New drug for schizophrenia could meet desperate need for better treatments
Schizophrenia is a debilitating mental health condition that affects around 24 million people worldwide. Patients experience hallucinations and delusions when they develop schizophrenia, with experts referring to these new thoughts and behaviors as positive symptoms. They also suffer from negative symptoms in which they lose important functions, suffering from dulled emotions, lack of purpose and social withdrawal.
Currently available drugs can control only a portion of these symptoms but, on August 8th, Karuna Therapeutics announced its completion of a phase 3 clinical trial that found a new drug called KarXT could treat both positive and negative symptoms of schizophrenia. It could mean substantial progress against a problem that has stymied scientists for decades.
A long-standing problem
Since the 1950s, antipsychotics have been used to treat schizophrenia. People who suffer from it are thought to have too much of a brain chemical called dopamine, and antipsychotics work by blocking dopamine receptors in the brain. They can be effective in treating positive symptoms but have little impact on the negative ones, which can be devastating for a patient’s quality of life, making it difficult to maintain employment and have successful relationships. About 30 percent of schizophrenia patients don't actually respond to antipsychotics at all. Current drugs can also have adverse side effects including elevated cholesterol, high blood pressure, diabetes and movements that patients cannot control.
The recent clinical trial heralds a new treatment approach. “We believe it marks an important advancement for patients given its new and completely different mechanism of action from current therapies,” says Andrew Miller, COO of Karuna.
Scientists have been looking to develop alternatives. However, “the field of drug treatment of schizophrenia is currently in the doldrums,” says Peter McKenna, a senior researcher at FIDMAG Research Foundation in Spain which specialises in mental health.
In the 2000s there was a major push to target a brain receptor for a chemical called glutamate. Evidence suggested that this receptor is abnormal in the brains of schizophrenia patients, but attempts to try glutamate failed in clinical trials.
After that, many pharmaceutical companies dropped out of the race for a more useful treatment. But some companies continued to search, such as Karuna Therapeutics, led by founder and Chief Operating Officer Andrew Miller and CEO Steve Paul. The recent clinical trial suggests their persistence has led to an important breakthrough with their drug, KarXT. “We believe it marks an important advancement for patients given its new and completely different mechanism of action from current therapies,” Miller says.
How it works
Neurotransmitters are chemical messengers that pass signals between neurons. To work effectively, neurotransmitters need a receptor to bind to. A neurotransmitter called acetylcholine seems to be especially important in schizophrenia. It interacts with sites called muscarinic receptors, which are involved in the network of nerves that calm your body after a stressful event. Post mortem studies in people with schizophrenia have shown that two muscarinic receptors in the brain, the M1 and M4 receptors, are activated at unusually low levels because they don’t receive enough signals from acetylcholine.
The M4 receptor appears to play a role in psychosis. The M1 receptor is also associated with psychosis but is primarily thought to be involved in cognition. KarXT, taken orally, works by activating both of these receptors to signal properly. It is this twofold action that seems to explain its effectiveness. “[The drug’s] design enables the preferential stimulation of these muscarinic receptors in the brain,” Miller says.
How it developed
It all started in the early 1990s when Paul was at pharmaceutical company Eli Lilly. He discovered that Xanomeline, the drug they were testing on Alzheimer's patients, had antipsychotic effects. It worked by stimulating M1 and M4 receptors, so he and his colleagues decided to test Xanomeline on schizophrenia patients, supported by research on the connection between muscarinic receptors and psychosis. They found that Xanomeline reduced both positive and negative symptoms.
Unfortunately, it also caused significant side effects. The problem was that stimulating the M1 and M4 receptors in the brain also stimulated muscarinic receptors in the body that led to severe vomiting, diarrhea and even the temporary loss of consciousness.
In the end, Eli Lilly discontinued the clinical trials for the drug, but Miller set up Karuna Therapeutics to develop a solution. “I was determined to find a way to harness the therapeutic benefit demonstrated in studies of Xanomeline, while eliminating side effects that limited its development,” Miller says.
He analysed over 7,000 possible ways of mixing Xanomeline with other agents before settling on KarXT. It combines Xanomeline with a drug called Trospium Chloride, which blocks muscarinic receptors in the body – taking care of the side effects such as vomiting – but leaves them unblocked in the brain. Paul was so excited by Miller’s progress that he joined Karuna after leaving Eli Lilly and founding two previous startups.
“It's a very important approach,” says Rick Adams, Future Leaders Fellow in the Institute of Cognitive Neuroscience and Centre for Medical Image Computing at University College London. “We are in desperate need of alternative drug targets and this target is one of the best. There are other alternative targets, but not many are as close to being successful as the muscarinic receptor drug.”
Clinical Trial
Following a successful phase 2 clinical trial in 2019, the most recent trial involved 126 patients who were given KarXT, and 126 who were given a placebo. Compared to the placebo, patients taking KarXT had a significant 9.6 point reduction in the positive and negative syndrome scale (PANSS), the standard for rating schizophrenic symptoms.
KarXT also led to statistically significant declines in positive and negative symptoms compared to the placebo. “The results suggest that KarXT could be a potentially game-changing option in the management of both positive and negative symptoms of schizophrenia,” Miller says.
Robert McCutcheon, a psychiatrist and neuroscientist at Oxford University, is optimistic about the side effects but highlights the need for more safety trials.
McKenna, the researcher at FIDMAG Foundation, agrees about the drug’s potential. “The new [phase 3] study is positive,” he says. “It is reassuring that one is not dealing with a drug that works in one trial and then inexplicably fails in the next one.”
Robert McCutcheon, a psychiatrist and neuroscientist at Oxford University, said the drug is an unprecedented step forward. “KarXT is one of the first drugs with a novel mechanism of action to show promise in clinical trials.”
Even though the drug blocks muscarine receptors in the body, some patients still suffered from adverse side effects like vomiting, dizziness and diarrhea. But in general, these effects were mild to moderate, especially compared to dopamine-blocking antipsychotics or Xanomeline on its own.
McCutcheon is optimistic about the side effects but highlights the need for more safety trials. “The trial results suggest that gastrointestinal side effects appear to be manageable,” he says. “We know, however, from previous antipsychotic drugs that the full picture regarding the extent of side effects can sometimes take longer to become apparent to clinicians and patients. Careful ongoing assessment during a longer period of treatment will therefore be important.”
The Future
The team is currently conducting three other trials to evaluate the efficacy and long-term safety of KarXT. Their goal is to receive FDA approval next year.
Karuna is also conducting trials to evaluate the effectiveness of KarXT in treating psychosis in patients suffering from Alzheimer’s.
The big hope is that they will soon be able to provide a radically different drug to help many patients with schizophrenia. “We are another step closer to potentially providing the first new class of medicine in more than 50 years to the millions of people worldwide living with schizophrenia,” says Miller.
Artificial Wombs Are Getting Closer to Reality for Premature Babies
In 2017, researchers at the Children's Hospital of Philadelphia grew extremely preterm lambs from hairless to fluffy inside a "biobag," a dark, fluid-filled bag designed to mimic a mother's womb.
"There could be quite a lot of infants that would benefit from artificial womb technologies."
This happened over the course of a month, across a delicate period of fetal development that scientists consider the "edge of viability" for survival at birth.
In 2019, Australian and Japanese scientists repeated the success of keeping extremely premature lambs inside an artificial womb environment until they were ready to survive on their own. Those researchers are now developing a treatment strategy for infants born at "the hard limit of viability," between 20 and 23 weeks of gestation. At the same time, Dutch researchers are going so far as to replicate the sound of a mother's heartbeat inside a biobag. These developments signal exciting times ahead--with a touch of science fiction--for artificial womb technologies. But is there a catch?
"There could be quite a lot of infants that would benefit from artificial womb technologies," says Josephine Johnston, a bioethicist and lawyer at The Hastings Center, an independent bioethics research institute in New York. "These technologies can decrease morbidity and mortality for infants at the edge of viability and help them survive without significant damage to the lungs or other problems," she says.
It is a viewpoint shared by Frans van de Vosse, leader of the Cardiovascular Biomechanics research group at Eindhoven University of Technology in the Netherlands. He participates in a university project that recently received more than $3 million in funding from the E.U. to produce a prototype artificial womb for preterm babies between 24 and 28 weeks of gestation by 2024.
The Eindhoven design comes with a fluid-based environment, just like that of the natural womb, where the baby receives oxygen and nutrients through an artificial placenta that is connected to the baby's umbilical cord. "With current incubators, when a respiratory device delivers oxygen into the lungs in order for the baby to breathe, you may harm preterm babies because their lungs are not yet mature for that," says van de Vosse. "But when the lungs are under water, then they can develop, they can mature, and the baby will receive the oxygen through the umbilical cord, just like in the natural womb," he says.
His research team is working to achieve the "perfectly natural" artificial womb based on strict mathematical models and calculations, van de Vosse says. They are even employing 3D printing technology to develop the wombs and artificial babies to test in them--the mannequins, as van de Vosse calls them. These mannequins are being outfitted with sensors that can replicate the environment a fetus experiences inside a mother's womb, including the soothing sound of her heartbeat.
"The Dutch study's artificial womb design is slightly different from everything else we have seen as it encourages a gestateling to experience the kind of intimacy that a fetus does in pregnancy," says Elizabeth Chloe Romanis, an assistant professor in biolaw at Durham Law School in the U.K. But what is a "gestateling" anyway? It's a term Romanis has coined to describe neither a fetus nor a newborn, but an in-between artificial stage.
"Because they aren't born, they are not neonates," Romanis explains. "But also, they are not inside a pregnant person's body, so they are not fetuses. In an artificial womb the fetus is still gestating, hence why I call it gestateling."
The terminology is not just a semantic exercise to lend a name to what medical dictionaries haven't yet defined. "Gestatelings might have a slightly different psychology," says Romanis. "A fetus inside a mother's womb interacts with the mother. A neonate has some kind of self-sufficiency in terms of physiology. But the gestateling doesn't do either of those things," she says, urging us to be mindful of the still-obscure effects that experiencing early life as a gestateling might have on future humans. Psychology aside, there are also legal repercussions.
The Universal Declaration of Human Rights proclaims the "inalienable rights which everyone is entitled to as a human being," with "everyone" including neonates. However, such a legal umbrella is absent when it comes to fetuses, which have no rights under the same declaration. "We might need a new legal category for a gestateling," concludes Romanis.
But not everyone agrees. "However well-meaning, a new legal category would almost certainly be used to further erode the legality of abortion in countries like the U.S.," says Johnston.
The "abortion war" in the U.S. has risen to a crescendo since 2019, when states like Missouri, Mississippi, Kentucky, Louisiana and Georgia passed so-called "fetal heartbeat bills," which render an abortion illegal once a fetal heartbeat is detected. The situation is only bound to intensify now that Justice Ruth Bader Ginsburg, one of the Supreme Court's fiercest champions for abortion rights, has passed away. If President Trump appoints Ginsburg's replacement, he will probably grant conservatives on the Court the votes needed to revoke or weaken Roe v. Wade, the milestone decision of 1973 that established women's legal right to an abortion.
"A gestateling with intermediate status would almost certainly be considered by some in the U.S. (including some judges) to have at least certain legal rights, likely including right-to-life," says Johnston. This would enable a fetus on the edge of viability to make claims on the mother, and lead either to a shortening of the window in which abortion is legal—or a practice of denying abortion altogether. Instead, Johnston predicts, doctors might offer to transfer the fetus to an artificial womb for external gestation as a new standard of care.
But the legal conundrum does not stop there. The viability threshold is an estimate decided by medical professionals based on the clinical evidence and the technology available. It is anything but static. In the 1970s when Roe v. Wade was decided, for example, a fetus was considered legally viable starting at 28 weeks. Now, with improved technology and medical management, "the hard limit today is probably 20 or 21 weeks," says Matthew Kemp, associate professor at the University of Western Australia and one of the Australian-Japanese artificial womb project's senior researchers.
The changing threshold can result in situations where lots of people invested in the decision disagree. "Those can be hard decisions, but they are case-by-case decisions that families make or parents make with the key providers to determine when to proceed and when to let the infant die. Usually, it's a shared decision where the parents have the final say," says Johnston. But this isn't always the case.
On May 9th 2016, a boy named Alfie Evans was born in Liverpool, UK. Suffering seizures a few months after his birth, Alfie was diagnosed with an unknown neurodegenerative disorder and soon went into a semi-vegetative state, which lasted for more than a year. Alfie's medical team decided to withdraw his ventilation support, suggesting further treatment was unlawful and inhumane, but his parents wanted permission to fly him to a hospital in Rome and attempt to prolong his life there. In the end, the case went all the way up to the Supreme Court, which ruled that doctors could stop providing life support for Alfie, saying that the child required "peace, quiet and privacy." What happened to little Alfie raised huge publicity in the UK and pointedly highlighted the dilemma of whether parents or doctors should have the final say in the fate of a terminally-ill child in life-support treatment.
"In a few years from now, women who cannot get pregnant because of uterine infertility will be able to have a fully functional uterus made from their own tissue."
Alfie was born and, thus had legal rights, yet legal and ethical mayhem arose out of his case. When it comes to gestatelings, the scenarios will be even more complicated, says Romanis. "I think there's a really big question about who has parental rights and who doesn't," she says. "The assisted reproductive technology (ART) law in the U.K. hasn't been updated since 2008....It certainly needs an update when you think about all the things we have done since [then]."
This June, for instance, scientists from the Wake Forest Institute for Regenerative Medicine in North Carolina published research showing that they could take a small sample of tissue from a rabbit's uterus and create a bioengineered uterus, which then supported both fertilization and normal pregnancy like a natural uterus does.
"In [a number of] years from now, women who cannot get pregnant because of uterine infertility will be able to have a fully functional uterus made from their own tissue," says Dr. Anthony Atala, the Institute's director and a pioneer in regenerative medicine. These bioengineered uteri will eventually be covered by insurance, Atala expects. But when it comes to artificial wombs that externally gestate premature infants, will all mothers have equal access?
Medical reports have already shown racial and ethnic disparities in infertility treatments and access to assisted reproductive technologies. Costs on average total $12,400 per cycle of treatment and may require several cycles to achieve a live birth. "There's no indication that artificial wombs would be treated any differently. That's what we see with almost every expensive new medical technology," says Johnston. In a much more dystopian future, there is even a possibility that inequity in healthcare might create disturbing chasms in how women of various class levels bear children. Romanis asks us to picture the following scenario:
We live in a world where artificial wombs have become mainstream. Most women choose to end their pregnancies early and transfer their gestatelings to the care of machines. After a while, insurers deem full-term pregnancy and childbirth a risky non-necessity, and are lobbying to stop covering them altogether. Wealthy white women continue opting out of their third trimesters (at a high cost), since natural pregnancy has become a substandard route for poorer women. Those women are strongly judged for any behaviors that could risk their fetus's health, in contrast with the machine's controlled environment. "Why are you having a coffee during your pregnancy?" critics might ask. "Why are you having a glass of red wine? If you can't be perfect, why don't you have it the artificial way?"
Problem is, even if they want to, they won't be able to afford it.
In a more sanguine version, however, the artificial wombs are only used in cases of prematurity as a life-saving medical intervention rather than as a lifestyle accommodation. The 15 million babies who are born prematurely each year and may face serious respiratory, cardiovascular, visual and hearing problems, as well as learning disabilities, instead continue their normal development in artificial wombs. After lots of deliberation, insurers agree to bear the cost of external wombs because they are cheaper than a lifetime of medical care for a disabled or diseased person. This enables racial and ethnic minority women, who make up the majority of women giving premature birth, to access the technology.
Even extremely premature babies, those babies (far) below the threshold of 28 weeks of gestation, half of which die, could now discover this thing called life. In this scenario, as the Australian researcher Kemp says, we are simply giving a good shot at healthy, long-term survival to those who were unfortunate enough to start too soon.
Real-Time Monitoring of Your Health Is the Future of Medicine
The same way that it's harder to lose 100 pounds than it is to not gain 100 pounds, it's easier to stop a disease before it happens than to treat an illness once it's developed.
In Morris' dream scenario "everyone will be implanted with a sensor" ("…the same way most people are vaccinated") and the sensor will alert people to go to the doctor if something is awry.
Bio-engineers working on the next generation of diagnostic tools say today's technology, such as colonoscopies or mammograms, are reactionary; that is, they tell a person they are sick often when it's too late to reverse course. Surveillance medicine — such as implanted sensors — will detect disease at its onset, in real time.
What Is Possible?
Ever since the Human Genome Project — which concluded in 2003 after mapping the DNA sequence of all 30,000 human genes — modern medicine has shifted to "personalized medicine." Also called, "precision health," 21st-century doctors can in some cases assess a person's risk for specific diseases from his or her DNA. The information enables women with a BRCA gene mutation, for example, to undergo more frequent screenings for breast cancer or to pro-actively choose to remove their breasts, as a "just in case" measure.
But your DNA is not always enough to determine your risk of illness. Not all genetic mutations are harmful, for example, and people can get sick without a genetic cause, such as with an infection. Hence the need for a more "real-time" way to monitor health.
Aaron Morris, a postdoctoral researcher in the Department of Biomedical Engineering at the University of Michigan, wants doctors to be able to predict illness with pinpoint accuracy well before symptoms show up. Working in the lab of Dr. Lonnie Shea, the team is building "a tiny diagnostic lab" that can live under a person's skin and monitor for illness, 24/7. Currently being tested in mice, the Michigan team's porous biodegradable implant becomes part of the body as "cells move right in," says Morris, allowing engineered tissue to be biopsied and analyzed for diseases. The information collected by the sensors will enable doctors to predict disease flareups, such as for cancer relapses, so that therapies can begin well before a person comes out of remission. The technology will also measure the effectiveness of those therapies in real time.
In Morris' dream scenario "everyone will be implanted with a sensor" ("…the same way most people are vaccinated") and the sensor will alert people to go to the doctor if something is awry.
While it may be four or five decades before Morris' sensor becomes mainstream, "the age of surveillance medicine is here," says Jamie Metzl, a technology and healthcare futurist who penned Hacking Darwin: Genetic Engineering and the Future of Humanity. "It will get more effective and sophisticated and less obtrusive over time," says Metzl.
Already, Google compiles public health data about disease hotspots by amalgamating individual searches for medical symptoms; pill technology can digitally track when and how much medication a patient takes; and, the Apple watch heart app can predict with 85-percent accuracy if an individual using the wrist device has Atrial Fibrulation (AFib) — a condition that causes stroke, blood clots and heart failure, and goes undiagnosed in 700,000 people each year in the U.S.
"We'll never be able to predict everything," says Metzl. "But we will always be able to predict and prevent more and more; that is the future of healthcare and medicine."
Morris believes that within ten years there will be surveillance tools that can predict if an individual has contracted the flu well before symptoms develop.
At City College of New York, Ryan Williams, assistant professor of biomedical engineering, has built an implantable nano-sensor that works with a florescent wand to scope out if cancer cells are growing at the implant site. "Instead of having the ovary or breast removed, the patient could just have this [surveillance] device that can say 'hey we're monitoring for this' in real-time… [to] measure whether the cancer is maybe coming back,' as opposed to having biopsy tests or undergoing treatments or invasive procedures."
Not all surveillance technologies that are being developed need to be implanted. At Case Western, Colin Drummond, PhD, MBA, a data scientist and assistant department chair of the Department of Biomedical Engineering, is building a "surroundable." He describes it as an Alexa-style surveillance system (he's named her Regina) that will "tell" the user, if a need arises for medication, how much to take and when.
Bioethical Red Flags
"Everyone should be extremely excited about our move toward what I call predictive and preventive health care and health," says Metzl. "We should also be worried about it. Because all of these technologies can be used well and they can [also] be abused." The concerns are many layered:
Discriminatory practices
For years now, bioethicists have expressed concerns about employee-sponsored wellness programs that encourage fitness while also tracking employee health data."Getting access to your health data can change the way your employer thinks about your employability," says Keisha Ray, assistant professor at the University of Texas Health Science Center at Houston (UTHealth). Such access can lead to discriminatory practices against employees that are less fit. "Surveillance medicine only heightens those risks," says Ray.
Who owns the data?
Surveillance medicine may help "democratize healthcare" which could be a good thing, says Anita Ho, an associate professor in bioethics at both the University of California, San Francisco and at the University of British Columbia. It would enable easier access by patients to their health data, delivered to smart phones, for example, rather than waiting for a call from the doctor. But, she also wonders who will own the data collected and if that owner has the right to share it or sell it. "A direct-to-consumer device is where the lines get a little blurry," says Ho. Currently, health data collected by Apple Watch is owned by Apple. "So we have to ask bigger ethical questions in terms of what consent should be required" by users.
Insurance coverage
"Consumers of these products deserve some sort of assurance that using a product that will predict future needs won't in any way jeopardize their ability to access care for those needs," says Hastings Center bioethicist Carolyn Neuhaus. She is urging lawmakers to begin tackling policy issues created by surveillance medicine, now, well ahead of the technology becoming mainstream, not unlike GINA, the Genetic Information Nondiscrimination Act of 2008 -- a federal law designed to prevent discrimination in health insurance on the basis of genetic information.
And, because not all Americans have insurance, Ho wants to know, who's going to pay for this technology and how much will it cost?
Trusting our guts
Some bioethicists are concerned that surveillance technology will reduce individuals to their "risk profiles," leaving health care systems to perceive them as nothing more than a "bundle of health and security risks." And further, in our quest to predict and prevent ailments, Neuhaus wonders if an over-reliance on data could damage the ability of future generations to trust their gut and tune into their own bodies?
It "sounds kind of hippy-dippy and feel-goodie," she admits. But in our culture of medicine where efficiency is highly valued, there's "a tendency to not value and appreciate what one feels inside of their own body … [because] it's easier to look at data than to listen to people's really messy stories of how they 'felt weird' the other day. It takes a lot less time to look at a sheet, to read out what the sensor implanted inside your body or planted around your house says."
Ho, too, worries about lost narratives. "For surveillance medicine to actually work we have to think about how we educate clinicians about the utility of these devices and how to how to interpret the data in the broader context of patients' lives."
Over-diagnosing
While one of the goals of surveillance medicine is to cut down on doctor visits, Ho wonders if the technology will have the opposite effect. "People may be going to the doctor more for things that actually are benign and are really not of concern yet," says Ho. She is also concerned that surveillance tools could make healthcare almost "recreational" and underscores the importance of making sure that the goals of surveillance medicine are met before the technology is unleashed.
"We can't just assume that any of these technologies are inherently technologies of liberation."
AI doesn't fix existing healthcare problems
"Knowing that you're going to have a fall or going to relapse or have a disease isn't all that helpful if you have no access to the follow-up care and you can't afford it and you can't afford the prescription medication that's going to ward off the onset," says Neuhaus. "It may still be worth knowing … but we can't fool ourselves into thinking that this technology is going to reshape medicine in America if we don't pay attention to … the infrastructure that we don't currently have."
Race-based medicine
How surveillances devices are tested before being approved for human use is a major concern for Ho. In recent years, alerts have been raised about the homogeneity of study group participants — too white and too male. Ho wonders if the devices will be able to "accurately predict the disease progression for people whose data has not been used in developing the technology?" COVID-19 has killed Black people at a rate 2.5 time greater than white people, for example, and new, virtual clinical research is focused on recruiting more people of color.
The Biggest Question
"We can't just assume that any of these technologies are inherently technologies of liberation," says Metzl.
Especially because we haven't yet asked the 64-thousand dollar question: Would patients even want to know?
Jenny Ahlstrom is an IT professional who was diagnosed at 43 with multiple myeloma, a blood cancer that typically attacks people in their late 60s and 70s and for which there is no cure. She believes that most people won't want to know about their declining health in real time. People like to live "optimistically in denial most of the time. If they don't have a problem, they don't want to really think they have a problem until they have [it]," especially when there is no cure. "Psychologically? That would be hard to know."
Ahlstrom says there's also the issue of trust, something she experienced first-hand when she launched her non-profit, HealthTree, a crowdsourcing tool to help myeloma patients "find their genetic twin" and learn what therapies may or may not work. "People want to share their story, not their data," says Ahlstrom. "We have been so conditioned as a nation to believe that our medical data is so valuable."
Metzl acknowledges that adoption of new technologies will be uneven. But he also believes that "over time, it will be abundantly clear that it's much, much cheaper to predict and prevent disease than it is to treat disease once it's already emerged."
Beyond cost, the tremendous potential of these technologies to help us live healthier and longer lives is a game-changer, he says, as long as we find ways "to ultimately navigate this terrain and put systems in place ... to minimize any potential harms."