cost refractive correction.

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Age-related Macular Degeneration Underdiagnosed in Primary Care

MedicalResearch.com Interview with:

David C Neely, MD The University of Alabama at Birmingham

Dr. Neely

David C Neely, MD
The University of Alabama at Birmingham

MedicalResearch.com: What is the background for this study? What are the main
findings?

Response: This study examined the prevalence of eyes with age-related macular degeneration (AMD) in patients seen in primary eye care clinics who purportedly have normal macular health.

Approximately 25.0% of eyes deemed to be normal based on dilated eye examination by primary eye care providers had macular characteristics that indicated age-related macular degeneration. Continue reading

CRISPR Gene Editing May Lead To Cure For Retinitis Pigmentosa

MedicalResearch.com Interview with:

Kang Zhang, M.D., Ph.D.</strong> Professor of Ophthalmology Chief, Ophthalmic Genetics Founding Director, Institute for Genomic Medicine Co-Director, Biomaterials and Tissue Engineering, Institute for Engineering in Medicine Board Certification in Ophthalmology Fellowship in Vitreoretinal Disease and Surgery Guangzhou Women and Children's Medical Center Guangzhou Medical University Guangzhou China

Dr. Kang Zhang

Kang Zhang, M.D., Ph.D.
Professor of Ophthalmology
Chief, Ophthalmic Genetics
Founding Director, Institute for Genomic Medicine
Co-Director, Biomaterials and Tissue Engineering, Institute for Engineering in Medicine
Board Certification in Ophthalmology
Fellowship in Vitreoretinal Disease and Surgery
Guangzhou Women and Children’s Medical Center
Guangzhou Medical University
Guangzhou China
MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Retinitis pigmentosa is a common blinding condition characterized by mutations in rod photoreceptor specific genes, night blindness and tunnel visual with eventual loss of day vision. Since it can be caused by numerous different mutations in many genes therefore it has been difficult to provide treatment benefits to a majority of patients. Traditional gene therapy has been in a piece-meal fashion, meaning to create a therapy for a particular gene or mutation. In this paper, we describe a universal gene therapy approach using the latest gene editing technology CRISPR/CAS9 to reprogram rod photoreceptors to cone photoreceptors with reversal of RP and restoration of vision.

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Outbreak of Severe Fungal Eye Infections Linked To IV Opioid Epidemic

MedicalResearch.com Interview with:
Aubrey Tirpack, PGY3

New England Eye Center
Tufts Medical Center 

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: Intravenous drug abuse is a known risk factor for the development of endogenous fungal endophthalmitis (EFE), a severe intraocular infection cause by the seeding of mycotic organisms to the eye.

Our institution noted a marked increase in cases of EFE beginning in May 2014, which correlates to increasing rates of opioid abuse throughout the New England region. Ten patients were found to have intravenous drug abuse related EFE over the two year time period studied. The most common presenting symptoms were floaters, decreased vision, and pain. All patients were treated with systemic antifungals and nine patients underwent intravitreal antifungal injection. All patients were ambulatory at presentation and the majority were without systemic signs of infection.

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Frequency of Retinal Screening in Diabetes May Be Tailored to Individual

MedicalResearch.com Interview with:
John M. Lachin, Sc.D.
Research Professor of Biostatistics and of Epidemiology, and of Statistics
The George Washington University Biostatistics Center and
David Matthew Nathan, M.D.
Professor of Medicine, Diabetes Unit
Massachusetts General Hospital 

MedicalResearch.com: What is the background for this study?

Response: Traditional guidelines for screening for retinopathy, based on indirect evidence, call for annual examinations. The automatic annual screening for retinopathy, without considering potential risk factors for progression,  appears excessive based on the slow rate of progression through sub-clinical states of retinopathy.

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Inhaling Poppers Associated With Visual Toxicity

MedicalResearch.com Interview with:
Dr. Rebecca Rewbury
Sussex Eye Hospital
Brighton and Sussex University Hospitals Trust
Brighton, UK

MedicalResearch.com: What is the background for this study? What are the main findings?

Response: ‘Poppers’ are recreational drugs which are illegal to sell for human ingestion, but are sold under the guise of household cleaning products. Inhalation leads to a brief sense of euphoria, enhanced sexual arousal and smooth muscle relaxation. The Psychoactive Substances Act 2016 was due to outlaw poppers, but they were excluded on the basis that they do not act directly on the central nervous system.

The main constituent of poppers, isopropyl nitrite, replaced isobutyl nitrite when the latter was classified as a carcinogen in 2006. Since then, there have been several case reports of ‘poppers maculopathy.’

We noted an increase in patients presenting with central visual disturbances after using poppers and describe 12 such cases. They all demonstrated similar disruption of the photoreceptor layer on retinal imaging. Onset of symptoms was frequently linked to specific brands of poppers, with 3 people having used poppers for many years and only developing side effects on changing brand. Chemical analysis showed that these products contained isopropyl nitrite. One brand of poppers, used without side effects by one patient, contained amyl nitrite, 2-methyl butyl nitrite and isobutyl alcohol, but no isopropyl nitrite.

The outcome of poppers maculopathy varied, but following abstention, visual disturbances and retinal damage tended to improve over months, if not fully resolve. Although in some cases, symptoms and/or imaging findings were prolonged. Ongoing use of implicated brands led to persistent, but not worsening maculopathy, whereas one patient that switched back to another brand showed full recovery.

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Vascular Safety of Ranibizumab in Patients With Diabetic Macular Edema

MedicalResearch.com Interview with:

Marco A Zarbin, MD, PhD, FACS Alfonse Cinotti, MD/Lions Eye Research Professor and Chair Institute of Ophthalmology & Visual Science Rutgers-New Jersey Medical School Rutgers University Newark, NJ 0710

Dr. Zarbin

Marco A Zarbin, MD, PhD, FACS
Alfonse Cinotti, MD/Lions Eye Research
Professor and Chair
Institute of Ophthalmology & Visual Science
Rutgers-New Jersey Medical School
Rutgers University Newark, NJ 0710 

MedicalResearch.com: What is the background for this study? What are the main findings?

  1. Most large, randomized clinical trials are powered to assess the efficacy of drugs or interventions, but they usually do not enroll enough patients to accurately assess the frequency of uncommon, undesirable side effects.
  2. In order to compensate for this deficiency in trial design, investigators aggregate the results of numerous studies all of which address the same clinical question with the same (or similar) drugs/interventions to increase the power to detect uncommon side effects. These aggregate studies can be meta-analyses.
  3. Unfortunately, most meta-analyses do not have the ability to answer some critical questions such as the timing of an adverse event relative to the last exposure to the drug, nor can they compensate fully for differences among the aggregated studies in trial design, length of patient follow-up, or presence pre-existing risk factors for the side effects in question.
  4. A pooled analysis of combined clinical trials using patient level data, however, allows a more in depth analysis of side effects than study level data, which are usually used for most published meta-analyses, because patient level data allow one to incorporate the per-patient duration of exposure to treatment, adjust for imbalances in predefined baseline risk factors, and adjust for the effect of results of single studies on the overall result.

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Economic Evaluation of a Home-Based Age-Related Macular Degeneration Monitoring System

MedicalResearch.com Interview with:
John Wittenborn

Senior research scientist
NORC’s Public Health Analytics
University of Chicago

MedicalResearch.com: What is the background for this study? What are the main findings?

Response:The emergence of anti-VEGF treatment for wet-form AMD (choroidal neovascularization) has had a dramatic impact on preserving vision for many Americans. However, community-based studies show that most patients are not diagnosed with wet-form AMD until they have already lost a significant, and largely unrecoverable amount of their vision.  Early detection of wet-form AMD is key to effective treatment and the preservation of vision. The ForeseeHome telemonitoring technology provides patients with a means to check their own eyes on a daily basis to detect the earliest signs of vision loss from wet-form AMD.

This is a novel technology that has the potential to improve visual health outcomes for AMD patients.  A prior clinical trial (the AREDS-2 HOME study) demonstrated that this technology can detect wet-form AMD earlier, and with less vision loss than standard care alone. However, that is exactly where that study ended as it reported no cost information nor follow-up. Since the end of this study, the device has been cleared by the FDA and approved for reimbursement by Medicare for certain higher risk patients, but no study has yet considered the long-term implications of adoption of this technology.

In our analysis, we use a computer simulation model to essentially estimate what will come next, after patients realize earlier detection of wet-form AMD by utilizing home monitoring. Basically, we follow simulated patients from the time they begin monitoring for the rest of their lives, recording the likely impacts of home monitoring on patients’ long term outcomes including visual status, costs and quality of life.

We find that home telemonitoring among the population indicated for reimbursement by Medicare would cost $35,663 per quality adjusted life year (QALY) gained.  Medicare would expect to incur $1,312 in net budgetary costs over 10 years for each patient who initiates monitoring.  However, Medicare patients may expect to achieve lifetime net savings when accounting for the chance of avoided vision loss and its associated costs later in life.

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