Dozens of young patients will be among the first in Canada to benefit from this treatment, which improves vision and slows the progressive loss of vision.

Source: MUHC

Restoring vision to people with inherited retinal dystrophies through a new gene therapy surgery will soon be possible at the McGill University Health Centre (MUHC), thanks to the long-term work of Dr. Robert K. Koenekoop, Director of Pediatric Ophthalmology at the Montreal Children’s Hospital (MCH) of the MUHC. Health Canada has approved the Luxturna® treatment, the first gene therapy in Canada for the treatment of patients with inherited retinal dystrophies caused by the RPE65 gene mutation, such as Leber congenital amaurosis and retinitis pigmentosa. This is the first treatment for these devastating conditions; it represents a giant step forward in the field of personalized medicine. It will not only allow these individuals to regain some of their vision, but also to recover their autonomy.

Dr. Koenekoop, who is also a Professor of Pediatric Surgery, Human Genetics and Ophthalmology at McGill University , states that this milestone comes after more than 20 years of gene therapy research. Dr. Koenekoop’s research has been supported by the Montreal Children’s Hospital Foundation and Fighting Blindness Canada for over 20 years.

Inherited retinal diseases are common conditions that affect 1 in 2,000 people. Incurable and debilitating, they cause a progressive loss of vision and visual field and a loss of autonomy in those affected. The services currently offered to patients – mainly, follow-up of the progression of the disease, psychological support, low vision and mobility assistance and visual rehabilitation – do not include therapeutic treatment and do not address the underlying causes of the disease. These important services will remain to be crucial as they will help adjust the treated patients to their new vision.

The results of human clinical trials, that took place from 2005 to 2019, show that Luxturna® significantly improves vision, clarity, night vision and can slow or even stop the progressive loss of vision in patients with inherited retinal dystrophies due to the defective RPE65 gene. Dr. Koenekoop is following nearly 40 patients at the MCH who

would be potential candidates for this new gene-specific treatment. In Canada, close to 115 patients could currently benefit from this new treatment.

Luxturna® is a unique treatment that consists of a single surgical injection in which a functional copy of the gene is directly introduced into the patient’s retinal cells in order to replace the defective gene. The patient must first undergo a screening test to confirm the presence of the RPE65 mutations in addition to having enough viable retinal cells. The functional gene will produce the protein that was previously deficient. This protein allows the retinal cells to regenerate and become functional, meaning they will be able to capture light again.

“As a treating physician and researcher dedicated to finding solutions and treatments for inherited retinal dystrophies, I am very enthusiastic about the hope Luxturna® brings to patients with confirmed RPE65 mutation-associated retinal dystrophy who face potentially total blindness. The gradual loss of sight in young children and adults is devastating to all aspects of their lives as their independence is reduced and dependency on a caregiver increases. There is finally a promising future ahead, as I predict more and more gene-based and other treatments for IRD patients,” says Dr. Robert Koenekoop. “Gene editing, three more gene therapies, stem cells and drugs are well advanced in the research-to-bedside pipeline”, he adds.

The work of multidisciplinary teams

This treatment is made possible through the collaboration of multidisciplinary teams from The Montreal Children’s Hospital in association with Hôpital Maisonneuve-Rosemont in Montreal, The Hospital for Sick Children (SickKids) in partnership with Sunnybrook Health Sciences Centre, in Ontario, as well as Novartis Pharmaceuticals Canada Inc., who as part of their commitment to Cell and Gene Therapy, is bringing Luxturna to Canada.

Luxturna is the first gene therapy to be approved by the Food and Drug Administration (FDA) and has been available in the United States since 2017.

About the disease

Inherited retinal diseases are a group of conditions that cause retinal degeneration leading to complete blindness in affected individuals. They cause a loss of sensitivity to light, sharpness, clarity and reduced peripheral vision. They can be caused by genetic mutations in more than 270 genes, including RPE65.

About Dr. Robert K. Koenekoop

Dr. Koenekoop works at the Montreal Children’s Hospital and has 25 years of experience as a clinician-scientist. He is a Senior Scientist in the Child Health and Human Development Program at the Research Institute of the MUHC. His research focuses on identifying the genes that cause inherited retinal dystrophies and matching their treatments. Currently, Dr. Koenekoop is conducting numerous human clinical trials for the treatment of inherited retinal diseases and is a strong advocate for patients and the implementation of these sight-saving treatments in Canada. He is part of an exciting new group of gene therapists, researchers and clinicians at the Montreal Children’s Hospital and the Research Institute of the MUHC. This group, led by Drs John J. Mitchell, Geneviève Bernard, Maryam Oskoui, Nancy Braverman, Sam Daniel and others, is studying and performing gene therapies in children with genetic diseases such as Lysosomal storage diseases (Hunter and Hurler syndrome, for example), neurodegenerations, spinal degeneration, peroxisomal disorders, hearing loss and more. This group is in the planning phase of establishing a Montreal Children’s Gene Therapy Center of Excellence, supported by the Montreal Children’s Hospital Foundation through a capital campaign.



October 15 2020