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At Defeat Duchenne Canada, we know that research is the only way to find a cure and improve care for those living with Duchenne muscular dystrophy. 

Since 1995, Defeat Duchenne Canada has believed in developing strong partnerships with academics and clinicians to fund the most promising research. Through their determination and love for their son, Jesse, the Davidson family built a legacy endowment fund that has granted millions of dollars to research projects worldwide. 

While science is the method behind our mission, there would be no progress without people like you.

Donations from our community, and the stories behind them, are the only reasons we have been able to fund the life-changing research milestones you will learn more about below.

To date, Defeat Duchenne Canada has funded $17.73 million across 61 research projects around the world.

Funded Research Projects

Funded Projects in 2023

Dr. Ward

Dr. Leanne Ward

Children’s Hospital of Eastern Ontario (CHEO) – Ottawa, ON

Two-Year Fellowship Grant in Partnership with Parent Project Muscular Dystrophy (PPMD)

Full Professor, Medical Director of the CHEO Bone Health Clinic, Scientific Director of the Ottawa Pediatric Bone Health Research Group

Research Chair in Pediatric Bone Health, University of Ottawa

Pediatric Endocrinologist, Division of Endocrinology and Metabolism, CHEO

Dr. Ward’s research program is dedicated to the study of bone development and the diagnosis and treatment of bone disorders in children, including osteoporosis and rickets. She has been the principal investigator of the “STOPP” research program (STeroid-induced Osteoporosis in the Pediatric Population) since 2003, a pan-Canadian project funded by the Canadian Institutes of Health Research to evaluate the effect of glucocorticoids on bone health in children with chronic illnesses. This multi-centre longitudinal research program has unveiled the natural history of osteoporotic fractures in children with steroid-treated disorders, including the clinical hallmark of this disorder in children, vertebral fractures. The results of the STOPP Consortium’s work under Dr. Ward’s leadership have played a major role in informing the approach to diagnosing steroid-induced osteoporosis in children, monitoring those at risk, and identifying children in need of osteoporosis prevention and intervention.

Dr. Ward is actively involved in and leads a number of clinical trials for children with osteogenesis imperfecta, rickets (including X-linked hypophosphatemia), and chronic illness osteoporosis, including Duchenne muscular dystrophy (DMD). She has served as an endocrinology and bone health advisor to various international organizations, including the Centres for Disease Control Clinical Care Guidelines for DMD, the International Late Effects of Childhood Cancer Guideline Harmonization Group, the International Society for Clinical Densitometry and the International Conference on Children’s Bone Health. She is the founder and chair of the Canadian Pediatric Bone Health Working Group and a frequently invited speaker at international bone and endocrinology conferences.

Dr. Ward has published over 130 original peer-reviewed manuscripts, book chapters and reports and has received awards for her work in pediatric bone health, including a Canadian Child Health Clinician Scientist Career Development Award, a Canadian Institutes for Health Research New Investigator Award, a Canadian Child Health Clinician Scientist Career Enhancement Award, and two, five-year Research Chairs in Pediatric Bone Health (University of Ottawa, 2010 and 2015).

In 2019, Dr. Ward was named a Fellow of the American Society of Bone and Mineral Research, an award in recognition of significant contributions to bone and mineral science.

Defeat Duchenne Canada, Canada’s leading charity fighting to defeat Duchenne, and Parent Project Muscular Dystrophy (PPMD), a US nonprofit organization leading the fight to end Duchenne muscular dystrophy (Duchenne), have announced a collaborative research award of $300,000 (USD) in support of two Clinical Fellowships in Duchenne Endocrinology and Bone Fragility.

The three-year award will sponsor the extended fellowship of Dr. Kim Phung, as well as new fellow Dr. Rana Halloun, under the guidance of Dr. Leanne Ward, Professor of Pediatrics and Research Chair in Pediatric Bone Disorders at the University of Ottawa.

Dr. Cohn

Dr. Ronald Cohn

The Hospital for Sick Children (SickKids) – Toronto, ON

“Combinatorial CRISPR/Cas9-mediated duplication removal and glucocorticoid treatment in a humanized mouse model of a DMD duplication”

Dr. Ronald Cohn has served as President and CEO of the Hospital for Sick Children (SickKids) in Toronto, Canada, since May 1, 2019. Dr. Cohn joined SickKids in September 2012 as the Chief of the Division of Clinical and Metabolic Genetics, Co-Director of the Centre for Genetic Medicine, and Senior Scientist at the SickKids Research Institute. He became the Inaugural Women’s Auxiliary Chair in Clinical and Metabolic Genetics in April of 2013 and joined the Department of Molecular Genetics at the University of Toronto. In 2016, he was appointed Chief of Paediatrics at SickKids and Chair of Paediatrics at The University of Toronto.

Dr. Cohn received his medical degree from the University of Essen, Germany. After his postdoctoral fellowship at the Howard Hughes Medical Institute in the laboratory of Dr. Kevin Campbell, he moved to Baltimore, where he was the first combined resident in pediatrics and genetics at Johns Hopkins University. He subsequently joined the faculty of the McKusick-Nathans Institute of Genetic Medicine at Johns Hopkins, where he became the director of the world’s first multidisciplinary centre for Hypotonia, which has earned national and international recognition.

Dr. Cohn was also the director of the medical genetics residency program at Johns Hopkins. He has received numerous awards, including the David M. Kamsler Award for outstanding compassionate and expert care of pediatric patients in 2004, the First Annual Harvard-Partners Center for Genetics and Genomics Award in Medical in 2006, and the NIH Young Innovator Award in 2008.

Over the last few years, Dr. Cohn has developed an interest in applying the concept of Precision Child Health to the care of children. His own research focuses on implementing genome editing technologies for the treatment of neurogenetic disorders.

Duchenne muscular dystrophy (DMD) is a condition that causes muscles to weaken and deteriorate over time. Children with DMD lose their ability to walk early in life and often face life-threatening breathing and heart issues in their 20s-30s. Existing treatments only manage symptoms, not the root cause, which is due to errors in the dystrophin gene responsible for muscle strength.

There is an urgent need for better treatments that can stop or reverse DMD. Recent advances in gene editing technology offer hope for treating genetic diseases like DMD. One breakthrough is CRISPR/Cas9, a tool that can cut and edit DNA at specific locations, providing a chance to fix genetic errors.

Dr. Cohn’s research team developed a CRISPR/Cas9-based approach to fix a specific type of error called duplications in the dystrophin gene, a common cause of DMD. They successfully removed these duplications, which significantly improved DMD symptoms in mice.

Before progressing to human trials, they need to verify the treatment’s effectiveness in a mouse model with a human version of the dystrophin gene. This is necessary because CRISPR/Cas9 targets specific DNA sequences, and human and mouse sequences differ enough that a human-designed therapy wouldn’t work well in mice.

Their plan involves creating “humanized” mouse models of DMD with duplication mutations in the dystrophin gene. They’ll test the efficacy of our duplication removal strategy in these mice.

Since most DMD patients are treated with steroids to manage symptoms, they’ll also pre-treat our mice with steroids before administering the CRISPR/Cas9 duplication removal therapy. This approach helps create an experimental setup that more closely resembles real-world conditions faced by DMD patients.

By using a steroid-treated humanized DMD mouse model, their experiment aims to provide a more accurate representation of the disease. They’re optimistic that this project could be a significant step forward in developing a CRISPR/Cas9-based treatment for DMD, paving the way for the first clinical trials using gene editing technology to treat this debilitating disease.

Dr. Chang

Dr. Natasha Chang

McGill University – Montreal, QC

“Inducing stress granule formation in muscle stem cells to treat DMD”

Dr. Natasha Chang received her Ph.D. in Biochemistry from McGill University and pursued her postdoctoral fellowship at the Ottawa Hospital Research Institute.

Dr. Chang joined McGill as an Assistant Professor in the Department of Biochemistry in 2019. Research in the Chang laboratory focuses on understanding the molecular signalling mechanisms that regulate muscle stem cell function and how these pathways are altered in the context of muscle degenerative disease and muscle cancer. The ultimate goal for Dr. Chang’s research team is to identify molecular targets to improve endogenous stem cell regenerative capacity as well as strategies to improve stem cell transplantation therapy. 

Duchenne muscular dystrophy (DMD) is a devastating degenerative muscle disease that affects 1 in every 5,000 Canadian male births. Despite research efforts to understand the cause and progression of the disease, there still remains no effective cure for DMD.

Emerging studies have found that muscle stem cells, which are adult stem cells that reside within the muscle tissue, are affected in DMD. In DMD, they do not function the same as normal healthy muscle stem cells, and their dysfunction plays a role in disease progression as they cannot efficiently contribute to the repair or maintenance of muscle. Her research program aims to study these stem cells in DMD and to understand how they are dysfunctional. Importantly, their goal is to correct their dysfunction.

In this research project, Dr. Chang and her team are pursuing a strategy to help restore the ability of DMD muscle stem cells to help repair muscle. The findings from this work will provide a strong foundation for boosting muscle stem cells as a valid treatment strategy for patients with DMD.

Dr. Tremblay

Dr. Jacques Tremblay

Laval University – Quebec City, QC

“In vivo correction by CRISPR PRIME editing of mutations responsible for Duchenne Muscular Dystrophy”

Jacques P. Tremblay, Ph.D., is a professor in the Department of Molecular Medicine at Laval University. He has worked on cell and gene therapies for hereditary diseases (particularly Duchenne Muscular Dystrophy) since 1987. He has worked mainly on the transplantation of myoblasts derived from a healthy donor as a treatment for Duchenne Muscular dystrophy.

In collaboration with Dr. Jean-Pierre Bouchard, he has conducted a phase I clinical trial of that treatment. He received the Best Researcher in Canada award presented by Muscular Dystrophy Canada in 2004. In 2005, the Royal College of Physicians and Surgeons of Canada and the Canadian Society for Clinical Investigation presented the Henry Friesen Award.

In 2020, in collaboration with Dr. Craig Campbell, he initiated a phase II clinical trial of myoblast transplantation; unfortunately, this trial was discontinued because of the COVID-19 pandemic.

He is currently using the Prime editing technology (derived from the CRISPR/Cas9 technology) to correct mutations responsible for various hereditary diseases, including Duchenne Muscular Dystrophy.

There are two main types of mutations responsible for DMD:

Type 1) deletion of one or several exons with a total number of coding nucleotides which is not a multiple of 3 and,

Type 2) the change of only a few nucleotides resulting in a stop codon.

Both mutation types result in the production of only the beginning of the dystrophin protein, which is not functional.

Prime editing permits to modify a targeted pair of nucleotides, insert or delete several nucleotide pairs. Dr. Tremblay and his team have already used a new gene modification technology called “CRISPR-Cas9 Prime editing” to correct type 1 of mutations in cells in culture. So far, they have used the Prime editing technique to correct nine different DMD point mutations. In the present grant project, they aim to increase the frequency of correction of point mutations in DMD myoblasts by using improved Prime editing agents called PEmax and epegRNA. They will also correct point mutations in four different mouse models of DMD.

They have some preliminary results on the correction of type 2 mutations in cells in culture. During the present project, they aim to use Prime editing to restore the normal reading frame of the DMD gene in myoblasts containing an exon deletion, inducing a translation frameshift. They will also correct this type of mutation in a mouse model.

They will also verify whether the correction of mutations by prime editing induces mutation of genes other than the DMD gene.

This project’s main challenge will be delivering the Prime editing technology components to most muscles and the heart, i.e., the SpCas9 nickase fused with a reverse transcriptase and an epegRNA. Dr. Tremblay and his team will investigate four delivery methods: Adeno Associated Virus (AAV), Lipid Nano Particles (LNPs), Extra-cellular Vesicles (EVs) and Virus-Like Particles (VLPs).   

Dr. Aoki and Dr. Sathyaprakash

Dr. Yoshitsugu Aoki & Dr. Chaitra Sathyaprakash

National Center of Neurology and Psychiatry – Tokyo, Japan

“Patient iPSC-derived brain organoids as a model for cognitive phenotypes of Duchenne muscular dystrophy”

Yoshitsugu Aoki is a highly accomplished neurologist and researcher. He graduated from the University of Tohoku in 2001 and had a distinguished career in clinical neurology. In 2008, he became a consultant, and in 2011, he earned a PhD from Tokyo Medical and Dental University Graduate School. In 2012, he joined Prof. Matthew Wood’s laboratory at Oxford University, which focused on developing oligonucleotide treatments for neuromuscular diseases. The Royal Society of the UK recognized Dr. Aoki’s work in 2013 for Exceptional Promise.

Currently, Dr. Aoki is the head of the Department of Molecular Therapy. He is also an Adjunct Professor at several prestigious universities in Japan. Dr. Aoki’s research primarily focuses on gene therapy for neuromuscular diseases such as Duchenne muscular dystrophy. He places a strong emphasis on mRNA splicing modulation using antisense oligonucleotides. Dr. Aoki’s notable contributions to the field include the development of VILTEPSO®, an antisense oligonucleotide-based drug that underscores his dedication to advancing therapeutic options for rare diseases. As the Japan Rare Disease Consortium leader, Dr. Aoki is committed to fostering innovation and collaboration to overcome neuromuscular diseases.

Dr Chaitra Sathyaprakash has been a postdoctoral research fellow at the National Center of Neurology and Psychiatry since 2021, working on setting up human 3D model brain organoids to model cognitive phenotypes of Duchenne muscular dystrophy.

Dr. Sathyaprakash has a background in Biochemistry (BSc) from Imperial College London (2013), later specializing in Neuroscience (MSc) at University College London (2014). She worked briefly as a research assistant in RNA therapeutics at the University of Oxford with Prof Matthew Wood and Dr. Yoshitsugu Aoki, analyzing human models of motor neuron disease and linked extracellular vesicle phenotypes. From 2015 to 2019, she was awarded the Barry Bastin Fellowship (Motor Neuron Disease Association) to undertake a DPhil with Prof Kevin Talbot (Nuffield Department of Clinical Neuroscience, University of Oxford), working on transcriptomic analysis of amyotrophic lateral sclerosis iPSC-motor neuron models. For a short time, she worked with Prof Tara Spires-Jones on an Alzheimer’s Disease project, assessing synaptic phenotypes of iPSC-cortical neuron models of dementia.

Throughout her academic career, Dr. Sathyaprakash has had a strong interest in furthering our knowledge of early phenotypes of neurodegenerative and neuromuscular disease, in particular, using human-derived models to improve precision medicine-driven therapeutics and increasing the potential of larger preclinical therapeutic studies in a human-specific model. Her current work in human brain organoid models of DMD aims to improve our understanding of the early synaptic changes in the brain driven by the loss of brain-specific alternatively spliced DMD isoforms, leading to early onset autism spectrum disorder and memory impairment.

Duchenne muscular dystrophy (DMD) is a disease that affects boys and causes muscle weakness. Additionally, around one-third of boys with DMD are diagnosed with brain-related disorders early in life, including autism and memory difficulties. However, we do not clearly understand the processes that cause them.

The DMD gene that makes muscle dystrophin also makes smaller proteins in the brain, which are lost in patients. These proteins exist at synapses, where electrical impulses are produced for normal brain function. The loss of important proteins at synapses, both before and after birth, leads to an imbalance of electrical activity, causing various disorders. Thus, we propose making 3D ‘mini-brains’ using stem cells made from urine-derived cells, kindly donated by boys with DMD.

These ‘mini-brains’ better capture human processes compared to commonly used mouse models, whose brain chemistry and structure is very different. We aim to (1) pin down the timepoint in ‘mini-brain’ growth when short dystrophins are most important and (2) understand the processes at synapses that change when shorter dystrophin proteins are lost. This ethical, human-relevant model is also suitable for testing treatments. We hope to contribute to finding treatments for both muscle weakness and brain-related disorders in DMD patients, helping them live more independent lives.

Funded Projects in 2022

Dr. Michael Rudnicki

Dr. Michael Rudnicki

Ottawa Hospital Research Institute  – Ottawa, ON
“Systemic Delivery of Wnt7a for Treating Duchenne Muscular Dystrophy”

Michael Rudnicki is a Senior Scientist and the Director of the Regenerative Medicine Program and the Sprott Centre for Stem Cell Research at the Ottawa Hospital Research Institute. He is Professor in the Department of Medicine at the University of Ottawa. Dr. Rudnicki is CEO and Scientific Director of the Canadian Stem Cell Network (SCN). Dr. Rudnicki’s achievements have been recognized by numerous honors including being named an Officer of the Order of Canada, a Fellow of the Royal Society (London), a Fellow of the Royal Society of Canada, and International Research Scholar of the Howard Hughes Medical Institute for two consecutive terms. He has been a founder in several spin-off biotechnology companies including Satellos Bioscience.

Dr. Rudnicki is an internationally recognized thought leader in molecular genetics and regenerative medicine whose research has transformed our understanding of muscle development and regeneration and has fueled the development of novel stem cell-based approaches to treat muscular dystrophy. His work is consistently published in top journals including Cell, Nature, Nature Cell Biology, Nature Medicine, and Cell Stem Cell. He holds major research grants from NIH, CIHR, SCN, and several health charities. Dr. Rudnicki is a member of the editorial boards of Cell Stem Cell, Journal of Cell Biology, and Stem Cells. He is a founding Co-Editor-in-Chief of the journal Skeletal Muscle. Dr, Rudnicki has also organized many international research conferences and was a founding Director of the Society for Muscle Biology.

For the past 17 years, Dr. Rudnicki has led the Stem Cell Network (SCN), a transformative initiative involving over 175 investigators across Canada. As Scientific Director of the SCN, he has forged a national community that transformed stem cell research in Canada and brought research to the point where regenerative medicine is impacting clinical practice.

Dr. Rudnicki has discovered a protein called Wnt7a as a potential treatment for Duchenne due to its ability to repair muscle damage. He intends to work on delivering this protein through the circulation so it can reach all muscles in the body. His lab is investigating exosomes, small vesicles found naturally in our bodies responsible for delivering information between cells.

Through this funded project, this team will engineer new versions of exosomes carrying Wnt7a to provide this therapy to muscle cells with the hopes of stimulating the muscle’s own capacity for regeneration and growth regardless of mutation.

Dr. Guy Odom

Dr. Guy Odom

University of Washington – Seattle, WA
“Phenotypic screening of deimmunized DMD gene therapy vectors”

Dr. Guy L. Odom is an Associate Professor in the Department of Neurology at the University of Washington School of Medicine. He received a M.Sc. degree in microbiology, immunology and parasitology at the Louisiana State Health Science Center, New Orleans, LA in 1998, and a Ph.D. in molecular & cell biology at Tulane University in 2005 under the mentorship of Dr. Prescott Deininger with a focus on genomic instability and mobile DNA mechanisms.

Dr. Odom has long had ‘gene therapy’ on the radar, in 1996 as a graduate student he co-authored his first publication in the field.  The overall premise of this study was to use transient CD4+ immune suppression to permit re-administration of E1-adenoviral vectors in mice.  Following graduate school in 2005, Dr. Odom transitioned to the pacific northwest having accepted a post-doctoral fellow position at the University of Washington (Seattle), in the laboratory of Dr. Jeffrey S. Chamberlain where he emersed himself in the field of Duchenne Muscular Dystrophy (DMD) and viral vector gene transfer technologies having received funding from the NIH and the MDA.

Dr. Odom’s current research continues to evaluate DMD pathogenesis and novel therapeutics for DMD, striving to develop a better understanding of the disease progression, inherent responses at the cellular and genomic levels, and the development of improved gene therapy technologies.  Recently deimmunization has emerged as a technology that combines computational protein redesign methods with immune epitope data to engineer vectorized biologics with highly reduced immune liabilities.  This research has included the use of physiological measurements at the cellular, single muscle, or whole organismal levels by incorporating sonography, electrophysiological and magnetic resonance imaging techniques.  Other interests include muscle stem cell biology, transcriptional regulation, metabolomics, proteomics and combinatorial gene therapy approaches in animal models of DMD.

Gene therapy is a very promising treatment for Duchenne. It works by introducing a smaller version of the dystrophin protein (micro or mini dystrophin), which is the protein lacking in individuals with Duchenne. Recent clinical trials have shown some individuals experience severe side effects due to an immune response to this microdystrophin being introduced through this therapy.

Dr. Odom’s team aims to find a way to circumvent this immune response by engineering utrophin variants to allow improved function and “immuno-silence” portions of the micro-protein. They hope to develop a safer, more productive version of a therapeutic protein to treat Duchenne muscular dystrophy.

Dr. Louis Kunkle

Dr. Louis Kunkel

Boston Children’s Hospital – Boston, MA
“A novel therapeutic approach for Duchenne Muscular Dystrophy centered on the NOTCH pathway modulation of Muscle Satellite Cells”

Dr. Kunkel is an internationally recognized geneticist with years of experience and scientific success in the understanding of the basis for muscular dystrophies. He received a B.A. from Gettysburg College and his Ph.D. from Johns Hopkins University. Over the past four decades Dr. Kunkel has devoted his career to understanding the molecular basis, and developing therapy, for neuromuscular disorders.

Dr. Kunkel is universally recognized for his 1986 identification of dystrophin as the causative gene in Duchenne muscular dystrophy.  His current work centers on developing dystrophin independent therapies for Duchenne muscular dystrophy to complement existing therapies currently in development.  He has received numerous awards for his research including membership to the National Academy of Sciences and The American Academy of Arts and Sciences.  Dr. Kunkel received the 2009 March of Dimes Prize in Developmental Biology for this pioneering work on muscular dystrophy. He leads a long-standing effort to develop novel therapies.

The decline of motor function due to muscle breakdown is a hallmark sign of Duchenne muscular dystrophy. The root cause is the lack of the protein dystrophin. Yet, what if you could improve a patient’s muscle regeneration independently of the amount of dystrophin protein?

Dr. Kunkle’s team has discovered a biochemical pathway called the Notch pathway. This pathway is a master regulator of muscle satellite cells directly responsible for muscle regeneration. Based on these findings, his lab intends to find a Duchenne therapy that could benefit all boys and young men with Duchenne regardless of their specific mutation.

Funded Projects in 2021

Picture of Dr. Niclas Bengtsson

Dr. Niclas Bengtsson

University Of Washington – Seattle, WA
“Development of gene regulatory cassettes that enable safe- and efficient in vivo dystrophin gene-editing in muscle stem cells.”

Dr. Niclas Bengtsson is an Assistant Professor in the Department of Neurology at the University of Washington School of Medicine. He received a M.Sc. degree in biomedical engineering at the Royal Institute of Technology in Stockholm, Sweden in 2003, and a Ph.D. in molecular cell biology at the University of Florida in 2009.

For the past 10+ years his research has been focused on developing novel and effective treatments for muscle diseases, in particular Duchenne muscular dystrophy (DMD). This research has included the use of MRI techniques to non-invasively evaluate dystrophic muscle pathology and treatment outcomes; studies of basic muscle stem cell biology and transplantation; and gene therapy & gene editing using viral vectors to deliver therapeutic genes in animal models of DMD.

Our research is focused on understanding key mechanisms responsible for pathologies observed in muscle disorders (particularly the muscular dystrophies), and on developing effective treatments to halt- or reverse muscle disease using gene therapy. As a part of the Wellstone Muscular Dystrophy Research Center at the University of Washington, we have designed promising methods that rely on CRISPR/Cas gene editing to correct genetic mutations and improve muscle health in Duchenne muscular dystrophy.

Through our ongoing collaboration with Dr. Stephen Hauschka, we have also developed effective approaches to limit gene therapy & gene editing to muscle tissue, thereby drastically reducing the risk of unintended treatment side effects.

Current research efforts include expanded use of several different technologies that improve or enable genomic correction in both muscle tissues and in muscle stem cells. This also includes investigations of new methods that enhance the overall safety of gene editing and offer expanded applicability to other genetic muscle degenerative conditions. Several innovative platforms are currently being evaluated that allow for early screening of novel approaches and facilitate validation in model systems prior to clinical translation.

Dr. Bengtsson’s project is designed to find ways to activate genes, specifically in muscle stem cells. During the first year of his study, his team has identified regions within genes that are active only in muscle stem cells and which could be assembled into regulatory cassettes (RCs) able to control therapeutic gene activation. Further quantitative testing will be done to identify the best cassettes before moving forward with experimentation in animals. All necessary animal models have been acquired and are currently being bred to generate the necessary number of animals to support the proposed studies.

Watch Dr. Bengtsson’s Research Update Video

Picture of Dr. Natasha Chang

Dr. Natasha Chang

McGill University – Montreal, QC
“Inducing stress granule formation in muscle stem cells to treat DMD.”

Dr. Natasha Chang is an Assistant Professor in the Department of Biochemistry at McGill University. She obtained her Ph.D. with Dr. Gordon Shore at McGill University studying BCL-2 family proteins and their role in regulating the cell survival autophagy pathway. Her studies highlighted a critical role for basal autophagy in the maintenance of skeletal muscle homeostasis.

Dr. Chang performed her postdoctoral training in the laboratory of Dr. Michael Rudnicki at the Sprott Centre for Stem Cell Research at the Ottawa Hospital Research Institute. During her postdoctoral fellowship, she made seminal contributions establishing the role of the dystrophin-glycoprotein complex in regulating muscle stem cell fate. Importantly, she demonstrated that dystrophin deficiency in muscle stem cells leads to altered epigenetic gene regulation in the mdx mouse model of Duchenne muscular dystrophy.

Dr. Chang’s research program at McGill investigates the molecular regulation of muscle stem cell biology in healthy and degenerative contexts with a focus on strategies to enhance stem cell function to treat muscle diseases.

The Chang laboratory at McGill University is focused on understanding the complex biology of muscle stem cells. Muscle stem cells play an important role in supporting the maintenance and health of skeletal muscle, a tissue that is capable of remarkable regeneration and repair. Our research also examines how muscle stem cell biology is impacted in the context of muscle diseases such as Duchenne muscular dystrophy (DMD).

DMD is a devastating degenerative disease that affects 1 in every 5,000 Canadian male births. Patients with DMD suffer from progressive muscle weakening and atrophy, which results in reduced mobility and ambulation, and eventual death from heart muscle and breathing complications. To date, there remains no effective cure for DMD. Our research program aims to harness the regenerative potential of muscle stem cells as a therapeutic avenue for treating DMD.

Importantly, emerging research studies have found that DMD stem cells do not function as healthy muscle stem cells, and their dysfunction plays a role in disease progression. Our research utilizes DMD models and patient cells to understand how stem cell function is altered in DMD muscle stem cells. Using this knowledge, we are also investigating novel strategies that target muscle stem cells in DMD to restore their ability to make muscle and enhance regeneration. Our research provides a proof-of-concept for stimulating muscle stem cells as a treatment strategy for patients with DMD.

Dr. Chang’s team has made considerable progress in their research project, “Inducing stress granule formation in muscle stem cells to treat DMD.” They have optimized several molecular and cell biology assays that will allow them to understand the mechanism of action of the small molecule inhibitors they employ to improve muscle differentiation. Moreover, validation of these inhibitors in mouse models of Duchenne muscular dystrophy is currently underway. Their funding from Defeat Duchenne Canada has provided their research team with invaluable opportunities to support postdoctoral fellows’ training and graduate and undergraduate students.

Watch Dr. Chang’s Research Update Video

Picture of Dr. Ronald Cohn

Dr. Ronald Cohn

The Hospital For Sick Children (SickKids) – Toronto, ON
“Simultaneous DMD gene editing and upregulation to restore protective levels of full-length dystrophin in the treatment of DMD duplication mutations.”

Dr. Ronald Cohn has served as President and CEO of the Hospital for Sick Children (SickKids) in Toronto, Canada, since May 1, 2019. Dr. Cohn joined SickKids in September 2012 as the Chief of the Division of Clinical and Metabolic Genetics, Co-Director of the Centre for Genetic Medicine, and Senior Scientist at the SickKids Research Institute. He became the Inaugural Women’s Auxiliary Chair in Clinical and Metabolic Genetics in April of 2013 and joined the Department of Molecular Genetics at the University of Toronto. In 2016, he was appointed Chief of Paediatrics at SickKids and Chair of Paediatrics at The University of Toronto.
Dr. Cohn received his medical degree from the University of Essen, Germany. After his postdoctoral fellowship at the Howard Hughes Medical Institute in the laboratory of Dr. Kevin Campbell, he moved to Baltimore, where he was the first combined resident in pediatrics and genetics at Johns Hopkins University. He subsequently joined the faculty of the McKusick-Nathans Institute of Genetic Medicine at Johns Hopkins, where he became the director of the world’s first multidisciplinary centre for Hypotonia, which has earned national and international recognition.
Dr. Cohn was also the director of the medical genetics residency program at Johns Hopkins. He has received numerous awards, including the David M. Kamsler Award for outstanding compassionate and expert care of pediatric patients in 2004, the First Annual Harvard-Partners Center for Genetics and Genomics Award in Medical in 2006, and the NIH Young Innovator Award in 2008.
Over the last few years, Dr. Cohn has developed an interest in applying the concept of Precision Child Health to the care of children. His own research focuses on implementing genome editing technologies for the treatment of neurogenetic disorders.

Duchenne muscular dystrophy (DMD) is a life-limiting neuromuscular disease with no cure and treatment being limited to symptom management and delay of disease progression. Dystrophin is a protein essential to muscle integrity. Without enough of it, muscles accumulate damage and weaken over time. Mutations in the gene encoding dystrophin prevent the expression of this protein in muscles, leading to the onset of DMD. Of all the types of DMD-causing mutation, duplications are the second most common.

With major advancements in CRISPR/Cas9 genome editing technology, the underlying genetic causes of DMD are now feasible to correct. We recently utilized CRISPR/Cas9 to remove a duplication mutation and recover dystrophin in DMD mice. While the mice greatly improved, dystrophin levels remained too low to completely prevent DMD.

We believe that increasing the amount of dystrophin protein is necessary to achieve complete disease protection. This project will therefore focus on a new strategy that combines our unique duplication removal approach with dystrophin upregulation into a single therapy. We aim to accomplish this by fusing Cas9 to activator proteins, enabling simultaneous correction of the DMD mutation and an increase in expression of the newly repaired dystrophin gene.

Presently, we have demonstrated this Cas9 fusion protein can still efficiently edit the duplication target for removal while also upregulating the dystrophin protein in mouse cells. Our next step is to evaluate this strategy in our DMD duplication mice and compare its effectiveness to our previous approach.

We anticipate this combined strategy will result in dystrophin reaching levels sufficient to prevent the progression of, and possibly reverse, DMD. If successful, this would be the first demonstration of such a combined approach in an animal. The therapeutic impact of dystrophin upregulation would also be shown, which may be applied to enhance other genome editing strategies and existing therapies for DMD. We firmly believe the results of this work would represent a meaningful step towards a cure for DMD as it effectively treats the underlying cause of the disorder.

Picture of Dr. Sachiko Sato

Dr. Sachiko Sato

Université Laval – Quebec City, QC
“Development of a Monosaccharide Therapy Using N-Acetylglucosamine to Mitigate Duchenne Muscular Dystrophy.”

Dr. Sato graduated from the Faculty of Pharmaceutical Science, Chiba University. After working as a research assistant in the toxicology department of Japan Hoffmann-la-Roche Research Center, she joined as a postgraduate student in the laboratory of Dr. Akira Kobata, the Institute of Medical Science, the University of Tokyo, Japan, in 1987. She also worked in the laboratory of Dr. R. Colin Hughes, MRC: National Institute for Medical Research in London, UK.

She obtained her Ph. D. from the University of Tokyo in 1994. As a postdoctoral fellow in the laboratory of Dr. Ron Kopito, Stanford University, she was involved in the work on cystic fibrosis. This work established the precedent that a genetic disease can be remediated by a chemical mean for the first time. This concept has been now elaborated as a “corrector” treatment for cystic fibrosis.

This paradigm shift concept using a small molecule for a genetic disease therapy remains engraved in her research mind. She became the principal investigator of the laboratory of glycobiology in Research Center for Infectious Diseases, assistant professor of the Faculty of Medicine, Laval University, Quebec, Canada, in 1999, and full professor since 2010. She is also the director of the Bioimaging platform since 2003. While her research interest has been the role of galectins in innate immunity, the focus of her laboratory recently has been shifted to the study of the therapeutic potential of galectins for the treatment of muscular dystrophies after her laboratory accidentally found the role of galectin-3 and N-acetylglucosamine, which increases the functions of galectin-3, in both myogenesis and muscle functions.

Our ultimate goal of the research program is to develop the use of orally administered N-acetylglucosamine (GlcNAc) as a therapy for ALL patients with Duchenne muscular dystrophy.

An eccentric contraction is the action of an active muscle lengthening under load, for example, when walking downhill. Repeated eccentric contractions are one cause of muscle injury. Muscle fibers are attached to the basal lamina through multiple protein-protein and protein-oligosaccharide interactions to protect against contractions.

The most critical attachment is through the interaction between laminin in the basal lamina and unique oligosaccharides attached to a-dystroglycan, a component of the dystrophin-glycoprotein complex (DGC), which links to the cytoskeleton of muscle fibers. This sugar-mediated interaction provides jelly-like adhesion of muscle fibers to the extracellular matrix and acts as a shock absorber against tension since the oligosaccharides are intrinsically hydrophilic and structurally flexible. Thus, from both intracellularly (dystrophin) and extracellularly (a-dystroglycan), DGC plays a unique shock cushioning role, providing mechanical stability to the muscle membrane to withstand the contraction forces.

Muscles of Duchenne muscular dystrophy (DMD) patients lack the expression of dystrophin, which leads to the reduced levels of DGC complex and a-dystroglycan on the sarcolemma. In other words, DMD muscles lack extracellular and intracellular shock absorbers to tolerate the forces of contraction and relaxation. Their myofibers are not properly fixed to the basal lamina and detach from it during contraction, leading to muscle damage. Fiber degeneration is counter-balanced by myogenesis at the expense of adult myogenic cells. The constant degeneration of muscle fibers eventually overwhelms the capacity of myogenesis. A lack of dystrophin also impairs myogenesis itself. To improve the quality of life, some possible approaches to delay DMD progression are strengthening muscle fiber attachments to the cell matrix to protect from eccentric contractions and increasing the efficiency of myogenesis.

Our previous results indicated that intraperitoneal treatment (administered through the abdominal cavity) with the monosaccharide GlcNAc for 10 days could counteract the progression of DMD in a mouse model of the disease. Further, our latest preliminary results suggest that 30-days oral treatment with GlcNAc reduced muscle damage. In vitro, GlcNAc (but not glucosamine) increased the efficiency of myogenesis. Notably, GlcNAc is found in human milk at high levels.

A 52-week toxicology study in rats (2.5 g/kg body weight/day, equivalent to 0.6 g/kg/day in humans) and a 4-week clinical trial (6 g/day) in patients with inflammatory bowel disease suggest that GlcNAc is safe. The specific aims of this proposed project are thus to obtain preclinical data to determine the effective oral doses and the efficacy of long-term treatment with GlcNAc for preventing the progressive degeneration of skeletal muscle and heart in mouse models of DMD, in preparation for phase I/II clinical trials.

Two-Year Fellowship Grant in Partnership with PPMD

Parent Project Muscular Dystrophy (PPMD), a US non-profit organization leading the fight to end Duchenne muscular dystrophy (Duchenne), and Defeat Duchenne Canada, Canada’s leading charity fighting to defeat Duchenne, announced a collaborative research award of $172,000 (CAD) in support of a two-year Clinical Fellowship in Duchenne Endocrinology and Bone Fragility. The award will sponsor the fellowship of Dr. Kim Phung under the guidance of Dr. Leanne Ward, Professor of Pediatrics and Research Chair in Pediatric Bone Health at the University of Ottawa.

Infrastructure Grant: Satellos Bioscience

Defeat Duchenne Canada provided a research partnership and infrastructure grant to support the development of Satellos’ novel approach to treating Duchenne.

Satellos scientists are developing small molecule drugs that they believe will restore faulty regeneration and repair observed in the muscles of patients with Duchenne and potentially other degenerative muscle disorders. The company’s drug candidates regulate the activity of an enzyme, codenamed PTP-X, which Satellos discovered is involved in controlling muscle stem cell function, allowing these stem cells to properly divide and repair damaged tissue that accumulates in the muscles of Duchenne patients.

Funded Projects in 2020

Picture of Dr. Eric Hoffman

Dr. Eric Hoffman

ReveraGen BioPharma – Rockville, MD
“Clinical Trial of Vamorolone in an Expanded Age Range of DMD Subjects.”

For the first time ever, Defeat Duchenne Canada has granted $1 million dollars to support a single project – the clinical trial of vamorolone in Canada. This anti-inflammatory therapy, currently under investigation, has shown promising benefits, with a better safety profile than traditional corticosteroids. Furthermore, the VBP15-006 trial is focused on collecting data in a broader age population, which remains a major gap in clinical trials today. 

Eric Hoffman is a human geneticist and translational researcher focused on neuromuscular disease, and skeletal muscle tissue in health and disease. Currently, he is Associate Dean for the School of Pharmacy and Pharmaceutical Sciences, Binghamton University – SUNY. In the private sector, he is co-founder and CEO of ReveraGen Biopharma, co-founder and Vice President of AGADA Biosciences, and co-founder and President of TRiNDS LLC; each company focuses on different aspects of orphan drug development. 

The standard of care for Duchenne muscular dystrophy remains high dose corticosteroids (prednisone or deflazacort), as they have been demonstrated to improve muscle strength and prolong ambulation. However, corticosteroids are well-known to have extensive side effects, and the doses given to DMD boys are higher and for longer periods of time than other patients who are typically prescribed corticosteroids. Thus, the side effects seen by DMD boys are often more severe than in typical cases. Side effects include stunting of growth, bone fragility and bone breaks, mood disturbances, delay of puberty, Cushingoid (moon face) features, hirsutism (extra growth of hair) and others.

Dystrophin replacement strategies hold promise in improving the muscle strength of DMD boys. However, all dystrophin replacement strategies are done in combination with corticosteroids. This is because all the dystrophin replacement strategies use highly modified, semi-functional dystrophin proteins, where inflammation of muscle still occurs, and corticosteroids help reduce this inflammation. Moreover, in gene therapy treatment, corticosteroid doses are often increased over what is normally prescribed to DMD boys in an effort to prevent inflammation caused by the viral vectors used in gene therapy.

What is needed is a safer steroid that still improves DMD patient strength and mobility, and still works with dystrophin replacement therapies, but without the wide range of side effects that prednisone and deflazacort show.

Vamorolone was developed to separate out the benefit from the safety concerns of traditional corticosteroids. Vamorolone is still a steroidal anti-inflammatory, but it is not a corticosteroid or glucocorticoid (e.g. not in the same class of drugs as prednisone or deflazacort). Tweaks of the chemistry of vamorolone led to differences in how it binds ‘receptors’ that mediate its effects on the body.

There are two receptors that both corticosteroids and vamorolone bind to the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR). When a drug activates the receptor, it is called an “agonist”; when it blocks and inactivates the receptor it is called an “antagonist”. Prednisone is an agonist for the mineralocorticoid receptor, and this adds to side effects. Vamorolone does the opposite to the MR – it is an antagonist, and in mice shows heart-healthy activities very similar to eplerenone (a cardiac drug often used in DMD). For the glucocorticoid receptor, prednisone and deflazacort are potent agonists as well, and this mediates both the anti-inflammatory effects (benefit) but also many of the side effects.

Vamorolone is a ‘partial agonist’ of the glucocorticoid receptor, where it retains the activities associated with benefit (anti-inflammatory activity) but loses much of the activity associated with side effects. In a word, the tweaks of the chemistry of vamorolone lead to tweaks in how the drug interacts with both GR and MR compared to prednisone and deflazacort.

To date, clinical trials of vamorolone have been carried out in DMD boys, where the boys were young when they entered the trials (4 to <7 years), and were ‘steroid naïve’ (never treated with corticosteroids like prednisone or deflazacort). The young age was important to determine if vamorolone preserved muscle function and the steroid-naïve was important to see if vamorolone developed side effects. 

If the patients were already treated with prednisone or deflazacort before starting vamorolone, it would be challenging to see if side effects were due to previous treatment with corticosteroids, or due to new treatment with vamorolone. These initial clinical trials have gone well, and are published. Vamorolone treatment led to improvements in strength and mobility over 6 months of treatment, and these improvements were preserved over 1.5 years of treatment.

Importantly, key side effects, such as stunting of growth, were not observed with vamorolone treatment; the boys grew normally. This data is supportive of vamorolone having the potential to replace corticosteroid treatment in DMD. Perhaps most importantly, families have been quite satisfied with vamorolone treatment. Of the initial 48 DMD boys treated, the large majority have asked to remain on vamorolone (and not transition to corticosteroids) for over 2.5 years. 

A placebo-controlled double-blind clinical trial of over 100 DMD boys, ages 4 to <7 years, steroid naïve, is underway with recruitment in 11 countries at 33 academic medical centers. The COVID-19 pandemic has created challenges for the vamorolone clinical trials, as it has for most all clinical trials, but the study seems to remain on track, and will likely complete the 6-month key endpoint in the fourth quarter of 2020.

In the meantime, the vamorolone study team, as well as many families of DMD, have asked some important questions: Can a DMD boy that is treated with corticosteroids (prednisone, or deflazacort) transition to vamorolone? What will treatment do for boys older than 7 years, or younger than 4 years (broader age range than 4 to <7 years)? The European drug regulatory agency, the EMA, asked the vamorolone team the same questions and wanted a clinical trial initiated to address these questions before considered drug approval for vamorolone throughout Europe for DMD.

The new VBP15-006 clinical trial has been designed to address these questions, and Defeat Duchenne Canada has partnered with ReveraGen BioPharma to enable the activation of the trial in Canadian academic medical centers. Similarly, DuchenneUK has partnered with ReveraGen to activate the trial at sites in the United Kingdom.

VBP15-006 plans to enroll 44 DMD participants, with a broad age range (2 to <4 years; and 7 to <18 years). In addition, older participants can be previously treated with corticosteroids (prednisone or deflazacort). The clinical trial is 3 months long, and then participants can enroll in the expanded access protocol that is already active in Canada for long-term treatment with vamorolone, if the family and their physician wish this.

The funding from Defeat Duchenne Canada is the largest award ever provided by the foundation (Can$1M), and is provided in stages based on ReveraGen achieving key milestones (completion of the trial). Also, the funding is provided under a new ‘return-on-investment’ model for Defeat Duchenne Canada, where the funding will be repaid to Jesse’s Journey based on later drug sales of vamorolone internationally. If vamorolone is successful, Defeat Duchenne Canada will receive over 400% return on its investment in vamorolone. This can then be used to fund the charity and further philanthropic efforts. Other non-profit foundations internationally have partnered with ReveraGen similarly for this and other clinical trials of vamorolone (shared risk, shared benefit model).

Picture of Dr. Dongsheng Duan

Dr. Dongsheng Duan

University of Missouri, Columbia – MO
“Super AAV for DMD Gene Therapy.”

Gene therapy for Duchenne is making great strides. The work undertaken by Duan and his team aims to address the delivery of these gene therapies so they are can be made affordable and available to many Duchenne patients. 

Dr. Dongsheng Duan is the Margaret Proctor Mulligan Professor in Medical at the University of Missouri and a fellow of the National Academy of Inventors. He has made many seminal contributions in the field of gene therapy, with a focus on the development of the adeno-associated virus vector and Duchenne muscular dystrophy gene therapy. Dr. Duan has previously received a grant from Jesse’s Journey and we are proud to award him a research grant for his project entitled: “Super AAV for DMD gene therapy in human muscle”.

The fundamental problem in Duchenne muscular dystrophy (DMD) is the dystrophin gene mutation. If we can replace the mutated dystrophin gene with a good one, it will address the genetic cause of the disease and treat DMD at the root. Research in gene replacement therapy has been a longstanding goal for Jesse’s Journey from the very beginning.

After more than three decades of research, investigators have identified adeno-associated virus (AAV) as an ideal vector to deliver a therapeutic gene to patients suffering from inherited diseases. AAV is the name for a family of viruses. There are hundreds of members in the family. They are named AAV1, 2, 3 etc. FDA has recently approved two gene therapy drugs that are made of AAV2 and AAV9.

The AAV2-based drug is currently being prescribed to children who suffer from a rare blindness disease and the AAV9-based drug is currently being prescribed to infants who suffer from an inherited motor neuron degenerative disease.

Two AAV family members are now being tested in Duchenne boys to deliver a miniaturized micro-dystrophin to the muscle throughout the body. These are AAV9 and AAVrh74. To treat all muscles in the body, investigators have to inject at least 1015 particles of one of these two AAV vectors to a single patient. While preliminary analyses have revealed promising results, the infusion of trillions of AAV particles has also resulted in life-threatening immune responses and severe adverse reactions (such as liver toxicity) in some patients.

If we can find a new AAV that is much more potent than AAV9 and AAVrh74, we will achieve the same therapeutic efficacy at a much lower dose. This should greatly reduce the risk of adverse reactions and immune responses. The purpose of this project is to identify such a super-potent AAV virus for gene delivery in the human muscle. Besides reducing toxicity, we believe this super-AAV will also greatly reduce the burden of AAV manufacture, and hence making the therapy affordable and available to many more Duchenne patients.

Picture of Dr. Jordan Sheriko

Dr. Jordan Sheriko

Dalhousie University – Halifax, NS
“A survey of Canadian youth with Duchenne and Becker Muscular Dystrophy exploring gender identity, sexuality, sexual health questions and.”

This is the first time Defeat Duchenne Canada is supporting work that is focused on Duchenne patient care related to sexual health. This is an area often forgotten about with very little data as it pertains to young people with Duchenne and Becker. Dr. Jordan Sheriko, Assistant Professor of Pediatrics and Medicine at Dalhousie University in Nova Scotia, and the Medical Director of Pediatric Rehabilitation at the IWK Health Centre, in collaboration with Dr. Carly Baxter aim to explore questions and concerns related to gender identity, sexuality and sexual health in individuals with Duchenne and Becker muscular dystrophy.

Dr. Sheriko and his team have created a survey to explore the issues related to sexual health and gender including whether individuals feel their needs are being met. The survey will be mailed out using the Canadian Neuromuscular Diseases Registry (CNDR). The information will help better understand this important topic and give guidance to neuromuscular clinicians on the concerns and experiences of the adolescent and young adult DMD population.

Dr. Sheriko and his team hope this work will form the basis of understanding sexual health and gender issues so that healthcare teams feel confident in asking youth sexual health questions and are able to counsel and provide appropriate information and resources.

Picture of Dr. Jacques P. Tremblay

Dr. Jacques P. Tremblay

Université Laval – Laval, QC
“Correction by CRISPR base editing of point mutations responsible for Duchenne Muscular Dystrophy.”

Dr. Tremblay’s laboratory aims to develop therapies to treat Duchenne individuals with point mutations affecting about 30% of Duchenne patients. His novel CRISPR approach is important as it addresses corrections to the dystrophin gene that cannot be treated by exon skipping therapies.

Dr. Jacques P. Tremblay, Professor in the Department of Molecular Medicine at Laval University in Quebec, has been award a research grant for his project entitled: “Correction by CRISPR base editing of point mutations responsible for Duchenne Muscular Dystrophy.”

The laboratory of Dr. Jacques P. Tremblay has been working on the development of a cell and gene therapy for Duchenne Muscular Dystrophy (DMD) since the discovery of the dystrophin gene in 1987. DMD is due to many different mutations in the dystrophin gene, all leading to the absence of dystrophin under the membrane of the muscle fibres. This leads to more frequent breaks of the muscle fibre membrane and to progressive muscle weakness.

Genes are in fact a sequence of pairs of nucleotides, which form the DNA, a double-strand helix. There are four different nucleotides (A:adenosine, T:thymidine, C:cytosine and G:guanine) forming four pairs A:T, T:A, G:C and C:G. Proteins, such as the dystrophin protein, are formed by 20 different amino acids. The genes (i.e., the DNA) code for the proteins. However, since there are only 4 different nucleotides it takes a sequence of three nucleotides (called a codon) to code for one amino acid. However, there are 3 different codons, which are stop codons. They indicate to the cell that the protein is finished.

Tremblay’s laboratory has been mainly working on the transplantation of myoblasts (the cells that form the muscle fibres) derived from a healthy donor as a treatment for all possible mutations in the dystrophin gene. Indeed, these myoblasts contain the normal dystrophin gene and thus introduce in the muscle fibres of the DMD patients the normal gene. This type of treatment is currently in Phase I/II clinical trial in collaboration with Dr. Craig Campbell (London Health Institute). Unfortunately, the main problem of this type of treatment is that because the myoblasts are derived from another person, the patient has to be immunosuppressed with Tacrolimus to prevent rejection. Such immunosuppression increases the risks of cancer and infections. Due to this problem, the human ethics committee has limited participation to patients who are more than 16 years old so that they can give fully informed consent. Health Canada has also imposed that DMD patients should not have a tracheotomy. These two restrictions are greatly impeding the progress of the clinical trial.

An alternative to avoid the requirement for sustained immunosuppression with Tacrolimus is to transplant to the patient his own myoblasts. However, these myoblasts would have to contain a normal dystrophin gene. The dystrophin gene itself is too big to be easily introduced in the patient myoblasts. Some researchers are working on introducing a smaller dystrophin gene, i.e., a micro-dystrophin gene containing the beginning and the end of the gene.

The dystrophin gene contains 79 parts (called exons). These exons are separated by nucleotide sequences (called introns), which do not code for a protein. Different exons are made of sequences of a different number of nucleotides. About 70% of the DMD patients have a deletion of one or several exons. Depending on which exons are deleted the total number of deleted nucleotides will vary. When the total number of deleted nucleotides, which are deleted in not a multiple of 3 nucleotides, the codons, which follow the deletion is changed, i.e., they will not code for the right amino acid. Eventually, one of the modified codons will be a stop codon and the dystrophin protein will be terminated. This dystrophin protein will have an adequate beginning but not an adequate end. This truncated protein will not be able to attach under the membrane of the muscle fibre. This absence of dystrophin leads to DMD. Some researchers are trying to restore the expression of an internally deleted dystrophin gene by deleting additional exons located just before or after the exons deleted in the patient dystrophin gene. This is called exon skipping. The aim of doing these additional deletions is that the total number of deleted nucleotides becomes a multiple of three. When this is the case the amino acids before the deletion and after the deletion are correct. The resulting internally deleted dystrophin protein will be able to attach under the muscle fibre membrane, but it will be more or less functional depending on the part of the dystrophin protein, which is missing. This is the case of the Becker patients.

An alternative is to correct the dystrophin gene present in the patient’s own myoblasts. About 30% of DMD patients have a point mutation (i.e., the change of only one nucleotide pair). Very often the mutation of one nucleotide pair results in the formation of a stop codon. Thus, the formation of the dystrophin protein ends prematurely, there is just the beginning of the dystrophin protein and not the end of that protein. Thus, the dystrophin protein is not present under the muscle fibre membrane and the patient is dystrophic just because there is one pair of nucleotides, which is mutated, the rest of the dystrophin gene is perfect! Our objective is to develop therapies for DMD due to such point mutations. A new base editing technique (called PRIME editing) derived from the CRISPR/Cas9 technology permits in principle to modify at will a targeted pair of nucleotides. There is only one article, which has been published about that technology a few months ago. The authors of that article have described the modifications of pairs of nucleotides in several genes but not in the dystrophin gene. The grant that we have obtained from Jesse Journey will permit to my team to test that PRIME editing technology on the dystrophin gene. We will initially test this technique to correct the point mutation present in the MDX mouse model of DMD. We also have a list of the point mutations observed in Canadian DMD patients. These are the point mutations that we will aim to correct. Eventually, this PRIME editing technique would permit to correct the point mutations directly in the myoblasts of the patients to permit the transplantation of the patient’s own myoblasts thus avoiding the use of the Tacrolimus immunosuppression. However, our ultimate goal would be to correct the point mutations directly in the dystrophin genes inside the muscle fibres of the patient. The PRIME editing technology may also be used to induce the skipping of exons for the 70% of patients who have a deletion of one or several exons. This would be done by just changing 1 nucleotide at the beginning of the exon(s) to be skipped.

The PRIME editing technique may eventually be used to correct point mutations responsible for hundreds of other hereditary diseases due to point mutations.

Picture of Dr. Lawrence Korngut

Dr. Lawrence Korngut

University Of Calgary – Calgary, AB 
“Canadian Neuromuscular Disease Registry”

Defeat Duchenne Canada was an original funder of the CNDR, and to date, has contributed more than $1 million towards the development and maintenance of the registry.

Dr. Lawrence Korngut is a neurologist, clinical neurophysiologist and Director of the Calgary Neuromuscular Program and the Calgary ALS and Motor Neuron Disease Clinic in Alberta. Dr. Korngut has been instrumental in the creation of the Canadian Neuromuscular Disease Registry (CNDR) along with Dr. Craig Campbell, Dr. Jean Mah, Dr. Bigger and other Canadian clinicians in establishing and growing the registry to what it is today.

The Canadian Neuromuscular Disease Registry (CNDR) is a Canada-wide registry of people diagnosed with a neuromuscular disease, like Duchenne or Becker muscular dystrophy. It safely and securely collects important medical information from patients across the country to facilitate research that benefits patients, families and caregivers. Those who participate can feel confident they are helping to promote the development of effective therapies for neuromuscular diseases.

Currently, over 4,600 neuromuscular patients have registered from across Canada and Defeat Duchenne Canada encourages you to join

Funded Projects in 2019

Picture of Dr. Toshifumi Yokota

Dr. Toshifumi Yokota

University Of Alberta – Edmonton, AB
“CRISPR/Cas9-mediated Gene Editing Therapy Targeting the N-Terminal Hotspot in the DMD Gene.”

Duchenne muscular dystrophy (DMD) is the most common neuromuscular disorder with a life-limiting disease trajectory. Majority of DMD causing mutations are large chromosomal deletions resulting in the absence of dystrophin protein. Despite significant advances in our understanding of the DMD pathogenesis, there is no cure. Recent advances in genome editing technologies have the potential to develop into curative therapies for DMD. Recently we have pioneered an approach to remove duplications within the DMD gene and developed several strategies to correct large chromosomal deletions creating a foundation for treating DMD patients. Due to the lack of available animal models carrying large DMD mutations, we generated two novel mouse models recapitulating large deletions in the dystrophin gene observed in patients. The overall goal of the current project is to develop clinically relevant genome editing strategies to correct DMD causing deletions in newly generated animal models resulting in expression of functional dystrophin.

Picture of Dr. Craig Campbell

Dr. Craig Campbell

London Health Sciences Center, London ON, and Dr. Jacques Tremblay, Laval University, Quebec City, QC
“Myoblast Transplantation to Treat Boys with Duchenne.”

Children’s Hospital – London Health Sciences Centre is a lead site for Myoblast transplantation in boys with Duchenne, a project funded by Jesse’s Journey in collaboration between Dr. Campbell and Dr. Tremblay. The project is currently under review, stay tuned for further details.

Photo of Dr. Michael Rudnicki

Dr. Michael Rudnicki

Ottawa Hospital Research Institute – Ottawa, ON
“Exosomal Delivery of Wnt7a for Treating Duchenne muscular dystrophy.”

Defeat Duchenne Canada in collaboration with Muscular Dystrophy Canada (MDC) are proud to fund Dr. Michael Rudnicki.

Duchenne muscular dystrophy is a devastating genetic disorder manifested by progressive muscle wasting and ultimately death around the second decade of life. Injection of a secreted protein called Wnt7a greatly enhances muscle regeneration resulting in amelioration of dystrophic progression. However, based on its chemical nature Wnt7a cannot be delivered via the blood circulation. We have discovered that Wnt7a is normally secreted on the surface of small vesicles called exosomes during muscle regeneration. Exosomes have been demonstrated to effectively deliver cargo through the circulation to muscle. We will compare the activity of free Wnt7a versus exosomal Wnt7a, we will investigate the mechanism that targets Wnt7a to exosomes, and we will test the ability of exosomal Wnt7a to be delivered to muscle through the circulation. These experiments have the potential to significantly increase the efficacy of Wnt7a for treating Duchenne muscular dystrophy, especially when used in combination with gene correction therapies.

We propose to investigate the cellular and molecular mechanisms through which exosomal Wnt7a acts and conduct preclinical studies to assess the therapeutic potential of systemic exosomal Wnt7a delivery through the circulation to ameliorate muscular dystrophy.

Objective 1. Determine the biological and specific activity of exosomal Wnt7a
We have determined that the majority of Wnt7a is secreted on the surface of exosomes in skeletal muscle following an acute injury. Very little to no Wnt7a appears to be secreted as free protein. In a head-to-head comparison, exosomal Wnt7a appears to exhibit a markedly superior specific activity to free Wnt7a.
Objective 2. Investigate the in vivo activity of exosomal Wnt7a
We have fully characterized muscle regeneration in mice carrying a floxed allele of Wnt7a. Notably, mdx mice lacking Wnt7a display a marked deficiency in muscle regeneration, thus serving as a sensitized readout to test systemic delivery of exosomal Wnt7a. We have also optimized the manufacture of exosomal Wnt7a by using trans-flow filtration (FF). We are now about to initiate these experiments.
Objective 3. Systemic delivery of exosomal Wnt7a
These experiments will be initiated shortly.

Picture of Dr. Anthony Gramonlini

Dr. Anthony Gramonlini

University of Toronto – Toronto, ON
“Non-viral immune modulatory nanoparticles for delivery of CRISPR/Cas9 as a treatment intervention for Duchenne Muscular Dystrophy.”

Defeat Duchenne Canada in collaboration with Muscular Dystrophy Canada (MDC) are proud to fund Dr. Anthony Gramonlini.

We are developing non-viral vehicles for the delivery of genome editing machinery with specific emphasis on targeting skeletal muscle cells associated with Duchenne muscular dystrophy (DMD). Clustered regularly interspaced palindromic repeats (CRISPR)-CRISPR associated protein 9 (Cas9) is a powerful new gene-editing tool. Our objective focuses on generating novel degradable and biocompatible nanoparticles (BNPs), using our U of T patented polyurethane technology. These carriers address limitations with current CRISPR/Cas9 delivery platforms, specifically eliminating the use of immune reactive virus; enables co-delivery of a specific targeting tool; and reduces potential off-target tissue damage; Studies will evaluate the therapeutic corrective capacity of nanoparticles in a DMD mouse model and establish a technology to enable novel therapies for DMD patients in Canada and abroad.

Dr. Gramonlini’s team is working toward their original goal of developing non-viral methods to deliver repair machinery to diseased skeletal muscle. They have shown success in a dish, completed the initial biochemical steps, and are now moving to the living mouse models of disease.

Burden of Illness Study

Muscular Dystrophy Canada (MDC), Toronto, ON

Defeat Duchenne Canada funded the study “Neuromuscular Disorders: Economic Impact and Health-Related Quality of Life” to help characterize the impact of neuromuscular disorders in Canada on affected children, adults and their caregivers, including direct costs, indirect costs, and impact on health-related quality of life.