We are aware that a drug-repurposing is not the best approach to halt the progression of Wolfram syndrome. We need cutting-edge treatments designed explicitly for Wolfram syndrome. Based on the clinical trial data of dantrolene sodium in patients with Wolfram syndrome, we have been actively developing novel drugs in collaboration with the drug development team at the National Institutes of Health (NIH)/National Center for Advancing Translational Sciences in the United States and a few biotech companies. We are currently focusing our efforts on developing AMX0035 together with Amylyx in Cambridge, MA, and ibudilast together with Professor Ehrlich at Yale University.
Washington University School Of Medicine
The study of liraglutide (Victoza) in Wolfram Syndrome that is being conducted by Drs. White and Marshall at Washington University has gotten off to a slow start because of the COVID-19 pandemic. However, they have now recruited 10 subjects who are in various stages of recruitment, screening or treatment. Two have already started treatment and eight more should be starting soon. If you are interested in participating, please contact Dr. White (white_n@wustl.edu or 314-286-1156) or Dr. Marshall (bmarshall@wustl.edu).
Catholic University of Leuven, Belgium
Genome editing for Wolfram syndrome:
Although rare individually, genetic disorders collectively constitute a common health problem. As the cause of these diseases is a defective gene, gene therapy would be able to resolve all of these disorders. Wolfram syndrome is a genetic disorder, with the ultimate symptoms of Diabetes, blindness and deafness in young kids. The most recent method of gene therapy is gene editing. Gene editing is repairing the defect of the gene by using molecular scissors such as CRISPR/Cas9. CRISPR/Cas9, which is the most commonly used type of this system is, composed of two components Cas9 protein which can make a cleavage in DNA and a guide RNA that is a RNA molecule which binds to Cas9 and guide it towards a specific target sequence of 20 bases. CRISPR/Cas9 allows us to cut the human genome by generating DNA double-strand breaks (DSB) close to the mutation. Such DSB is sensed by two main cellular repair pathways, nonhomologous end-joining (NHEJ) and homology-directed repair (HDR). While NHEJ is generally known to be an error-prone pathway causing insertions and deletions (indels) of DNA bases, which occurs independently of a repair template, HDR relies on the presence of a repair template to refill the correct bases and is considered an error-free pathway. Therefore, HDR has been extensively tested and used for precise gene editing. Given that HDR is restricted to the S and G2 phases of the cell cycle, only present in dividing cells, this approach might not be suitable for editing and repairing the genome in non-dividing cells. However many of monogenic disorders, including Wolfram syndrome cause disease, because the function of terminally differentiated non-dividing cells in different organs is impaired. Therefore, to reverse the defect caused by monogenic diseases, therapies that can correct the genetic defect in non-dividing cells are required. One very recent tool that is made based on CRISPR/Cas9 system is called Base editor. Base editing is a direct replacement of a single DNA base with the correct one without making a DSB and therefore not relying on HDR. Base editor (BE) is an engineered fusion enzyme consist of Cas9 and cytidine deaminase (CD) that enables a C-G to T-A conversion in an activity window that can be as narrow as 1-2 bases. Since the initial description, BE has been extensively improved and expanded. Another important base editing tool is adenine base editors (ABEs) contains a DNA adenosine deaminase instead of CD and enables a T-A to C-G transition. ABE is a major milestone in base editing considering that the target mutations (C-G to T-A ) account for half of the pathogenic known point mutations in human. Some of the mutations causing wolfram syndrome are targetable by ABE (e.g. c.2002 C>T or c.1620 G>A). ABE has been proven effective in mice on different non-dividing cell types including the cells in retina. However, due to differences between mice and human in many aspects and specifically on DNA repair system, before moving forward to clinical application of ABE, it is important to evaluate this tool on human cells in vitro (in a dish). Therefore, in our study we are planning to evaluate the efficiency of ABE on human derived non-dividing cells. Since these cells are not accessible from human, we will generate them in the lab from Wolfram patient derived stem cells. We are focused on two cell types; oligodendrocytes and retinal ganglion cells as two non-dividing cells leading to eye and brain related symptoms of Wolfram syndrome. We successfully differentiated our patient derived stem cells to oligodendrocytes and retinal ganglion cells. Next, we tested the efficiency of the ABE tool on the stem cells of patients to confirm that the tool is generated correctly. Our result showed highly efficient correction of the mutated DNA base in the stem cells of patients (around 90%). Therefore, we proceed with making delivery vectors to be able to get the ABE tool to oligodendrocyte and retinal ganglion cells. Our vectors are successfully generated, and we are currently performing delivery of the tools to our target cells. We hope to release the result of this part in near future.
–Catherine Verfaille
Update January 26, 2024:
Dear Friends,
Thank you sincerely for your invaluable support of our collaborative study alongside Prilenia Therapeutics. As you are aware, our mission to find a cure for Wolfram syndrome involves three crucial steps:
Step 1: Slowing down the progression of the disease through the use of oral medications.
Step 2: Halting the progression via gene-editing therapy.
Step 3: Reviving damaged tissues with regenerative therapy.
Our current focus is on Step 1, specifically a clinical trial of AMX0035 in adult patients with Wolfram syndrome. This trial is designed to target endoplasmic reticulum stress (ER stress), a key mechanism underlying the syndrome. In many diseases, such as cancer, we have successfully employed combination therapies, utilizing multiple drugs that target various molecular pathways affected by the condition. We aspire to adopt a similar strategy for Wolfram syndrome in our efforts to slow its progression. To achieve this, we are exploring the potential of additional oral medications that target different pathways.
One promising candidate is the Sigma 1 receptor, and we have initiated a collaboration with Prilenia, a biotech company specializing in this field. Together, we are investigating the effects of a drug called pridopidine, which targets the Sigma 1 receptor, in cellular models of Wolfram syndrome. We are grateful to the Snow Foundation in collaboration with Ellie White Foundation for their generous donations, which enables us to conduct this crucial study using cells derived from Wolfram syndrome patients. The study is currently in progress as we explore various experimental conditions to assess the efficacy of pridopidine. We are committed to providing you with regular updates on our progress.
Once again, we extend our heartfelt thanks for your generous support, which is instrumental in advancing our mission to find a cure for Wolfram syndrome and bring hope to those affected by this condition.
With grace and gratitude,
Fumi
Washington University School of Medicine
Our lab has been 100% functional and welcomed four new research team members in the past three months. So, we are ready to accelerate our progress. I continue adhering to my three guiding principles:
- Improve clinical care,
- Raise awareness, and
- Provide a cutting-edge treatment for Wolfram syndrome.
An Upcoming Trial
We just published the data of our drug-repurposing trial using dantrolene sodium in the Journal of Clinical Investigation Insight (https://insight.jci.org/articles/view/145188). This is an open-access article, and anyone can read it at no cost. Although the results were not what we had hoped, I learned a lot from this trial, which will help us design a new trial. As I repeatedly mentioned in the past, a repurposed drug could be just a band-aid for Wolfram. So, we need a new medication designed explicitly for Wolfram syndrome.
As you know, we have been focusing our efforts on developing AMX0035 for the treatment of Wolfram syndrome with Amylyx in Cambridge, Massachusetts, in the US. AMX0035 targets endoplasmic reticulum stress (a molecular mechanism of Wolfram) and mitochondria dysfunction. A recent clinical trial of AMX0035 in patients with ALS, an adult-onset neurodegenerative disorder, was successful (https://www.nytimes.com/2020/10/16/health/ALS-treatment.html). Our pre-clinical data using induced pluripotent stem cells (iPSCs)-derived brain cells of Wolfram syndrome and Wolfram mice were positive, and we plan to publish the data soon. US FDA granted an orphan drug designation of AMX0035 for the treatment of Wolfram syndrome in October 2020. We submitted our clinical trial plan to the US FDA late May, 2021, and received their feedback late July, 2021. We are revising our trial protocol to ensure the safety of our patients and assess the efficacy of AMX0035 accurately. I spend certain amount of time every single day on this together with medical officers at Amylyx and my colleagues at Washington University. We are making steady progress to start this trial.
Our clinical trial of AMX0035 in patients with Wolfram syndrome has been designed based on Dr. Barrett’s clinical trial design in Europe, Dr. Hershey’s research clinic data in St. Louis, and our dantrolene trial design and data in St. Louis. I have been closely working with Dr. Patrick Yeramian, Dr. Jüergen Reess and Dr. Jamie Timmons at Amylyx and Dr. Tamara Hershey at Washington University. Dr. Bess Marshall at Washington University kindly shared unpublished data with us, and Mrs. Hongjie Gu performed extensive statistical analyses to calculate the number of patients and duration of the study needed for the trial. Dr. Kent Leslie and Dr. Machelle Manuel at Amylyx have been working with patients to create a patient advisory board for the trial. Ms. Allison Lusis has been assigned to this important project as a lead for the regulatory affairs. My nurse coordinator, Mrs. Stacy Hurst, RN, and lab manager, Mrs. Cris Brown, are ready to conduct this at our medical center. I have been discussing the fundraising strategy for the trial with Mr. Josh Cohen and Mr. Justin Klee, co-CEOs of Amylyx. I have also identified potential grant support from the National Institutes of Health (NIH) and discussed this with a few NIH officers. I will keep on doing my best to start this trial as soon as possible.
Regenerative Gene Therapy
I am aware that we need a strategy to regenerate damaged tissues in patients with Wolfram syndrome, and my tool to accomplish this goal is to develop regenerative gene therapy. We have been trying to improve visual acuity and brain functions using viral vectors of a healthy Wolfram gene (WFS1) and a regenerative factor called MANF in rodent models of Wolfram and Wolfram iPSC-derived neurons and retinal ganglion cells. Our new preliminary results are encouraging. My goal is to start a trial in the next 3-7 years. It all depends on the fund and results of our pre-clinical studies.
Base Editing Gene Therapy
The best way to treat genetic disorders is gene-editing or base-editing-based therapy for sure. We have been working with Dr. David Liu’s team (Dr. Gregory Newby) at Harvard University/Broad Institute and Dr. Catherine Verfaillie and Dr. Lieve Moons’ teams at the Katholieke Universiteit Leuven to develop a novel gene therapy using base editing. This technology uses some components from CRISPR systems together with other enzymes to directly replace the abnormal WFS1 gene with the normal WFS1 gene. We have been getting positive results using iPSCs from Wolfram patients. I hope that we can bring this technology to our patients in the next 3-7 years.
Wolfram Genetics Clinic
To improve the clinical care for patients with Wolfram syndrome and Wolfram-related disorders, I created a new genetics clinic at the Center for Advanced Medicine, Washington University Medical Center, in 2020. We offer genetic evaluations, education, and counseling for patients and family members of all ages with or suspected to have Wolfram syndrome or WFS1-related disorders. We also provide personalized management plans based on the type of your gene variants together with other specialists at our medical center, such as Dr. Marshall. Wolfram syndrome Research Alliance, the Snow Foundation, and the Ellie White Foundation have been referring patients to us (https://wolframsyndrome.wustl.edu/). We accept international patients via our international patient care office. Please call +1-314-273-3780 to make an appointment. US patients can call +1-314-747-7300 to make an appointment.
I have been doing my best to save our patients. I welcome any feedback or questions (urano@wustl.edu). We will work as one team and make a difference together. Thank you for your faith in my work.
Sincerely,
Fumi Urano, MD, PhD
Fumihiko Urano, MD, PhD, FACMG
Professor of Medicine and of Pathology & Immunology
Samuel E. Schechter Endowed Professor in Medicine
Director, Wolfram Syndrome/WFS1-related disorders Registry & Clinical Study and WFS1 clinic at BJC HealthCare
Washington University School of Medicine
https://wolframsyndrome.wustl.edu/
Update March 5, 2024
Our focus is to discover preclinical Liraglutide and the rest of the GLP1 receptor agonists available on the market to help stop the progression of Wolfram syndrome. Moreover, we are looking into a new generation of GLP1 and GIP co-agonists for the same reason. We are also developing gene therapy against WS-associated neurodegeneration.
University of Tartu, Laboratory Animal Centre
Lifelong treatment with GLP1 receptor agonist in rat model of Wolfram syndrome
Treatment with GLP1 receptor agonists has been shown to normalize ER stress response in several in vitro and in vivo models. Recent research has shown beneficial effect of GLP1 receptor agonist treatment in rat and mouse models of Wolfram syndrome (WS). Early treatment with liraglutide was effective to prevent the development of diabetic phenotype in a rat model of WS. Furthermore, our recent results indicate that 6-month liraglutide treatment reduced neuroinflammation, cellular stress and excitotoxicity in the brainstem of the aged WS rats. Liraglutide treatment also protected retinal ganglion cells from cell death and optic nerve axons from degeneration.
As a WS is a lifelong condition and therefore, any pharmacological treatment of WS patients will also be lifelong. However, the long-lasting nor lifelong effect of such treatment has never been evaluated. Thus, we performed the lifelong experiment to evaluate the safety and efficacy of long-lasting treatment with GLP1 receptor agonist liraglutide in WS rats.
The WS rats were 2 months old at the beginning of the experiment and they were treated for 15 months with liraglutide. The progression of diabetic phenotype, loss of vision, loss of hearing and changes in the brain anatomy were monitored and evaluated during the experiment. Preliminary results are showing that liraglutide treatment delayed the progression of diabetic phenotype, brainstem degeneration, loss of vision and the progression of cataract of WS rat. Now our work is focusing on analyzing all collected data and tissues to make final conclusions of this lifelong liraglutide treatment.
This research was supported by Eye Hope Foundation, grant PUT PSG471 from the Estonian Research Council and by Novo Nordisk who supported us with Liraglutide.
With best regards,
Mario Plaas
University of Cambridge, United Kingdom
We are currently focusing our efforts on the following research areas.
- Disease progression and biomarkers
We are collecting a comprehensive range of ophthalmological data on individuals who have been confirmed to carry pathogenic WFS1 mutations, including high-resolution optical tomography tomography imaging and visual electrophysiology. We want to carefully document the changes happening in the retina and in the optic nerve, and how these relate to the worsening of vision. Our aim is to find out which are the best tests to detect whether the disease is progressing and eventually, the same tests can be used in future clinical trials to determine whether a new treatment is effective (or not).
- Zebrafish model of Wolfram syndrome
After spending much effort in the lab, we have developed a zebrafish model of Wolfram syndrome that replicates the RGC loss and visual dysfunction seen in individuals with this genetic condition. The availability of a zebrafish model for Wolfram syndrome provides a powerful tool to better understand the disease mechanisms that result in RGC loss and to screen for drugs that could potentially block this from happening in an effort to preserve vision.
Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia
Professor Kaasik and his colleagues from the University of Tartu (Estonia) are currently searching for small molecular compounds to improve the function of endoplasmic reticulum that could have potential for the treatment of Wolfram Syndrome. They have identified several compounds with the ability to improve endoplasmic calcium homeostasis and neuronal health in WS cellular models.
Best regards,
Allen Kaasik
Washington University School of Medicine
Drs Hershey, Marshall and the rest of the Wolfram Research Clinic team have been busy analyzing data that has already been collected and trying to plan for the next round of data collection during the current pandemic. We hope to start remote data collection (surveys, zoom interviews) this month, with in person ‘mini-clinics’ once the pandemic-related restrictions on travel and research are over. Samantha Ranck is coordinating this effort. Our primary goal is that everyone stays safe!
Some of the analyses we have done have been published in the past year and address the smell and taste differences, sleep problems and brain structure alterations in people with Wolfram syndrome. We hope that this information is helpful for families and physicians in understanding, monitoring and treating some of these symptoms.
Tamara Hershey, PhD
ULB Center for Diabetes Research, Brussels, Belgium
GLP-1 analogs, such as liraglutide, exenatide and dulaglutide among others, are used to treat type 2 diabetes. These drugs are known to promote pancreatic beta cell function and survival, may cross the blood brain barrier, and might have potential beneficial effect on neurons and retinal cells. GLP-1 analogs may therefore be of interest in Wolfram syndrome, to prevent or treat diabetes and potentially neurodegeneration.
In our Center we are studying whether different GLP-1 analogs are beneficial for pancreatic beta cells and neurons in Wolfram syndrome. To answer this question, we are using several preclinical models of Wolfram syndrome including WFS1- knockout mice, WFS1-deficient human beta cells, and induced pluripotent stem cells (iPSC) from people with Wolfram syndrome differentiated into beta cells and cerebellar neurons.
Our preclinical data indicate that GLP-1 analogs prevent and reverse diabetes in Wolfram syndrome mice, and improve the function and survival of WFS1-deficient human beta cells and iPSC-derived beta cells from patients with Wolfram syndrome. The effect of GLP-1 analogs on iPSC-derived neurons is currently under study but our preliminary results suggest that these drugs may help to prevent neuronal demise in Wolfram syndrome. Based on the preliminary data, liraglutide was started (off-label use) in two 9-year-old children with diabetes and Wolfram syndrome. Liraglutide lowered their sugar levels, reduced their glycemic variability, and reduced the amount of insulin needed by 40 to 75%. This improved glycemic control contributed to ameliorate the children’s quality of life and allowed them to switch to carbohydrate-richer diets.
Mariana Igoillo-Esteve, PhD
Miriam Cnop, MD PhD
In my lab, we are developing concomitantly two therapeutic strategies: a pharmacological approach and a gene therapy. To achieve these goals, we are working with suited animal models: two transgenic mouse lines and one zebrafish line. One mouse model and the zebrafish line are deficient for Wolframin, the protein responsible for Wolfram syndrome type 1. The other mouse model has been genetically engineered to mimic a human mutation, recapitulating sensorial deficits (vision and hearing loss) and diabetes. We are hoping to treat vision and hearing, as well as central neurodegeneration.
Update March 5, 2034:
We have explored the impact of the absence of Wolframin or the presence of an abnormal protein in the neurons of our mouse models (neurons of the hippocampus and cortex) as well as in patients’ fibroblast (cells cultured from the skin). Our findings suggest considering the use of the same therapeutic targets in both cases, thus opening treatment perspectives for patients carrying a mutation leading to an abnormal protein (Wolfram-like syndrome).
Using our zebrafish model of the disease, we have validated our gene therapy strategy. Based on these encouraging results, we are now investigating the outcomes of this approach in our mouse models.
Our gene therapy approach corrected the memory deficit and locomotor coordination alteration at least one month after the injection of the virus. In addition, the virus is efficiently transducing the affected brain structure such as cerebellum, hippocampus, or cortex and lasting in time.
We are now exploring vision and hearing loss of our preclinical models, following the injection of the virus.
University of Montpellier
My projects are focused on elucidating Wolfram syndrome molecular mechanisms and more particularly to study the role of the alterations of communication between two intracellular organelles named the endoplasmic reticulum (ER) and mitochondria, one of the key pathways in the disease. Based on this impairment, we are developing two therapeutical strategies to stop the progression of Wolfram syndrome. Associated with a prompt diagnosis, we are optimistic that the manifestations of the disease can be halted in a timely-manner, decreasing the probability to develop neurological and sensorineural symptoms.
Our first strategy is a pharmacological approach. We identified a strong and potent target expressed at the ER-mitochondria junction that interacts with Wolframin, the protein responsible for WS. Its activation restored the cellular alterations in patients’ fibroblasts and the altered behaviors observed in mouse and zebrafish models. Using a phenotypic screening in zebrafish, we already identified novel chemical entities that bind to our relevant target. Following these encouraging results, we are optimizing the molecules that will be tested in cells and in our different animal models. A multi-system screening method (zebrafish and mouse models) approach will be used to screen the panel of molecules and highlight compound that can eventually be used to treat WS patients.
We are also developing an innovative gene therapy. Based on recent studies in the lab, we have envisioned a different approach from what is currently developed. We decided to express a partner protein of Wolframin but not Wolframin itself. The size of this protein allowed us to use viral transfection using a virus already proven efficient in other disorders. By developing a unique gene therapy, which will be delivered systemically, we are hoping to stop the progression of the disease, body-wise, contrarily to the currently explored strategies. Our preliminary data in both zebrafish and mouse models of the disease are very encouraging. We are currently testing the long lasting effects of the gene therapy as well as its impacts on the different symptoms of the syndrome.
Best regards,
Benjamin
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