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A New Delivery System Offers Hope For Cystic Fibrosis
From its first description in 1935 until now, clinical outcomes for patients with cystic fibrosis have undergone a dramatic transformation. While the rare genetic disease was once an early death sentence that often prevented patients from reaching adulthood, advancements in cystic fibrosis therapeutics have greatly extended the lifespans of those suffering from the disease over the years.1 However, these therapies are not effective in all patients.
In a study published in Nature Communications, scientists reported a novel strategy to deliver the CRISPR-Cas9 gene-editing system into the lungs of a cystic fibrosis mouse model and correct the underlying mutations.2 Once developed and tested, this approach could allow clinicians to treat every patient with cystic fibrosis, including those who were previously untreatable.
Cystic fibrosis results from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which encodes a chloride channel on the cell surface that helps control the concentration of salt and water within bodily secretions. Impaired or absent CFTR activity leads to the characteristic thick and sticky mucus associated with the disease and consequently, an increase in the frequency of respiratory infections. Clinicians have developed small molecule drugs, such as Trikafta, that effectively treat 90 percent of patients.3
Yehui Sun and her colleagues developed a lipid nanoparticle-based delivery strategy to carry the CRISPR system from the bloodstream to the lungs to mediate CFTR gene correction in cystic fibrosis models.
James Raynard Dizon, UT Southwestern
"The problem is that these drugs are only for symptom management," said Yehui Sun, a graduate student in Daniel Siegwart's laboratory at the University of Texas Southwestern Medical Center and author of this study. "[These drugs cannot] cure the root of the disease because it is a genetic disease." The patient's cells must produce the CFTR protein for the existing therapies to work, which leaves patients with nonsense mutations without options.
Since its initial discovery, researchers believed that they could use CRISPR-Cas9 to help cure genetic diseases. However, the lack of effective delivery carriers that could target specific organs held back this approach. To solve this problem, Siegwart and his team previously developed an advanced delivery strategy called selective organ targeting lipid nanoparticles (SORT LNP).4 By modifying the composition and biophysical properties of these nanoparticles, the researchers selectively targeted cells in the lungs, livers, or brains of mice after intravenous administration.
Building on this work, Sun, Siegwart, and their team further optimized the formulation of their lung SORT LNP and improved its delivery, efficacy, and lung-targeting specificity, while producing minimum toxicity. After encapsulating the CRISPR system components including Cas9 mRNA, mutation-specific single guide RNA, and donor single stranded DNA template, they injected the lipid nanoparticles intravenously into a cystic fibrosis mouse model harboring the nonsense mutation, G542X. Through next-generation sequencing (NGS) of DNA extracted from its lung tissue, the researchers determined that their gene editing strategy successfully corrected the G542X mutation in murine lungs.
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While these results were promising, the researchers were unsure if their system could directly reach basal cells, which are resident stem cells in the respiratory epithelium. Because these cells can differentiate into various epithelial cell types, effective CFTR repair in basal cells could potentially lead to long-term improvements in lung function. By treating a transgenic reporter mouse strain with lung SORT LNP carrying Cre mRNA and evaluating the fluorescence of isolated basal cells using flow cytometry, they observed that their lipid nanoparticles could efficiently deliver mRNA to basal cells in vivo.
Efficient delivery of these [genome] editors to target the areas that we want it to work has always been an issue. -Amy Wong, The Hospital for Sick Children
To test if their approach could also improve CFTR function, Sun and her colleagues grew patient-derived human bronchial epithelial cells expressing the most common mutation in CFTR, F508del, onto a permeable membrane and treated the monolayer with lung SORT LNP. They then evaluated changes in the secretion of chloride ions by applying an electrical current across the epithelial layer and measuring the transepithelial resistance and voltage, as well as the gene editing efficiency through NGS. Although they found that their system repaired the mutation in only four percent of the cells, this correction rate was sufficient to restore the chloride channel's activity to 71 percent of healthy CFTR function.
"Efficient delivery of these [genome] editors to target the areas that we want it to work has always been an issue," said Amy Wong, a developmental and stem cell biologist at The Hospital for Sick Children, who was not involved in the study. "Lipid nanoparticles really address the question of delivery." Wong was particularly excited that the lung SORT LNP reached the basal cells in the lung epithelium. "If you target these stem cells, then you will have a source of cells that can just renew the epithelium and will have the correct CFTR on the plasma membrane," Wong explained.
Besides treating additional lung diseases, this SORT LNP delivery strategy holds much potential to provide targeted gene editing to cells in other areas of the body. "Cystic fibrosis is not a disease that only affects airways; it affects multiple tissues," Wong said. "Their intravenous delivery method…could potentially be an avenue to target other organs as well, such as the pancreas [or] the liver."
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Ferreting Out the Causes of Cystic Fibrosis
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ReferencesVertex Announces European Commission Approval For KALYDECO® To Treat Infants With Cystic Fibrosis Ages 1 Month And Older
- KALYDECO ® is the first and only medicine approved in the EU in this age group to treat the underlying cause of cystic fibrosis for specific mutations in the CFTR gene -
LONDON, April 26, 2024--(BUSINESS WIRE)--Vertex Pharmaceuticals (Nasdaq: VRTX) today announced that the European Commission has granted approval for the label expansion of KALYDECO® (ivacaftor) for the treatment of infants down to 1 month of age with cystic fibrosis (CF) who have one of the following mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene: R117H, G551D, G1244E, G1349D, G178R, G551S, S1251N, S1255P, S549N or S549R.
"Today's approval is an important milestone for the cystic fibrosis community. Treating CF early in life can potentially slow the progression of the disease, which is why it is so important to start treatment from a very young age," said Carmen Bozic, M.D., Executive Vice President, Global Medicines Development and Medical Affairs, and Chief Medical Officer, Vertex.
As a result of existing access agreements in Austria, Czech Republic, Denmark, Ireland, Norway, Sweden, and The Netherlands, eligible patients will have access to the expanded indication of KALYDECO® (ivacaftor) shortly following regulatory approval by the European Commission. Vertex will continue to work with reimbursement authorities across the European Union to ensure access for all other eligible patients. In the U.K., following MHRA approval at the end of 2023, and as a result of the existing reimbursement agreement between Vertex and the National Health Service, eligible infants ages 1 month and older in the U.K. Have access to this expanded indication for KALYDECO® (ivacaftor).
About Cystic Fibrosis
Cystic fibrosis (CF) is a rare, life-shortening genetic disease affecting more than 92,000 people globally. CF is a progressive, multi-organ disease that affects the lungs, liver, pancreas, GI tract, sinuses, sweat glands and reproductive tract. CF is caused by a defective and/or missing CFTR protein resulting from certain mutations in the CFTR gene. Children must inherit two defective CFTR genes — one from each parent — to have CF, and these mutations can be identified by a genetic test. While there are many different types of CFTR mutations that can cause the disease, the vast majority of people with CF have at least one F508del mutation. CFTR mutations lead to CF by causing CFTR protein to be defective or by leading to a shortage or absence of CFTR protein at the cell surface. The defective function and/or absence of CFTR protein results in poor flow of salt and water into and out of the cells in a number of organs. In the lungs, this leads to the buildup of abnormally thick, sticky mucus, chronic lung infections and progressive lung damage that eventually leads to death for many patients. The median age of death is in the 30s, but with treatment, projected survival is improving.
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About KALYDECO® (ivacaftor)
In people with certain types of mutations in the CFTR gene, the CFTR protein at the cell surface does not function properly. Known as a CFTR potentiator, ivacaftor is an oral medicine designed to facilitate the ability of CFTR proteins to transport salt and water across the cell membrane, which helps hydrate and clear mucus from the airways. KALYDECO® (ivacaftor) was the first medicine to treat the underlying cause of cystic fibrosis in people with specific mutations in the CFTR gene.
KALYDECO® (ivacaftor) is a prescription medicine for the treatment of people with CF aged at least 1 month and weighing at least 3 kg who have one of the following mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene: R117H, G551D, G1244E, G1349D, G178R, G551S, S1251N, S1255P, S549N or S549R.
For complete product information, please see the Summary of Product Characteristics that can be found on www.Ema.Europa.Eu.
About Vertex
Vertex is a global biotechnology company that invests in scientific innovation to create transformative medicines for people with serious diseases. The company has approved medicines that treat the underlying causes of multiple chronic, life-shortening genetic diseases — cystic fibrosis, sickle cell disease and transfusion-dependent beta thalassemia — and continues to advance clinical and research programs in these diseases. Vertex also has a robust clinical pipeline of investigational therapies across a range of modalities in other serious diseases where it has deep insight into causal human biology, including acute and neuropathic pain, APOL1-mediated kidney disease, autosomal dominant polycystic kidney disease, type 1 diabetes, myotonic dystrophy type 1 and alpha-1 antitrypsin deficiency.
Vertex was founded in 1989 and has its global headquarters in Boston, with international headquarters in London. Additionally, the company has research and development sites and commercial offices in North America, Europe, Australia, Latin America and the Middle East. Vertex is consistently recognized as one of the industry's top places to work, including 14 consecutive years on Science magazine's Top Employers list and one of Fortune's 100 Best Companies to Work For. For company updates and to learn more about Vertex's history of innovation, visit www.Vrtx.Com or follow us on LinkedIn, YouTube and Twitter/X.
Special Note Regarding Forward-Looking Statements
This press release contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995, including, without limitation, statements made by Carmen Bozic, M.D., in this press release, statements regarding the eligible patient population for KALYDECO, expectations for access to KALYDECO for eligible patients, including Vertex's plans to continue to work with reimbursement authorities across the European Union to ensure access for eligible patients, and statements regarding the potential benefits of KALYDECO. While Vertex believes the forward-looking statements contained in this press release are accurate, these forward-looking statements represent the company's beliefs only as of the date of this press release and there are a number of factors that could cause actual events or results to differ materially from those indicated by such forward-looking statements. Those risks and uncertainties include risks listed under the heading "Risk Factors" in Vertex's annual report and in subsequent filings filed with the Securities and Exchange Commission and available through the company's website at www.Vrtx.Com and www.Sec.Gov. You should not place undue reliance on these statements. Vertex disclaims any obligation to update the information contained in this press release as new information becomes available.
(VRTX-GEN)
View source version on businesswire.Com: https://www.Businesswire.Com/news/home/20240417151132/en/
Contacts
Vertex Pharmaceuticals Incorporated
Investors:InvestorInfo@vrtx.Com
Media:mediainfo@vrtx.ComorInternational: +44 20 3204 5275
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Electricity Could Make Cells More Receptive To Certain Gene Therapies
In an effort to improve delivery of costly medical treatments, a team of researchers in electrical engineering at the University of Wisconsin–Madison has developed a stimulating method that could make the human body more receptive to certain gene therapies.
The researchers exposed liver cells to short electric pulses — and those gentle zaps caused the liver cells to take in more than 40 times the amount of gene therapy material compared to cells that were not exposed to pulsed electric fields. The method could help reduce the dosage needed for these treatments, making them much safer and more affordable. The research appears April 30 in the journal PLOS ONE.
Gene therapy is a promising medical technology: By replacing, altering or introducing new genetic material into a patient's cells, doctors may be able to cure or compensate for genetic diseases, including cystic fibrosis, sickle-cell disease, hemophilia and diabetes.
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Subscribe for FREEOne of the bottlenecks in gene therapy, however, is getting the right dose of genetic material into the target cells. The UW–Madison research suggests that applying a moderate electric field, which left no lasting damage to the cells that received it, could help in creating more effective therapies.
The project began almost a decade ago with Hans Sollinger, a world-renowned transplant surgeon at UW–Madison. He had developed a gene therapy treatment for Type 1 diabetes, an autoimmune disease that attacks the pancreas, the organ that produces insulin.
Sollinger's treatment strategy delivered the genetic code for insulin production into liver cells using an adreno-associated virus that assists in transporting the therapeutic genes across the cells' membrane. This DNA can then take up residence in liver cells, producing insulin without being attacked by the immune system in the pancreas.
While Sollinger had a proof of concept that the therapy worked, he believed the future of the treatment hinged on delivery. He turned to Susan Hagness and John Booske, both UW–Madison professors of electrical and computer engineering who have experience treating human cells with electrical pulses.
"What we started talking about was local, targeted delivery and whether there was a way of getting the treatment DNA directly into the liver without passing it through the entire body and triggering the immune system," says Hagness. "And whether we could use electric pulses in order to make this delivery process more efficient and dramatically reduce the dose needed."
Researchers have previously found that exposing cells to electric fields can often increase the ability of molecules to move through the cell membrane into the interior of a cell. So, in this latest study, PhD student Yizhou Yao sought to determine whether the technique would increase the penetration of virus particles into liver cells.
Using human hepatoma cells, a model system for studying the liver, Yao exposed batches of the cells to various concentrations of the gene therapy virus particles containing a fluorescent green protein. She used a pair of electrodes to deliver an 80-millisecond electric pulse to some samples, then incubated all the cells for 12 hours.
When she examined the results 48 hours later under a fluorescence microscope, Yao found that only a small percentage of the cells that had not received the electrical pulses glowed green. In stark contrast, those cells that had received a zap accumulated about 40 times the amount of the fluorescent green proteins delivered by the virus.
While results provided compelling evidence that the pulses helped facilitate the virus's penetration of the cell walls, Booske says the team has yet to discover exactly how the process works at the molecular level.
"There's enough known about electric pulsing that I think we could confidently state that it is opening nanopores through the cell membrane," he says. "But then Yao got this remarkable result, and it dawned on us that virus particles are in general bigger and more complex than bare molecular particles and they already have their own way of getting inside cells. So, we don't really know if it's the pores opening that has anything to do with it directly or indirectly."
Sollinger passed away in May 2023, but the team says his legacy will live on through the ongoing research on this project and the work of other groups. The electrical engineering researchers are pursuing next steps with external funding and are optimistic that ultimately the technique will translate into clinical trials.
Yao, who will graduate in 2024, says she knew the study would be transdisciplinary, but didn't realize just how far it would go.
"I am an electrical engineer by training, and I don't have a biology background," she says. "Before this, the last time I used a microscope was in high school. It was quite a steep learning curve, learning to culture cells and carry out biology protocols. But I really enjoyed this project and liked its ultimate goal, which is to make the world a better place."
Reference: Yao Y, Holdcraft RW, Hagness SC, Booske JH. Electric pulse exposure reduces AAV8 dosage required to transduce HepG2 cells. Ling C, ed. PLoS ONE. 2024;19(4):e0298866. Doi: 10.1371/journal.Pone.0298866
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