Researchers Get Closer to Gene Editing Treatment for Cardiovascular Disease
Later this year, Verve Therapeutics of Cambridge, Ma., will initiate Phase 1 clinical trials to test VERVE-101, a new medication that, if successful, will employ gene editing to significantly reduce low-density lipoprotein cholesterol, or LDL.
LDL is sometimes referred to as the “bad” cholesterol because it collects in the walls of blood vessels, and high levels can increase chances of a heart attack, cardiovascular disease or stroke. There are approximately 600,000 heart attacks per year due to blood cholesterol damage in the United States, and heart disease is the number one cause of death in the world. According to the CDC, a 10 percent decrease in total blood cholesterol levels can reduce the incidence of heart disease by as much as 30 percent.
Verve’s Founder and CEO, Sekar Kathiresan, spent two decades studying the genetic basis for heart attacks while serving as a professor of medicine at Harvard Medical School. His research led to two critical insights.
“One is that there are some people that are naturally resistant to heart attack and have lifelong, low levels of LDL,” the cardiologist says. “Second, there are some genes that can be switched off that lead to very low LDL cholesterol, and individuals with those genes switched off are resistant to heart attacks.”
Kathiresan and his team formed a hypothesis in 2016 that if they could develop a medicine that mimics the natural protection that some people enjoy, then they might identify a powerful new way to treat and ultimately prevent heart attacks. They launched Verve in 2018 with the goal of creating a one-time therapy that would permanently lower LDL and eliminate heart attacks caused by high LDL.
"Imagine a future where somebody gets a one-time treatment at the time of their heart attack or before as a preventive measure," says Kathiresan.
The medication is targeted specifically for patients who have a genetic form of high cholesterol known as heterozygous familial hypercholesterolemia, or FH, caused by expression of a gene called PCSK9. Verve also plans to develop a program to silence a gene called ANGPTL3 for patients with FH and possibly those with or at risk of atherosclerotic cardiovascular disease.
FH causes cholesterol to be high from birth, reaching levels of 200 to 300 milligrams per deciliter. Suggested normal levels are around 100 to 129 mg/dl, and anything above 130 mg/dl is considered high. Patients with cardiovascular disease usually are asked to aim for under 70 mg/dl, but many still have unacceptably high LDL despite taking oral medications such as statins. They are more likely to have heart attacks in their 30s, 40s and 50s, and require lifelong LDL control.
The goal for drug treatments for high LDL, Kathiresan says, is to reduce LDL as low as possible for as long as possible. Physicians and researchers also know that a sizeable portion of these patients eventually start to lose their commitment to taking their statins and other LDL-controlling medications regularly.
“If you ask 100 patients one year after their heart attack what fraction are still taking their cholesterol-lowering medications, it’s less than half,” says Kathiresan. “So imagine a future where somebody gets a one-time treatment at the time of their heart attack or before as a preventive measure. It’s right in front of us, and it’s something that Verve is looking to do.”
In late 2020, Verve completed primate testing with monkeys that had genetically high cholesterol, using a one-time intravenous injection of VERVE-101. It reduced the monkeys’ LDL by 60 percent and, 18 months later, remains at that level. Kathiresan expects the LDL to stay low for the rest of their lives.
Verve’s gene editing medication is packaged in a lipid nanoparticle to serve as the delivery mechanism into the liver when infused intravenously. The drug is absorbed and makes its way into the nucleus of the liver cells.
Verve’s program targeting PCSK9 uses precise, single base, pair base editing, Kathiresan says, meaning it doesn't cut DNA like CRISPR gene editing systems do. Instead, it changes one base, or letter, in the genome to a different one without affecting the letters around it. Comparing it to a pencil and eraser, he explains that the medication erases out a letter A and makes it a letter G in the A, C, G and T code in DNA.
“We need to continue to advance our approach and tools to make sure that we have the absolute maximum ability to detect off-target effects,” says Euan Ashley, professor of medicine and genetics at Stanford University.
By making that simple change from A to G, the medication switches off the PCSK9 gene, automatically lowering LDL cholesterol.
“Once the DNA change is made, all the cells in the liver will have that single A to G change made,” Kathiresan says. “Then the liver cells divide and give rise to future liver cells, but every time the cell divides that change, the new G is carried forward.”
Additionally, Verve is pursuing its second gene editing program to eliminate ANGPTL3, a gene that raises both LDL and blood triglycerides. In 2010, Kathiresan's research team learned that people who had that gene completely switched off had LDL and triglyceride levels of about 20 and were very healthy with no heart attacks. The goal of Verve’s medication will be to switch off that gene, too, as an option for additional LDL or triglyceride lowering.
“Success with our first drug, VERVE-101, will give us more confidence to move forward with our second drug,” Kathiresan says. “And it opens up this general idea of making [genomic] spelling changes in the liver to treat other diseases.”
The approach is less ethically concerning than other gene editing technologies because it applies somatic editing that affects only the individual patient, whereas germline editing in the patient’s sperm or egg, or in an embryo, gets passed on to children. Additionally, gene editing therapies receive the same comprehensive amount of testing for side effects as any other medicine.
“We need to continue to advance our approach and tools to make sure that we have the absolute maximum ability to detect off-target effects,” says Euan Ashley, professor of medicine and genetics at Stanford University and founding director of its Center for Inherited Cardiovascular Disease. Ashley and his colleagues at Stanford’s Clinical Genomics Program and beyond are increasingly excited about the promise of gene editing.
“We can offer precision diagnostics, so increasingly we’re able to define the disease at a much deeper level using molecular tools and sequencing,” he continues. “We also have this immense power of reading the genome, but we’re really on the verge of taking advantage of the power that we now have to potentially correct some of the variants that we find on a genome that contribute to disease.”
He adds that while the gene editing medicines in development to correct genomes are ahead of the delivery mechanisms needed to get them into the body, particularly the heart and brain, he’s optimistic that those aren’t too far behind.
“It will probably take a few more years before those next generation tools start to get into clinical trials,” says Ashley, whose book, The Genome Odyssey, was published last year. “The medications might be the sexier part of the research, but if you can’t get it into the right place at the right time in the right dose and not get it to the places you don’t want it to go, then that tool is not of much use.”
Medical experts consider knocking out the PCSK9 gene in patients with the fairly common genetic disorder of familial hypercholesterolemia – roughly one in 250 people – a potentially safe approach to gene editing and an effective means of significantly lowering their LDL cholesterol.
Nurse Erin McGlennon has an Implantable Cardioverter Defibrillator and takes medications, but she is also hopeful that a gene editing medication will be developed in the near future.
Erin McGlennon
Mary McGowan, MD, chief medical officer for The Family Heart Foundation in Pasadena, CA, sees the tremendous potential for VERVE-101 and believes patients should be encouraged by the fact that this kind of research is occurring and how much Verve has accomplished in a relatively short time. However, she offers one caveat, since even a 60 percent reduction in LDL won’t completely eliminate the need to reduce the remaining amount of LDL.
“This technology is very exciting,” she said, “but we want to stress to our patients with familial hypercholesterolemia that we know from our published research that most people require several therapies to get their LDL down., whether that be in primary prevention less than 100 mg/dl or secondary prevention less than 70 mg/dl, So Verve’s medication would be an add-on therapy for most patients.”
Dr. Kathiresan concurs: “We expect our medicine to lower LDL cholesterol by about 60 percent and that our patients will be on background oral medications, including statins that lower LDL cholesterol.”
Several leading research centers are investigating gene editing treatments for other types of cardiovascular diseases. Elizabeth McNally, Elizabeth Ward Professor and Director at the Center for Genetic Medicine at Northwestern University’s Feinberg School of Medicine, pursues advanced genetic correction in neuromuscular diseases such as Duchenne muscular dystrophy and spinal muscular atrophy. A cardiologist, she and her colleagues know these diseases frequently have cardiac complications.
“Even though the field is driven by neuromuscular specialists, it’s the first therapies in patients with neuromuscular diseases that are also expected to make genetic corrections in the heart,” she says. “It’s almost like an afterthought that we’re potentially fixing the heart, too.”
Another limitation McGowan sees is that too many healthcare providers are not yet familiar with how to test patients to determine whether or not they carry genetic mutations that need to be corrected. “We need to get more genetic testing done,” she says. “For example, that’s the case with hypertrophic cardiomyopathy, where a lot of the people who probably carry that diagnosis and have never been genetically identified at a time when genetic testing has never been easier.”
One patient who has been diagnosed with hypertrophic cardiomyopathy also happens to be a nurse working in research at Genentech Pharmaceutical, now a member of the Roche Group, in South San Francisco. To treat the disease, Erin McGlennon, RN, has an Implantable Cardioverter Defibrillator and takes medications, but she is also hopeful that a gene editing medication will be developed in the near future.
“With my condition, the septum muscles are just growing thicker, so I’m on medicine to keep my heart from having dangerous rhythms,” says McGlennon of the disease that carries a low risk of sudden cardiac death. “So, the possibility of having a treatment option that can significantly improve my day-to-day functioning would be a major breakthrough.”
McGlennon has some control over cardiovascular destiny through at least one currently available technology: in vitro fertilization. She’s going through it to ensure that her children won't express the gene for hypertrophic cardiomyopathy.
Time to visit your TikTok doc? The good and bad of doctors on social media
Rakhi Patel has carved a hobby out of reviewing pizza — her favorite food — on Instagram. In a nod to her preferred topping, she calls herself thepepperoniqueen. Photos and videos show her savoring slices from scores of pizzerias. In some of them, she’s wearing scrubs — her attire as an inpatient neurology physician associate at Tufts Medical Center in Boston.
“Depending on how you dress your pizza, it can be more nutritious,” said Patel, who suggests a thin crust, sugarless tomato sauce and vegetables galore as healthier alternatives. “There are no boundaries for a health care professional to enjoy pizza.”
Beyond that, “pizza fuels my mental health and makes me happy, especially when loaded with pepperoni,” she said. “If I’m going to be a pizza connoisseur, then I also need to take care of my physical health by ensuring that I get at least three days of exercise per week and eat nutritiously when I’m not eating pizza.”
She’s among an increasing number of health care professionals, including doctors and nurses, who maintain an active persona on social media, according to bioethics researchers. They share their hobbies and interests with people inside and outside the world of medicine, helping patients and the public become acquainted with the humans behind the scrubs or white coats. Other health care experts limit their posts to medical topics, while some opt for a combination of personal and professional commentaries. Depending on the posts, ethical issues may come into play.
“Health care professionals are quite prevalent on social media,” said Mercer Gary, a postdoctoral researcher at The Hastings Center, an independent bioethics research institute in Garrison, New York. “They’ve been posting on #medTwitter for many years, mainly to communicate with one another, but, of course, anyone can see the threads. Most recently, doctors and nurses have become a presence on TikTok.”
On social media, many health care providers perceive themselves to be “humanizing” their profession by coming across as more approachable — “reminding patients that providers are people and workers, as well as repositories of medical expertise,” Gary said. As a result, she noted that patients who are often intimidated by clinicians may feel comfortable enough to overcome barriers to scheduling health care appointments. The use of TikTok in particular may help doctors and nurses connect with younger followers.
When health care providers post on social media, they must bear in mind that they have legal and ethical duties to their patients, profession and society, said Elizabeth Levy, founder and director of Physicians for Justice.
While enduring three years of pandemic conditions, many health care professionals have struggled with burnout, exhaustion and moral distress. “Much health care provider content on social media seeks to expose the difficulties of the work,” Gary added. “TikTok and Instagram reels have shown health care providers crying after losing a patient or exhausted after a night shift in the emergency department.”
A study conducted in Beijing, China and published last year found that TikTok is the world’s most rapidly growing video application, amassing 1.6 billion users in 2021. “More and more patients are searching for information on genitourinary cancers via TikTok,” the study’s authors wrote in Frontiers in Oncology, referring to cancers of the urinary tracts and male reproductive organs. Among the 61 sample videos examined by the researchers, health care practitioners contributed the content in 29, or 47 percent, of them. Yet, 22 posts, 36 percent, were misinformative, mostly due to outdated information.
More than half of the videos offered good content on disease symptoms and examinations. The authors concluded that “most videos on genitourinary cancers on TikTok are of poor to medium quality and reliability. However, videos posted by media agencies enjoyed great public attention and interaction. Medical practitioners could improve the video quality by cooperating with media agencies and avoiding unexplained terminologies.”
When health care providers post on social media, they must bear in mind that they have legal and ethical duties to their patients, profession and society, said Elizabeth Levy, founder and director of Physicians for Justice in Irvine, Calif., a nonprofit network of volunteer physicians partnering with public interest lawyers to address the social determinants of health.
“Providers are also responsible for understanding the mechanics of their posts,” such as who can see these messages and how long they stay up, Levy said. As a starting point for figuring what’s acceptable, providers could look at social media guidelines put out by their professional associations. Even beyond that, though, they must exercise prudent judgment. “As social media continues to evolve, providers will also need to stay updated with the changing risks and benefits of participation.”
Patients often research their providers online, so finding them on social media can help inform about values and approaches to care, said M. Sara Rosenthal, a professor and founding director of the program for bioethics and chair of the hospital ethics committee at the University of Kentucky College of Medicine.
Health care providers’ posts on social media also could promote patient education. They can advance informed consent and help patients navigate the risks and benefits of various treatments or preventive options. However, providers could violate ethical principles if they espouse “harmful, risky or questionable therapies or medical advice that is contrary to clinical practice guidelines or accepted standards of care,” Rosenthal said.
Inappropriate self-disclosure also can affect a provider’s reputation, said Kelly Michelson, a professor of pediatrics and director of the Center for Bioethics and Medical Humanities at Northwestern University’s Feinberg School of Medicine. A clinician’s obligations to professionalism extend beyond those moments when they are directly taking care of their patients, she said. “Many experts recommend against clinicians ‘friending’ patients or the families on social media because it blurs the patient-clinician boundary.”
Meanwhile, clinicians need to adhere closely to confidentiality. In sharing a patient’s case online for educational purposes, safeguarding identity becomes paramount. Removing names and changing minor details is insufficient, Michelson said.
“The patient-clinician relationship is sacred, and it can only be effective if patients have 100 percent confidence that all that happens with their clinician is kept in the strictest of confidence,” she said, adding that health care providers also should avoid obtaining information about their patients from social media because it can lead to bias and risk jeopardizing objectivity.
Academic clinicians can use social media as a recruitment tool to expand the pool of research participants for their studies, Michelson said. Because the majority of clinical research is conducted at academic medical centers, large segments of the population are excluded. “This affects the quality of the data and knowledge we gain from research,” she said.
Don S. Dizon, a professor of medicine and surgery at the Warren Alpert Medical School of Brown University in Providence, Rhode Island, uses LinkedIn and Doximity, as well as Twitter, Instagram, TikTok, Facebook, and most recently, YouTube and Post. He’s on Twitter nearly every day, where he interacts with the oncology community and his medical colleagues.
Also, he said, “I really like Instagram. It’s where you will see a hybrid of who I am professionally and personally. I’ve become comfortable sharing both up to a limit, but where else can I combine my appreciation of clothes with my professional life?” On that site, he’s seen sporting shirts with polka dots or stripes and an occasional bow-tie. He also posts photos of his cats.
Don S. Dizon, a professor of medicine and surgery at Brown, started using TikTok several years ago, telling medical stories in short-form videos.
Don S. Dizon
Dizon started using TikTok several years ago, telling medical stories in short-form videos. He may talk about an inspirational patient, his views on end-of-life care and death, or memories of people who have passed. But he is careful not to divulge any details that would identify anyone.
Recently, some people have become his patients after viewing his content on social media or on the Internet in general, which he clearly states isn’t a forum for medical advice. “In both situations, they are so much more relaxed when we meet, because it’s as if they have a sense of who I am as a person,” Dizon said. “I think that has helped so much in talking through a cancer diagnosis and a treatment plan, and yes, even discussions about prognosis.”
He also posts about equity and diversity. “I have found myself more likely to repost or react to issues that are inherently political, including racism, homophobia, transphobia and lack-of-access issues, because medicine is not isolated from society, and I truly believe that medicine is a social justice issue,” said Dizon, who is vice chair of diversity, equity, inclusion and professional integrity at the SWOG Cancer Research Network.
Through it all, Dizon likes “to break through the notion of doctor as infallible and all-knowing, the doctor as deity,” he said. “Humanizing what I do, especially in oncology, is something that challenges me on social media, and I appreciate the opportunities to do it on TikTok.”
Could this habit related to eating slow down rates of aging?
Last Thursday, scientists at Columbia University published a new study finding that cutting down on calories could lead to longer, healthier lives. In the phase 2 trial, 220 healthy people without obesity dropped their calories significantly and, at least according to one test, their rate of biological aging slowed by 2 to 3 percent in over a couple of years. Small though that may seem, the researchers estimate that it would translate into a decline of about 10 percent in the risk of death as people get older. That's basically the same as quitting smoking.
Previous research has shown that restricting calories results in longer lives for mice, worms and flies. This research is unique because it applies those findings to people. It was published in Nature Aging.
But what did the researchers actually show? Why did two other tests indicate that the biological age of the research participants didn't budge? Does the new paper point to anything people should be doing for more years of healthy living? Spoiler alert: Maybe, but don't try anything before talking with a medical expert about it. I had the chance to chat with someone with inside knowledge of the research -- Dr. Evan Hadley, director of the National Institute of Aging's Division of Geriatrics and Clinical Gerontology, which funded the study. Dr. Hadley describes how the research participants went about reducing their calories, as well as the risks and benefits involved. He also explains the "aging clock" used to measure the benefits.
Evan Hadley, Director of the Division of Geriatrics and Clinical Gerontology at the National Institute of Aging
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